Search result for -

Sort by:

Title:

The persistence of container nursery treatments on the field performance and root system morphology of longleaf pine seedlings

Author:

Sung, S. S.

Dumroese, R. K.

Pinto, J. R.

Sayer, M. A. S.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

In recent decades, container stock has become the preferred plant material to regenerate longleaf pine (Pinus palustris Mill.) forests in the southeastern United States. We evaluated the effects of container nursery treatments on early and long-term field performance in central Louisiana. Seedlings were grown in four cavity volumes (60–336 mL) with or without copper oxychloride root pruning (Cu or no-Cu) and fertilized at three nitrogen (N) rates. Across treatments, 91% of the seedlings emerged from the grass stage by the second field season, and 88% of the seedlings survived eight years after outplanting (Year 8). Seedlings grown in the largest cavities had greater total heights and stem diameters than those cultured in the 60- and 95-mL cavities through Year 8. Seedlings receiving the least amount of N in the nursery were consistently smaller in stature through Year 8 than seedlings receiving more N. Field growth was unaffected by copper root pruning through Year 8. Foliar mineral nutrient concentrations and seedling nutrient contents of Year 2 seedlings did not respond to nursery treatments. Independent of nursery treatments, seedlings excavated in Year 2 had at least 60% of their first-order lateral roots (FOLRs) originating from the top 4.0 cm of the taproots. The Cu-root-pruned seedlings had twofold the percentage of FOLRs egressed from the top 8.0 cm of the root plug when compared with the no-Cu seedlings. Moreover, the Cu root pruning treatment decreased the percentage of root plug biomass allocated to FOLRs, total within root plug FOLR lengths, and FOLR deformity index. The effects of increasing cavity volume or N rate on the root plug FOLR variables were opposite those of the Cu root pruning treatment. Our results suggest that a tradeoff may exist between seedling stature and a more natural FOLR morphology in outplanted container longleaf pine seedlings.

Title:

Association between severity of prescribed burns and subsequent activity of conifer-infesting beetles in stands of longleaf pine

Author:

Sullivan, B. T.

Fettig, C. J.

Otrosina, W. J.

Dalusky, M. J.

Berisford, C. W.

Year published:

2003

Publication Type:

None

Abstract:

A randomized complete block experiment was performed to measure the effect of prescribed, dormant-season burns of three different levels of severity (measured as fuel consumption and soil surface heating) on subsequent insect infestation and mortality of mature longleaf pine (Pinus palustris Mill.). Multiple-funnel traps baited with a low release rate of turpentine and ethanol were used to monitor activity of certain coniferophagous beetles. Non-aggressive species, including the root beetles Hylastes salebrosus Eichhoff and H. tenuis Eichhoff, the ambrosia beetle Xyleborus pubescens Zimmermann, the reproduction weevil Pachylobius picivorus (Germar), and buprestid borers, were attracted to burned plots in numbers that correlated positively with burn severity. Beetle attraction to burned sites was greatest in the first weeks post-burn and disappeared by the second year. Two potential tree-killing bark beetles, Dendroctonus terebrans (Olivier) and Ips grandicollis (Eichhoff), were trapped in significant numbers but exhibited no attraction to burned plots. Tree mortality correlated significantly with the severity of the burns and amounted to 5% of stems in the hottest burn treatment after 3 years. The majority of the mortality was observed in the second and third years post-burn. Attacks of Ips and Dendroctonus bark beetles were apparent on nearly all dead or dying trees, and evidence suggested that root pathogens may have contributed to tree susceptibility to beetle attack and mortality. Our data indicate that selection of burn regimes that reduce or eliminate consumption of duff (e.g., favoring heading fires over backing fires) could significantly reduce mortality of longleaf pine managed for long rotations.

Title:

Alternative states and positive feedbacks in restoration ecology

Author:

Suding, K. N.

Gross, K. L.

Houseman, G. R.

Year published:

2004

Publication Type:

Peer-reviewed literature

Abstract:

There is increasing interest in developing better predictive tools and a broader conceptual framework to guide the restoration of degraded land. Traditionally, restoration efforts have focused on re-establishing historical disturbance regimes or abiotic conditions, relying on successional processes to guide the recovery of biotic communities. However, strong feedbacks between biotic factors and the physical environment can alter the efficacy of these successional-based management efforts. Recent experimental work indicates that some degraded systems are resilient to traditional restoration efforts owing to constraints such as changes in landscape connectivity and organization, loss of native species pools, shifts in species dominance, trophic interactions and/or invasion by exotics, and concomitant effects on biogeochemical processes. Models of alternative ecosystem states that incorporate system thresholds and feedbacks are now being applied to the dynamics of recovery in degraded systems and are suggesting ways in which restoration can identify, prioritize and address these constraints.

Title:

Relative effects of disturbance on red imported fire ants and native ant species in a longleaf pine ecosystem

Author:

Stuble, K. L.

Kirkman, L. K.

Carrol, C. R.

Sanders, N. J.

Year published:

2011

Publication Type:

Peer-reviewed literature

Abstract:

The degree to which changes in community composition mediate the probability of colonization and spread of non-native species is not well understood, especially in animal communities. High species richness may hinder the establishment of non-native species. Distinguishing between this scenario and cases in which non-native species become established in intact (lacking extensive anthropogenic soil disturbance) communities and subsequently diminish the abundance and richness of native species is challenging on the basis of observation alone. The red imported fire ant (Solenopsis invicta), an invasive species that occurs throughout much of the southeastern United States, is such an example. Rather than competitively displacing native species, fire ants may become established only in disturbed areas in which native species richness and abundance are already reduced. We used insecticide to reduce the abundance of native ants and fire ants in four experimental plots. We then observed the reassembly and reestablishment of the ants in these plots for 1 year after treatment. The abundance of fire ants in treated plots did not differ from abundance in control plots 1 year after treatment. Likewise, the abundance of native ants increased to levels comparable to those in control plots after 1 year. Our findings suggest that factors other than large reductions in ant abundance and species density (number of species per unit area) may affect the establishment of fire ants and that the response of native ants and fire ants to disturbance can be comparable.

Title:

Habitat characteristics of eastern wild turkey nest and ground roost sites in 2 longleaf pine forests

Author:

Streich, M. M.

Little, A. R.

Chamberlain, M. J.

Conner, L. M.

Warren, R. J.

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

Managing and restoring longleaf pine forests throughout the Southeast is a conservation priority. Prescribed fire is an integral part of these activities, as it is the primary means of controlling hardwood encroachment and maintaining native groundcover. Nest site and preflight brood groundroost site selection of eastern wild turkeys (Meleagris gallopavo silvestris) has not been well studied in longleaf pine systems. Therefore, we determined habitat characteristics associated with wild turkey nests and ground-roosts in 2 longleaf pine forests in southwestern Georgia. We radio-tagged 45 female turkeys and evaluated habitat characteristics associated with 84 nests and 51 ground-roosts during the 2011–2013 nesting seasons. Nests were located farther from mature pine and mature pine-hardwood stands and closer to shrub/scrub habitats than expected. Nests were also negatively associated with percent canopy closure and positively associated with percent woody ground cover and vegetation height. Ground-roosts were closer to mature pine-hardwood stands and open water than were random sites. We suggest that management of longleaf pine forests should focus on maintaining open-canopied forests with adequate understory vegetation to serve as nesting and brood-rearing cover. Our findings suggest that frequent prescribed fire (≤ 2 years), when the management goal is to optimize restoration of longleaf ecosystems, is conducive to maintaining wild turkey populations.

Title:

Analysis of fire frequency on the Talladega National Forest, USA, 1998-2018

Author:

Stober, J.

Merry, K.

Bettinger, P.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Fire is an essential ecological process and management tool for many forested landscapes, particularly the pine (Pinus spp.) forests of the southern USA. Within the Talladega National Forest in Alabama, where restoration and maintenance of pine ecosystems is a priority, fire frequency (both wild and prescribed) was assessed using a geographical process applied to a fire history database. Two methods for assessing fire frequency were employed: (1) a simple method that utilised the entire range of years acknowledged in the database and (2) a conservative method that was applied only the date of the first and last fires recorded at each location. Analyses were further separated by (a) method of mean fire return interval calculation (weighted by area or Weibull) and (b) fire season interval with analyses conducted on growing season and dormant season fires. Analyses of fire frequency for national forest planning purposes may help determine whether a prescribed fire program mimics ecological and historical fire frequencies and meets intended objectives. The estimated fire return interval was between ~5 and 6.5 years using common, straightforward (simple) methods. About one-third of the forest receives no fire management and about half of the balance has sufficiently managed fuels.

Title:

Effects of forest management on amphibians and reptiles: generalist species obscure trends among native forest associates

Author:

Steen, D. A.

McGee, A. E. R.

Hermann, S. M.

Stiles, J. A.

Stiles, S. H.

Guyer, C.

Year published:

2010

Publication Type:

Peer-reviewed literature

Abstract:

In the future, land stewards are expected to increase their use of fire surrogates to manage longleaf pine forests. Varying land management strategies may have disparate effects on wildlife and the strength of these effects may depend upon the degree to which each target species is associated with the longleaf pine forest. To determine how amphibian and reptile assemblages respond to prescribed burns and fire surrogates, we sampled these animals within plots of land managed under four common management practices (burning, thinning, thinning and burning, and application of herbicide) and on unmanaged reference plots. We analyzed these data first by examining the entire herpetofauna and then by repeating all analyses for only taxa exhibiting some evidence of an evolutionary association with longleaf pine forests. We found that estimates of species richness of all amphibians did not differ significantly among treatments. These trends were altered when the pool of taxa was restricted to amphibian species known to be associated with longleaf pine forests. For associated amphibians, species richness was elevated on plots that were exposed to herbicide and burn, hardwood thinning, and hardwood thinning plus prescribed fire, relative to reference plots. No significant trends were identified for squamates in general or those squamate species known to be associated with longleaf forests. Fire surrogates may facilitate conservation for individual species of the ancestral biota of longleaf pine forests, but these trends may be obscured when entire assemblages are considered.

Title:

Habitat loss alters the architecture of plant-pollinator interaction networks

Author:

Spiesman, B. J.

Inouye, B. D.

Year published:

2013

Publication Type:

Peer-reviewed literature

Abstract:

Habitat loss can have a negative effect on the number, abundance, and composition of species in plant—pollinator communities. Although we have a general understanding of the negative consequences of habitat loss for biodiversity, much less is known about the resulting effects on the pattern of interactions in mutualistic networks. Ecological networks formed by mutualistic interactions often exhibit a highly nested architecture with low modularity, especially in comparison with antagonistic networks. These patterns of interaction are thought to confer stability on mutualistic communities. With the growing threat of environmental change, it is important to expand our understanding of the factors that affect biodiversity and the stability of the communities that provide critical ecosystem functions and services. We studied the effects of habitat loss on plant—pollinator network architecture and found that regional habitat loss contributes directly to species loss and indirectly to the reorganization of interspecific interactions in a local community. Networks became more highly connected and more modular with habitat loss. Species richness and abundance were the primary drivers of variation in network architecture, though species compositi n affected modularity. Theory suggests that an increase in modularity with habitat loss will threaten community stability, which may contribute to an extinction debt in communities already affected by habitat loss.

Title:

Conservation of the endangered Pinus palustris ecosystem based on Coastal Plain centers of plant endemism

Author:

Sorrie, B. A.

Weakley, A. S.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

Can the geographic patterning of endemic plant species inform reserve selection in a region of high endemism? Location: The southeastern Coastal Plain of North America, focusing primarily on the imperiled Pinus palustris (longleaf pine) ecosystem. Methods: We documented the high level of plant endemism in the region, and characterized the endemic taxa into distributional subregions. Results: A total of 1630 plant taxa are endemic to the Coastal Plain, a large proportion of which are endemic to phytogeographical subregions within the Coastal Plain, with particularly large numbers of narrow endemics occurring in the East Gulf Coastal Plain and Florida Peninsula. Conclusions: This pattern of local endemism presents challenges in conserving the full biota of the region: a reserve system focusing on few and large conservation areas has theoretical benefits for long-term management and viability, but will fail to capture many local endemics. We propose that the dispersed distribution of endemic species will require a mixture of large core reserves and smaller satellite reserves. Nomenclature: Kartesz (1999) with minor exceptions and modifications and updates from the taxonomic literature. 

Title:

Increasing participation in incentive programs for biodiversity conservation

Author:

Sorice, M. G.

Oh, C.

Gartner, T.

Snieckus, M.

Johnson, R.

Donlan, C. J.

Year published:

2013

Publication Type:

Peer-reviewed literature

Abstract:

Engaging private landowners in conservation activities for imperiled species is critical to maintaining and enhancing biodiversity. Market-based approaches can incentivize conservation behaviors on private lands by shifting the benefit—cost ratio of engaging in activities that result in net conservation benefits for target species. In the United States and elsewhere, voluntary conservation agreements with financial incentives are becoming an increasingly common strategy. While the influence of program design and delivery of voluntary conservation programs is often overlooked, these aspects are critical to achieving the necessary participation to attain landscape-scale outcomes. Using a sample of family-forest landowners in the southeast United States, we show how preferences for participation in a conservation program to protect an at-risk species, the gopher tortoise (Gopherus polyphemus), are related to program structure, delivery, and perceived efficacy. Landowners were most sensitive to programs that are highly controlling, require permanent conservation easements, and put landowners at risk for future regulation. Programs designed with greater levels of compensation and that support landowners' autonomy to make land management decisions can increase participation and increase landowner acceptance of program components that are generally unfavorable, like long-term contracts and permanent easements. There is an inherent trade-off between maximizing participation and maximizing the conservation benefits when designing a conservation incentive program. For conservation programs targeting private lands to achieve landscape-level benefits, they must attract a critical level of participation that creates a connected mosaic of conservation benefits. Yet, programs with attributes that strive to maximize conservation benefits within a single agreement (and reduce risks of failure) are likely to have lower participation, and thus lower landscape benefits. Achieving levels of landowner participation in conservation agreement programs that deliver lasting, landscape-level benefits requires careful attention not only to how the program structure influences potential conservation benefits, but also how it influences landowners and their potential to participate.

Title:

The vertebrate fauna of Ichauway, Baker County, GA

Author:

Smith, L. L.

Steen, D. A.

Stober, J. M.

Freeman, M. C.

Golladay, S. W.

Conner, L. M.

Cochrane, J.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

Less than 4% of the once extensive Pinus palustris (longleaf pine) ecosystem remains today. Although longleaf pine habitats are recognized for their high species diversity, few published accounts document the vertebrate faunas of remaining tracts. Here we report on the vertebrate species richness of Ichauway, an 11,300-ha property in Baker County, GA. The property includes ca. 7300 ha of longleaf pine with native ground cover, along with more than 30 seasonal wetlands and ca. 45 km of riparian habitat associated with Ichawaynochaway Creek, Big Cypress Creek, and the Flint River. The fauna includes 61 species of fish, 31 amphibians, 53 reptiles, 191 birds, and 41 mammals. Despite the relative isolation of the property from other natural ecosystems, the vertebrate fauna of Ichauway is remarkably diverse and may offer an example of reference conditions to guide restoration of longleaf pine forests, associated seasonal wetlands, and riparian areas elsewhere in the southeastern US.

Title:

Contingent resistance in longleaf pine (pinus palustris) growth and defense 10 years following smoldering fires

Author:

Slack, A. W.

Zeibig-Kichas, N. E.

Kane, J. M.

Varner, J. M.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

In many fire-prone woodlands and forests, fire exclusion has resulted in substantial litter and duff accumulations capable of long-duration smoldering once fire is reintroduced. While previous research has shown that the soil heating from smoldering fires resulted in short-term reductions in coarse root non-structural carbohydrates and latewood growth, information on the long-term effects of smoldering fire is lacking. Our study compared the effects of three smoldering fire treatments (root only, stem only, root and stem) and two control treatments (no fire and surface fire only) on longleaf pine (Pinus palustris) growth and defense ten years after treatments. We cored 17–29 similar sized trees per treatment and measured growth as basal area increment and defense as resin duct properties (e.g., resin duct size, % resin duct area). We used generalized linear mixed models to determine the influence of smoldering treatments and climate on basal area increment and resin duct properties. Variation in basal area increment and resin duct size during the previous ten years were positively correlated with the subsequent ten years, r2 = 0.71 and r2 = 0.65, respectively. Additionally, temporal variation in growth and defense were related to climatic factors. Growth had the strongest correlation with current August temperatures (r = 0.50), and defense had the strongest correlation with current December temperatures (r = 0.64). Basal area increment was best predicted by summer and fall Palmer Drought Severity Index, while resin duct size was best predicted by the interaction of treatment and precipitation during the previous November. During the three driest years following treatment smoldering duration had a negative relationship with basal area increment (p < 0.0085; r2 = 0.08) and resin duct size (p < 0.0003; r2 = 0.16). While longleaf pine growth was generally resistant to long-duration soil heating following years of fire exclusion, the proceeding growth response was contingent on the post-fire climate. Longleaf pine resin duct size was sensitive to the effects of smoldering fire, and potential negative impacts may be exacerbated by lower precipitation. Restoring fire to long-unburned sites proceeded by warmer and drier climate conditions may result in reduced longleaf pine growth and defense that may contribute to increased probability of mortality during subsequent disturbances.

Title:

Nitrogen decreases and precipitation increases ectomycorrhizal extramatrical mycelia production in a longleaf pine forest

Author:

Sims, S. E.

Hendricks, J. J.

Mitchell, R. J.

Kuehn, K. A.

Pecot, S. D.

Year published:

2007

Publication Type:

Peer-reviewed literature

Abstract:

The rates and controls of ectomycorrhizal fungal production were assessed in a 22-year-old longleaf pine (Pinus palustris Mill.) plantation using a complete factorial design that included two foliar scorching (control and 95% plus needle scorch) and two nitrogen (N) fertilization (control and 5 g N m−2 year−1) treatments during an annual assessment. Ectomycorrhizal fungi production comprised of extramatrical mycelia, Hartig nets and mantles on fine root tips, and sporocarps was estimated to be 49 g m−2 year−1 in the control treatment plots. Extramatrical mycelia accounted for approximately 95% of the total mycorrhizal production estimate. Mycorrhizal production rates did not vary significantly among sample periods throughout the annual assessment (p = 0.1366). In addition, reduction in foliar leaf area via experimental scorching treatments did not influence mycorrhizal production (p = 0.9374), suggesting that stored carbon (C) may decouple the linkage between current photosynthate production and ectomycorrhizal fungi dynamics in this forest type. Nitrogen fertilization had a negative effect, whereas precipitation had a positive effect on mycorrhizal fungi production (p = 0.0292; r 2 = 0.42). These results support the widely speculated but poorly documented supposition that mycorrhizal fungi are a large and dynamic component of C flow and nutrient cycling dynamics in forest ecosystems

Title:

Imputation of individual longelaf pine (Pinus palustris) tree attributes from field and LiDAR data.

Author:

Silva, C. A.

Hiers, J. K.

Hudak, A. T.

Vierling, L. A.

Loudermilk, E. L.

O'Brien, J. J.

Jack, S. B.

Gonzalez-Benecke, C.

Lee, H.

Falkowski, M. J.

Khosravipour, A.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Light Detection and Ranging (LiDAR) has demonstrated potential for forest inventory at the individual-tree level. The aim in this study was to predict individual-tree height (Ht; m), basal area (BA; m2), and stem volume (V; m3) attributes, imputing Random Forest k-nearest neighbor (RF k-NN) and individual-tree-level-based metrics extracted from a LiDAR-derived canopy height model (CHM) in a longleaf pine (Pinus palustris Mill.) forest in southwestern Georgia, United States. We developed a new framework for modeling tree-level forest attributes that comprise 3 steps: (i) individual tree detection, crown delineation, and tree-level-based metrics computation from LiDAR-derived CHM; (ii) automatic matching of LiDAR-derived trees and field-based trees for a regression modeling step using a novel algorithm; and (iii) RF k-NN imputation modeling for estimating tree-level Ht, BA, and V and subsequent summarization of these metrics at the plot and stand levels. RMSDs for tree-level Ht, BA, and V were 2.96%, 58.62%, and 8.19%, respectively. Although BA estimation accuracy was poor because of the longleaf pine growth habitat, individual-tree locations, Ht, and V were estimated with high accuracy, especially in low-canopy-cover conditions. Future efforts based on the findings could help improve the estimation accuracy of individual-tree-level attributes such as BA.

Title:

Modelling post-fire tree mortality: can random forest improve discrimination of imbalanced data

Author:

Shearman, T. M.

Varner, J. M.

Hood, S. M.

Cansler, C. A.

Hiers, J. K.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Predicting post-fire tree mortality is a major area of research in fire-prone forests, woodlands, and savannas worldwide. Past research has relied overwhelmingly on logistic regression analysis (LR) that predicts post-fire tree status as a binary outcome (i.e. living or dead). One of the most problematic issues for LR (or any classification problem) occurs when there is a class imbalance in the training data. In these instances, predictions will be biased toward the majority class. Using a historical prescribed fire data set of longleaf pines (Pinus palustris) from northern Florida, USA, we compare results from standard LR and the machine-learning algorithm, random forest (RF). First, we demonstrate the class imbalance problem using simulated data. We then show how a balanced RF model can be used to alleviate the bias in the model and improve mortality prediction results. In the simulated example, LR model sensitivity and specificity was clearly biased based on the degree of imbalance between the classes. The balanced RF models had consistent sensitivity and specificity throughout the simulated data sets. Re-analyzing the original longleaf pine data set with a balanced RF model showed that although both LR and RF models had similar areas under the receiver operating curve (AUC), the RF model had better discrimination for predicting new observations of dead trees. Both LR and RF models identified duff consumption and percent crown scorch as important predictors of tree mortality, however the RF model also suggested prefire duff depth as an important predictor. Our analysis highlights LR limitations when data are imbalanced and supports using RF to develop post-fire tree mortality models. We suggest how RF can be incorporated into future tree mortality studies, as well as possible implementation in future decision-support tools.

Title:

Structural diversity of the longleaf pine ecosystem

Author:

Sharma, A.

Cory, B.

McKeithen, J.

Frazier, J.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Structural diversity is an important attribute of forest ecosystems and is related to ecosystem stability, adaptability and resilience as well as biodiversity and productivity. Structural diversity in the longleaf pine (Pinus palustris Mill.) ecosystem, the most diverse ecosystem of North America, has not been well documented, especially across the longleaf pine’s range of occurrence. We utilized data from 919 Forest Inventory and Analysis (FIA) plots of longleaf pine distributed across 9 states of the southeastern United States and classified these plots on the bases of stand origin (natural or artificial), ownership (public or private), burn condition (burned or not burned in the past 5 years), site conditions (xeric, mesic, or hydric), and number of age classes (one or two). For each plot under a classification category, we calculated Shannon diversity index based on 5-cm diameter classes. The structural diversity estimates, based on Shannon diversity indices, were then analyzed for the entire range of the longleaf pine ecosystem. Our findings indicate that the structural diversity varies between 0.00 and 2.20 across the longleaf pine range, with mean and median structural diversity of 1.35 and 1.42, respectively. Stand origin, site condition, ownership, and number of age classes significantly affected mean structural diversity (α = 0.05). Plots with natural origin, mesic or hydric site conditions, public ownership, and two age classes had higher structural diversity. Using the geographic coordinates of each FIA plot and the corresponding Shannon index value, we created a structural diversity distribution map and a hot spot map of the longleaf pine ecosystem. The maps showed that the longleaf pine ecosystem exhibited variable and heterogeneous distribution of structural diversity in the southeastern United States, with southeastern Mississippi and central Alabama areas as the hotspots. Southcentral Georgia exhibited least structural diversity in longleaf pine forests in the southeastern United States.

Title:

Seed bank-vegetation dynamics along a restoration management gradient in pine flatwoods ecosystems of the Florida Gulf Coast

Author:

Sharma, A.

Bohn, K. K.

Jose, S.

Miller, D. L.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Pine flatwoods ecosystems of the Gulf Coastal Plains of the southeastern United States are known for their species richness, mainly contributed by herbaceous groundcover. However, intensive silvicultural operations and exclusion of fire over a large extent of these ecosystems in the past century has led to a serious depletion of groundcover diversity. Consequently, restoration of these ecosystems has become a high priority for ecological management of forests in the area. The present study was carried out at mesic-hydric flatwoods sites in northwest Florida to examine the effects of restoration activities, including varying intensities of thinning and prescribed burning, on the dynamics of the vegetation and the soil seed bank composition and structure. Three site conditions-degraded, partially restored, and restored-representing a restoration management gradient were sampled for aboveground vegetation and soil seed bank. Vegetation and seed bank composition changed following restoration activities. However, there was little effect on the seed bank structure across the site conditions. A total of 24, 59, and 124 species in the aboveground vegetation, and 26, 39, and 64 species in the seed bank were observed in degraded, partially restored, and restored site conditions, respectively. Most of the species in the seed bank were ruderal, although native. The effect of site conditions on seed density and seed species richness and diversity was not statistically significant. However, these characteristics did vary significantly with the soil depth (main effect) where the soil sample was taken. Higher seed densities were observed in top 0-5 and 5-10 cm than 10-15 cm soil depths across all sites. Seed banks tended to resemble each other more than the vegetation and the vegetation and seed bank across all sites. The presence of mostly ruderal species in seed bank in degraded site indicates that seed bank is not a good source of regeneration of typical flatwoods communities.

Title:

Firequent fire reorganizes fungal communities and slows decomposition across a heterogeneous pine savanna landscape

Author:

Semenova-Nelsen, T. A.

Platt, W. J.

Patterson, T. R.

Huffman, J.

Sikes, B. A.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Pyrogenic savannas with a tree–grassland ‘matrix’ experience frequent fires (i.e. every 1– 3 yr). Aboveground responses to frequent fires have been well studied, but responses of fungal litter decomposers, which directly affect fuels, remain poorly known. We hypothesized that each fire reorganizes belowground communities and slows litter decomposition, thereby influencing savanna fuel dynamics. In a pine savanna, we established patches near and away from pines that were either burned or unburned in that year. Within patches, we assessed fungal communities and microbial decomposition of newly deposited litter. Soil variables and plant communities were also assessed as proximate drivers of fungal communities. Fungal communities, but not soil variables or vegetation, differed substantially between burned and unburned patches. Saprotrophic fungi dominated in unburned patches but decreased in richness and relative abundance after fire. Differences in fungal communities with fire were greater in litter than in soils, but unaffected by pine proximity. Litter decomposed more slowly in burned than in unburned patches. Fires drive shifts between fire-adapted and sensitive fungal taxa in pine savannas. Slower fuel decomposition in accordance with saprotroph declines should enhance fuel accumulation and could impact future fire characteristics. Thus, fire reorganization of fungal communities may enhance persistence of these fire-adapted ecosystems.

Title:

The national fire and fire surrogate study: effects of fuel reduction methods on forest vegetation structure and fuels

Author:

Schwilk, D. W.

Keely, J. E.

Knapp, E. E.

McIver, J.

Bailey, J. D.

Fettig, C. J.

Fiedler, C. E.

Harrod, R. J.

Moghaddas, J. J.

Outcalt, K. W.

Skinner, C. N.

Stephens, S. L.

Waldrop, T. A.

Yaussy, D. A.

Youngblood, A.

Year published:

2009

Publication Type:

Peer-reviewed literature

Abstract:

Changes in vegetation and fuels were evaluated from measurements taken before and after fuel reduction treatments (prescribed fire, mechanical treatments, and the combination of the two) at 12 Fire and Fire Surrogate (FFS) sites located in forests with a surface fire regime across the conterminous United States. To test the relative effectiveness of fuel reduction treatments and their effect on ecological parameters we used an information theoretic approach on a suite of 12 variables representing the overstory (basal area and live tree, sapling, and snag density), the understory (seedling density, shrub cover, and native and alien herbaceous species richness), and the most relevant fuel parameters for wildfire damage (height to live crown, total fuel bed mass, forest floor mass, and woody fuel mass). In the short term (one year after treatment), mechanical treatments were more effective at reducing overstory tree density and basal area and at increasing quadratic mean tree diameter. Prescribed fire treatments were more effective at creating snags, killing seedlings, elevating height to live crown, and reducing surface woody fuels. Overall, the response to fuel reduction treatments of the ecological variables presented in this paper was generally maximized by the combined mechanical plus burning treatment. If the management goal is to quickly produce stands with fewer and larger diameter trees, less surface fuel mass, and greater herbaceous species richness, the combined treatment gave the most desirable results. However, because mechanical plus burning treatments also favored alien species invasion at some sites, monitoring and control need to be part of the prescription when using this treatment.

Title:

Longleaf pine stump in Uwharrie Mountains of North Carolina

Author:

Patterson, T. W.

Knapp, P. A.

Year published:

2018

Publication Type:

Peer-reviewed literature

Title:

Observations on a rare old-growth montane longleaf pine forest in central North Carolina, USA

Author:

Patterson, T. W.

Knapp, P. A.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Montane longleaf pine (Pinus palustris) forests are rare and no detailed inventory exists documenting stands in North Carolina. We inventoried all longleaf pine trees (n = 403) growing in a 24-ha remnant montane longleaf pine forest in the Uwharrie Mountains of central North Carolina, USA, in autumn 2014 to (1) map their location, (2) document age/height/diameter characteristics, and (3) determine special ecological features of this rare montane population. All longleaf pine were geographically referenced via GPS, measured for height and diameter, and a subsample of trees was cored to determine age. All longleaf pine were mapped based on growth-stage categories—grass, juvenile, young adult, and mature—to determine spatial patterning of stand-age characteristics. The longleaf pine stand contains a variety of growth-stage categories, but is dominated (63%) by mature-stage trees growing on south- and southwestern-facing slopes, while nearly all regeneration-stage trees (i.e., grass and juvenile) are growing on northwest-facing slopes, suggesting environmental conditions conducive to establishment have changed. Median (maximum) tree height and trunk diameter for young adult and mature were 17 (25) m and 38 (72) cm, respectively. Median (maximum) tree age at 0.3 m height was 116 years (272 years), and at least seven trees were greater than 150 years old, with four trees establishing in the 18th century. We conclude that the stand’s characteristics—400+ trees of various ages including old-growth, occurring principally on steep, southerly slopes with a total relief of 85 m, and extending over 24 ha—warrant “montane” longleaf pine forest status in North Carolina.

Title:

Patch-mosaic burning: a new paradigm for savanna fire management in protected areas

Author:

Parr, C. L.

Brockett, B. H.

Year published:

1999

Publication Type:

Peer-reviewed literature

Abstract:

The shift in ecological thinking, from equilibrium to non-equilibrium processes has been accompanied by a move to encourage heterogeneity rather than homogeneity in landscapes. Spatial and temporal heterogeneity is thought to be a major source of biotic diversity, and disturbances such as fire, producing heterogeneity are now recognized as being important. A patch-mosaic system of burning is based on the premise that fire pattern is a surrogate for diversity, and produces a range of patches in the landscape with unique patch characteristics and fire histories. A patch-mosaic system of burning is supported historically and empirically through field studies. However, there is a need for more research into the effects of various aspects of patch and fire variables on biotic diversity, especially in savannas where out understanding is particularly poor. Landscape-scale experiments, like those to be established in the Kruger National Park, South Africa are necessary to test different burning regimes. Challenges to patch-mosaic burning include determining the ‘natural’ range of variation for fire parameters, implementing random ignitions, and cost-effective fire scare mapping at the appropriate resolution. An adaptive management approach should be adopted to deal with the ignorance and uncertainties that charaterise the management of savanna ecosystems. This should be applied with both modelling and monitoring as key elements in this process.

Title:

Changes in plant species richness following reduced fire frequency and drought in one of the most species-rich savannas in North American

Author:

Palmquist, K. A.

Peet, R. K.

Weakley, A. S.

Year published:

2014

Publication Type:

Peer-reviewed literature

Abstract:

Questions: How has plant species richness changed over two decades in one of the most species-rich savannas in North America? Is an altered disturbance regime, environmental stress, or both, driving these changes? In what ways can observations in this savanna inform management of other species-rich plant communities? Location: Longleaf pine savannas in southeast North Carolina, USA. Methods: In 2011–2013, we re-surveyed permanent plots established in the 1980s and 1990s in a longleaf pine (Pinus palustris) savanna in North Carolina to quantify changes in species richness at multiple spatial scales following 15 yr of reduced fire frequency plus periodic drought. For comparison, we re-sampled other longleaf pine savannas in the region that had not experienced reduced fire frequency, but had experienced similar drought. In addition, we identified which types of species were lost and gained, and summarized changes in species frequency by growth form, plant height, and habitat affinity. Results: We detected substantial declines in small-scale species richness and species frequency from the 1980s to 2011, representing a loss of 33% to 41% of the flora, depending on the spatial scale. Small herbaceous species had become particularly scarce. Additional re-sampling in the wetter years of 2012 and 2013 after consecutive years of fire revealed that species richness had increased slightly from2011, but was still considerably lower than that in the 1980s. Other savannas did not exhibit such dramatic declines in species richness, suggesting reduced fire frequency in addition to drought contributed to species loss in Big Island Savanna over time. Conclusions: Our work suggests that nearly annual fire is necessary for the maintenance of high plant species richness in mesic longleaf pine savannas, and even a modest reduction in fire frequency can have dramatic negative impacts. This study also suggests that drought is an important factor structuring grassland ecosystems in the southeastern US, despite relatively high regional precipitation. We believe these findings can be generalized to other species-rich grasslands that are sensitive to changes in disturbance regimes and may require frequent disturbance to maintain plant species richness.

Title:

Ecological theory and community restoration ecology

Author:

Palmer, M. A.

Ambrose, R. F.

LeRoy Poff, N.

Year published:

1997

Publication Type:

Peer-reviewed literature

Abstract:

Community ecological theory may play an important role in the development of a science of restoration ecology. Not only will the practice of restoration benefit from an increased focus on theory, but basic research in community ecology will also benefit. We pose several major thematic questions that are relevant to restoration from the perspective of community ecological theory and, for each, identify specific areas that are in critical need of further research to advance the science of restoration ecology. We ask, what are appropriate restoration endpoints from a community ecology perspective? The problem of measuring restoration at the community level, particularly given the high amount of variability inherent in most natural communities, is not easy, and may require a focus on restoration of community function (e.g., trophic structure) rather than a focus on the restoration of particular species. We ask, what are the benefits and limitations of using species composition or biodiversity measures as endpoints in restoration ecology? Since reestablishing all native species may rarely be possible, research is needed on the relationship between species richness and community stability of restored sites and on functional redundancy among species in regional colonist “pools.” Efforts targeted at restoring system function must take into account the role of individual species, particularly if some species play a disproportionate role in processing material or are strong interactors. We ask, is restoration of habitat a sufficient approach to reestablish species and function? Many untested assumptions concerning the relationship between physical habitat structure and restoration ecology are being made in practical restoration efforts. We need rigorous testing of these assumptions, particularly to determine how generally they apply to different taxa and habitats. We ask, to what extent can empirical and theoretical work on community succession and dispersal contribute to restoration ecology? We distinguish systems in which succession theory may be broadly applicable from those in which it is probably not. If community development is highly predictable, it may be feasible to manipulate natural succession processes to accelerate restoration. We close by stressing that the science of restoration ecology is so intertwined with basic ecological theory that practical restoration efforts should rely heavily on what is known from theoretical and empirical research on how communities develop and are structured over time.

Title:

Modeling silviculture after natural disturbance to sustain biodiversity in the longleaf pine (Pinus palustris) ecosystem : balancing complexity and implementation

Author:

Palik, B. J.

Mitchell, R. J.

Hiers, J. K.

Year published:

2002

Publication Type:

Peer-reviewed literature

Abstract:

Modeling silviculture after natural disturbance to maintain biodiversity is a popular concept, yet its application remains elusive. We discuss difficulties inherent to this idea, and suggest approaches to facilitate implementation, using longleaf pine (Pinus palustris) as an example. Natural disturbance regimes are spatially and temporally variable. Variability leads to a range of structural outcomes, or results in different pathways leading to similar structures. In longleaf pine, lightning, hurricanes, surface fires, and windthrow all lead to similar structures, but at different rates. Consequently, a manager can select among various natural disturbance patterns when searching for an appropriate silvicultural model. This facilitates management by providing flexibility to meet a range of objectives. The outcomes of natural disturbances are inherently different from those of silviculture, for example, harvesting always removes boles. It is instructive to think of silvicultural disturbances along a gradient in structural outcomes, reflecting degree of disparity with natural disturbance. In longleaf pine this might involve managing for two-cohort structure, instead of multi-cohort structure characteristic of old growth stands. While two-cohort structure is a simplification over the old growth condition, it is an improvement over single-cohort management. Reducing structural disparity between managed and unmanaged forests is key to sustaining biodiversity because of linkages that exist between structural elements, forest biota, and ecosystem processes. Finally, interactions of frequency, severity, intensity, seasonality, and spatial pattern define a disturbance regime. These components may not have equal weight in affecting biodiversity. Some are easier to emulate with silviculture than are others. For instance, ecologists consider growing-season fire more reflective of the natural fire regime in longleaf pine and critical for maintenance of biodiversity. However, dormant season fire is easier to use and recent work with native plants suggests that seasonality of fire may be less critical to maintenance of species richness, as one component of biodiversity, than is generally believed. Science can advance the goal of modeling silviculture after natural disturbances by better illustrating cause and effect relationships among components of disturbance regimes and the structure and function of ecosystems. Wide application requires approaches that are adaptable to different operational situations and landowner objectives. A key point for managers to remember is that strict adherence to a silvicultural regime that closely parallels a natural disturbance regime may not always be necessary to maintain biodiversity. We outline examples of silvicultural systems for longleaf pine that demonstrates these ideas.

Title:

Structure and composition changes following treatments of longleaf pine forests on the Gulf Coastal Plain of Alabama

Author:

Outcalt, K. W.

Brockway, D. G.

Year published:

2010

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine (Pinus palustris Mill.) forests of the Gulf Coastal Plain historically burned every 2–4 years with low intensity fires, which maintained open stands with herbaceous dominated understories. During the early and mid 20th century however, reduced fire frequency allowed fuel to accumulate and hardwoods to increase in the midstory and overstory layers, while woody shrubs gained understory dominance. In 2001, a research study was installed in southern Alabama to develop management options that could be used to reduce fuel loads and restore the ecosystem. As part of a nationwide fire and fire surrogates study, treatments included a control (no fire or other disturbance), prescribed burning only, thinning of selected trees, thinning plus prescribed burning, and herbicide plus prescribed burning. After two cycles of prescribed burning, applied biennially during the growing season, there were positive changes in ecosystem composition. Although thinning treatments produced revenue, while reducing midstory hardwoods and encouraging growth of a grassy understory, burning was needed to discourage regrowth of the hardwood midstory and woody understory. Herbicide application followed by burning gave the quickest changes in understory composition, but repeated applications of fire eventually produced the same results at the end of this 8-year study. Burning was found to be a critical component of any restoration treatment for longleaf communities of this region with positive changes in overstory, midstory and understory layers after just three or four burns applied every 2 or 3 years.

Title:

Effects of habitat and growing season fires on resprouting of shrubs in longleaf pine savannas

Author:

Olson, M. S.

Platt, W. J.

Year published:

1995

Publication Type:

Peer-reviewed literature

Abstract:

The effects of habitat and timing of growing season fires on resprouting of shrubs were studied in second-growth longleaf pine savannas of the west Gulf coastal plain in the southeastern United States. Within the headwaters of three different drainages of the Calcasieu River in the Kisatchie National Forest in western Louisiana, replicated permanent transects were established that extended from xeric upland longleafpine savannas into downslope hydric seepage savannas. All shrubs were mapped and tagged, and numbers of stems were counted prior to any fires. Replicated prescribed fires were set early (June) and late (Augus0 during the 1990 growing season; maximum fire temperatures were measured within both upland and seepage habitats within each transect. Shrubs were relocated; stems were recensused two and twelve months after the fires. At least some shrubs of all species resprouted from underground organs; none regenerated solely from seed banks in the soil. There was no reduction in total numbers of stems one year after fires compared to before fires, either in the upland or in seepage savannas. In addition, there was no reduction in total numbers of stems one year after early or late growing season fires. Fire-related mortality was restricted to small shrubs (< 18 stems) and was not associated with high fire temperatures. The rate of resprouting varied among species and between habitats. Resprouting occurred more rapidly in seepage than upland savannas, but more resprouts were produced in upland than seepage savannas one year after fires. In contrast to other upland species, Vaccinium arboreum and V eUiottii delayed resprouting more than two months following fire. Stems of Rhus copallina and Pyrus arbutifolia, species with long rhizomes, increased more after fires in June than fires in August. We suggest that growing season fires may block further recruitment of shrubs into longleaf pine savannas, but reduction in numbers of large shrubs may require additional management.

Title:

Rarity of shortleaf, slash, and longleaf pine seedlings in oak-pine forest types: an assessment of associated environmental, stand, site, and disturbance factors

Author:

Ojha, S. K.

Naka, K.

Dimov, L. D.

Bhatta, D.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Determining the factors that influence the regeneration of pine in oak-pine forests is crucial for understanding natural regeneration dynamics and for planning forest management strategies. We investigated the vegetation structure and seedling dynamics of shortleaf, slash, and longleaf pine in oak-pine forest types of the southeastern United States. We used logistic regression with penalized maximum likelihood estimation because of the rarity of the regeneration from these pines. We performed canonical correlation, analysis of variance, and community structure analysis to produce multivariate relationships and statistical inferences. The classification accuracy of the logistic regression models for shortleaf, slash, and shortleaf pine were 96.0%, 96.7%, and 97.7%, respectively. The models indicated that environmental, climatic, stand, site productivity, and disturbance factors, or their combinations, had a significant influence on seedling occurrence. The probability of occurrence of seedlings of the three pine species increased with the increase in the overstory basal area from these species: one unit increase in overstory purity ratio of shortleaf, slash, and longleaf pine increased the odds of occurrence of their seedlings by approximately 51, 24, and 7 times, respectively. The probability of occurrence of shortleaf pine seedlings increased with increasing canopy openness in stands with a substantial proportion of shortleaf pine in the overstory. The increase in mean annual temperature and overstory basal area of slash pine increased the probability of occurrence of slash pine seedlings on wetter sites that had disturbance through harvesting and silvicultural treatments. The chances of occurrence of longleaf pine seedlings increased with increasing overstory basal area of longleaf pine, species diversity, and mean annual temperature in low density stands on low productive sites. The findings can help forest managers in designing and implementing silvicultural treatments to promote the natural regeneration of the three pines in oak-pine forests.

Title:

Canopy thinning, not agricultural history, determines early responses of wild bees to longleaf pine savanna restoration.

Author:

Odanaka, K.

Gibbs, J.

Turley, N. E.

Isaacs, R.

Brudvig, L. A.

Year published:

2019

Publication Type:

None

Abstract:

Longleaf pine savannas are highly threatened, fire-maintained ecosystems unique to the southeastern United States. Fire suppression and conversion to agriculture have strongly affected this ecosystem, altering overstory canopies, understory plant communities, and animal populations. Tree thinning to reinstate open canopies can benefit understory plant diversity, but effects on animal communities are less well understood. Moreover, agricultural land-use legacies can have long-lasting impacts on plant communities, but their effects on animal communities either alone or through interactions with restoration are unclear. Resolving these impacts is important due to the conservation potential of fire-suppressed and post-agricultural longleaf savannas. We evaluated how historical agricultural land use and canopy thinning affect the diversity and abundance of wild bees in longleaf pine savannas. We employed a replicated, large-scale factorial block experiment in South Carolina, where canopy thinning was applied to longleaf pine savannas that were either post-agricultural or remnant (no agricultural history). Bees were sampled using elevated bee bowls. In the second growing season after restoration, thinned plots supported a greater bee abundance and bee community richness. Additionally, restored plots had altered wild bee community composition when compared to unthinned plots, indicating that reduction of canopy cover by the thinning treatment best predicted wild bee diversity and composition. Conversely, we found little evidence for differences between sites with or without historical agricultural land use. Some abundant Lasioglossum species were the most sensitive to habitat changes. Our results highlight how restoration practices that reduce canopy cover in fire-suppressed savannas can have rapid benefits for wild bee communities.

Title:

Canopy-derived fuels drive patterns of in-fire energy release and understory plant mortality in a longleaf pine (Pinus palustris) sandhill in northwest Florida, USA

Author:

O'Brien, J. J.

Loudermilk, E. L.

Hiers, J. K.

Pokswinski, S. M.

Hornsby, B.

Hudak, A. T.

Strother, D.

Rowell, E.

Bright, B. C.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Wildland fire radiant energy emission is one of the only measurements of combustion that can be made at high temporal and spatial resolutions. Furthermore, spatially and temporally explicit measurements are critical for making inferences about ecological fire effects. Although the correlation between fire frequency and plant biological diversity in frequently burned coniferous forests is well documented, the ecological mechanisms explaining this relationship remains elusive. Uncovering these mechanisms will require highly resolved, spatially explicit fire data (Loudermilk et al. 2012). Here, we describe our efforts at connecting spatial variability in fuels to fire energy release and fire effects using fine scale (1 cm2) longwave infrared (LWIR) thermal imagery.We expected that the observed variability in fire radiative energy release driven by canopy-derived fuels could be the causal mechanism driving plant mortality, an important component of community dynamics. Analysis of fire radiant energy released in several experimental burns documented a close connection among patterns of fire intensity and plant mortality. Our results also confirmed the significance of cones in driving fine-scale spatial variability of fire intensity. Spatially and temporally resolved data from these techniques show promise to effectively link the combustion environment with postfire processes, remote sensing at larger scales, and wildland fire modeling efforts.

Title:

Acute physiological stress and mortality following fire in a long-unburned longleaf pine ecosystem

Author:

O'Brien, J. J.

Hiers, J. K.

Mitchell, R. J.

Varner, J. M.

Mordecai, K.

Year published:

2010

Publication Type:

Peer-reviewed literature

Abstract:

One important legacy of fire exclusion in ecosystems dependent upon frequent fire is the development of organic soil horizons (forest floor) that can be colonized by fine roots. When fire is re-introduced, the forest floor is often consumed by fire and heavy overstory mortality, often delayed by months, results. We hypothesized that the delayed post-fire tree mortality is a manifestation of a cascade of physiological stresses initiated by root damage that can also magnify the impact of other kinds of damage. We investigated the physiological impact of forest floor consumption on longleaf pines (Pinus palustris Mill.) subjected to a wildfire in 2005 in a long-unburned (>50 years) forest by measuring forest floor consumption, whole tree water use, and leaf chlorophyll content. Ten of the 23 study trees died within three years post fire. Post-fire sap flux was unrelated to crown scorch, but was negatively correlated with forest floor consumption. A segmented linear regression revealed declines in sap flux until a threshold of 31 % forest floor consumption, after which further consumption had no additional effect on tree water use. Trees with >30 % forest floor consumption beneath their crowns were more than 20 times as likely to die as those with less consumption. Chlorophyll content in needles that flushed post fire was negatively correlated with crown scorch (R² = 0.60, P = 0.009) though all trees with scorch also experienced varying degrees of forest floor consumption. Our results suggest that the consumption of the forest floor with the likely concomitant loss of roots initiated a decline spiral, driven by an inability to supply sufficient water to the crown. Though we did not measure loss of stored carbohydrates in consumed roots directly, we infer that this likely effect, coupled with decreased crown photosynthetic capacity, eventually resulted in substantial overstory tree mortality.

Title:

Longleaf pine patch dynamics influence ground-layer vegetation in old-growth pine savanna

Author:

Mugnani, M. P.

Robertson, K. M.

Miller, D. L.

Platt, W. J.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Old-growth longleaf pine savannas are characterized by diverse ground-layer plant communities comprised of graminoids, forbs, and woody plants. These communities co-exist with variable-aged patches containing similar-aged trees of longleaf pine (Pinus palustris Mill.). We tested the conceptual model that physical conditions related to the cycle of longleaf pine regeneration (stand structure, soil attributes, fire effects, and light) influence plant species’ composition and spatial heterogeneity of ground-layer vegetation. We used a chrono-sequence approach in which local patches represented six stages of the regeneration cycle, from open areas without trees (gaps) to trees several centuries old, based on a 40-year population study and increment cores of trees. We measured soil characteristics, patch stand structure, fuel loads and consumption during fires, plant productivity, and ground-layer plant species composition. Patch characteristics (e.g., tree density, basal diameter, soil carbon, and fire heat release) indicated a cyclical pattern that corresponded to the establishment, growth, and mortality of trees over a period of approximately three centuries. We found that plants in the families Fabaceae and Asteraceae and certain genera were significantly associated with a particular patch stage or ranges of patch stages, presumably responding to changes in physical conditions of patches over time. However, whole-community-level analyses did not indicate associations between the patch stage and distinct plant communities. Our study indicates that changes in composition and the structure of pine patches contribute to patterns in spatial and temporal heterogeneity in physical characteristics, fire regimes, and species composition of the ground-layer vegetation in old-growth pine savanna.

Title:

Southern pine beetle infestations in relation to forest stand conditions, previous thinning, and prescribed burning: evaluation of the Souther Pine Beetle Prevention Program

Author:

Nowak, J.

Meeker, J. R.

Coyle, D. R.

Steiner, C. A.

Brownie, C.

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

Since 2003, the Southern Pine Beetle Prevention Program (SPBPP) (a joint effort of the USDA Forest Service and Southern Group of State Foresters) has encouraged and provided cost-share assistance for silvicultural treatments to reduce stand/forest susceptibility to the southern pine beetle (SPB)(Dendroctonus frontalis Zimmermann) in the southeastern United States. Until now, stand- and landscape-level tests of this program’s efficacy were nonexistent. In 2012, SPB outbreaks occurred in the Homochitto and Bienville National Forests (NFs) in Mississippi. Parts of each NF were treated (thinned) using SPBPP management recommendations, whereas other areas were untreated (unthinned). In the Homochitto NF, 99.7% of SPB spots occurred in unthinned stands, whereas all SPB spots occurred in unthinned stands in the Bienville NF. Unthinned stands in both NFs had higher basal area, higher stocking, and lower growth rates over the last decade. Burning also resulted in a lower incidence of SPB infestation. Our retrospective study results validate the effectiveness of SPBPP treatments for reducing stand- and landscape-level susceptibility to SPB, which encourages proper silvicultural methods that increase tree spacing, growth, and vitality, while effectively altering the in-stand atmosphere enough to interfere with SPB pheromone communication, thus reducing susceptibility to SPB spot initiation and spread.

Title:

The southern pine beetle prevention initiative: working for healthier forests

Author:

Nowak, J.

Asaro, C.

Klepzig, K.

Billings, R.

Year published:

2008

Publication Type:

Peer-reviewed literature

Abstract:

The southern pine beetle (SPB) is the most destructive forest pest in the South. After a recent SPB outbreak, the US Forest Service (Forest Health Protection and Southern Research Station [SRS]) received SPB Initiative (SPBI) funding to focus more resources on proactive SPB prevention work. This funding is being used for on-the-ground accomplishments, landowner education, and research and development. Since 2003, on-the-ground accomplishments have totaled over 500,000 ac of thinning and restoration work on state, private, and national forestland. The SRS (SRS Research Work Unit 4552) has worked, internally and externally, on projects addressing (1) the risks and costs of SPB, (2) preventing and controlling SPB outbreaks, and (3) recovery from SPB outbreaks. Much work has been accomplished through the SPBI and will hopefully have a long-lasting impact. This article describes the history, current practices, and the accomplishments for the first 6 years of the SPBI.

Title:

The demise of fire and “mesophication” of forests in the eastern United States

Author:

Nowacki, G. J.

Abrams, M. D.

Year published:

2008

Publication Type:

Peer-reviewed literature

Abstract:

A diverse array of fire-adapted plant communities once covered the eastern United States. European settlement greatly altered fire regimes, often increasing fire occurrence (e.g., in northern hardwoods) or substantially decreasing it (e.g.. in tallgrass prairies). Notwithstanding these changes, fire suppression policies, beginning around the 1920s. greatly reduced fire throughout the East, with profound ecological consequences. Fire-maintained open lands converted to closed-canopy forests. As a result of shading, shade-tolerant, fire-sensitive plants began to replace heliophytic (sun-loving), fire-tolerant plants. A positive feedback cycle—which we term "mesophication"—-ensued, whereby microenvirotmtental conditions (cool, damp, and shaded conditions; less flammable fuel beds) continually improve for shade-tolerant mesophytic species and deteriorate for shade-intolerant, fire-adapted species. Plant communities are undergoing rapid compositional and structural changes, some with no ecological antecedent. Stand-level species richness is declining, and will decline further, as numerous fire-adapted plants are replaced by a limited set of shade-tolerant, fire-sensitive species. As this process continues, the effort and cost required to restore fire-adapted ecosystems escalate rapidly.

Title:

How global biodiversity hotspots may go unrecognized: lessons from the North American Coastal Plain

Author:

Noss, R. F.

Platt, W. J.

Sorrie, B. A.

Weakley, A. S.

Means, D. B.

Costanza, J.

Peet, R. K

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

Biodiversity hotspots are conservation priorities. We identify the North American Coastal Plain (NACP) as a global hotspot based on the classic definition, a region with > 1500 endemic plant species and > 70% habitat loss. This region has been bypassed in prior designations due to misconceptions and myths about its ecology and history. These fallacies include: (1) young age of the NACP, climatic instability over time and submergence during high sea-level stands; (2) climatic and environmental homogeneity; (3) closed forest as the climax vegetation; and (4) fire regimes that are mostly anthropogenic. We show that the NACP is older and more climatically stable than usually assumed, spatially heterogeneous and extremely rich in species and endemics for its range of latitude, especially within pine savannas and other mostly herbaceous and firedependent communities. We suspect systematic biases and misconceptions, in addition to missing information, obscure the existence of similarly biologically significant regions world-wide. Potential solutions to this problem include (1) increased field biological surveys and taxonomic determinations, especially within grassy biomes and regions with low soil fertility, which tend to have much overlooked biodiversity; (2) more research on the climatic refugium role of hotspots, given that regions of high endemism often coincide with regions with low velocity of climate change; (3) in low-lying coastal regions, consideration of the heterogeneity in land area generated by historically fluctuating sea levels, which likely enhanced opportunities for evolution of endemic species; and (4) immediate actions to establish new protected areas and implement science- based management to restore evolutionary environmental conditions in newly recognized hotspots.

Title:

Structural characteristics of old- and second-growth stands of longleaf pine (Pinus palustris) in the Gulf Coastal Region of the USA

Author:

Noel, J. M.

Platt, W. J.

Moser, E. B.

Year published:

1998

Publication Type:

Peer-reviewed literature

Abstract:

Comparisons of old- and second-growth stands of longleaf pine (Pinus palustris) may be useful for setting long-term objectives for the restoration and management of second-growth stands. We quantified structural differences among (1) one xeric old-growth stand, (2) two xeric second-growth stands, and (3) one seasonally flooded flatwoods second-growth stand using quadrats ranging from 100 m2 to 10,000 m2. We estimated the mean density and size of pines, the frequency and size of open spaces, and the scale of aggregation for each stand. The mean density of pines was higher in the two xeric second-growth stands than in the old-growth stand, but variability at the old-growth stand was higher, suggesting discrete patches of densely stocked small trees, interspersed with larger trees and open spaces. This pattern was not present at either xeric second-growth stand. In contrast, the density of trees at the flatwoods site was lower and the frequency of open areas higher than for any other stand. The size class distribution at the old-growth stand was characterized by more small and large trees and fewer intermediate-sized trees than at the second-growth stands. The mean size of all trees at the old-growth stand was larger than at the second-growth stands, but it decreased with increasing quadrat size, reflecting the inclusion of smaller trees in larger quadrats; this pattern was not present in two of the three second-growth stands. The dynamics of old-growth stands can provide a framework for interpreting patterns observed in second-growth stands. In an old-growth stand, the death of older, larger trees creates open patches allowing recruitment of juveniles. Patches of suitable size for recruitment were not present at the xeric second-growth stands. Proactive management of xeric second-growth stands by selective removal of small groups of overstory trees would allow a more uneven size distribution and would create open areas for recruitment. The flatwoods site differed from the xeric second-growth sites and thus is likely to require different management regimes.

Title:

A genetic linkage map of longleaf pine (Pinus palustris Mill.) based on random amplified polymorphic DNAs

Author:

Nelson, C. D.

Kubisiak, T. L.

Stine, M.

Nance, W. L.

Year published:

1994

Publication Type:

Peer-reviewed literature

Abstract:

Eight megagametophyte DNA samples from a single longleaf pine (Pinus palustris Mill.) tree were used to screen 576 oligonucleotide primers for random amplified polymorphic DNA (RAPD) fragments. Primers amplifying repeatable polymorphic fragments were further characterized within a sample of 72 megagametophytes from the same tree. Fragments segregating in a l:1, present-to-absent, ratio were classified as Mendelian markers and mapped using multipoint linkage analysis. The analysis revealed 16 linkage groups of at least three markers, ranging in size from 21.1 to 185.6 cM, and six linked pairs (5.5 to 23.0 cM) of markers. The 22 groups and pairs included 133 RAPD markers and covered approximately 1,635 cM of genetic map distance. Genome size estimates, based on the linkage data, ranged from 2,612 to 2,656 cM. Using a 30-cM map scale and including the 11 unlinked markers and the ends of the 16 linkage groups and six linked pairs, the set of RAPD markers accounts for approximately 2,265 cM, or 85% of the genome.

Title:

Longleaf pine patch dynamics influence ground-layer vegetation in old-growth pine savanna

Author:

Mugnani, M. P.

Robertson, K. M.

Miller, D. L.

Platt, W. J.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Old-growth longleaf pine savannas are characterized by diverse ground-layer plant communities comprised of graminoids, forbs, and woody plants. These communities co-exist with variable-aged patches containing similar-aged trees of longleaf pine (Pinus palustris Mill.). We tested the conceptual model that physical conditions related to the cycle of longleaf pine regeneration (stand structure, soil attributes, fire effects, and light) influence plant species’ composition and spatial heterogeneity of ground-layer vegetation. We used a chrono-sequence approach in which local patches represented six stages of the regeneration cycle, from open areas without trees (gaps) to trees several centuries old, based on a 40-year population study and increment cores of trees. We measured soil characteristics, patch stand structure, fuel loads and consumption during fires, plant productivity, and ground-layer plant species composition. Patch characteristics (e.g., tree density, basal diameter, soil carbon, and fire heat release) indicated a cyclical pattern that corresponded to the establishment, growth, and mortality of trees over a period of approximately three centuries. We found that plants in the families Fabaceae and Asteraceae and certain genera were significantly associated with a particular patch stage or ranges of patch stages, presumably responding to changes in physical conditions of patches over time. However, whole-community-level analyses did not indicate associations between the patch stage and distinct plant communities. Our study indicates that changes in composition and the structure of pine patches contribute to patterns in spatial and temporal heterogeneity in physical characteristics, fire regimes, and species composition of the ground-layer vegetation in old-growth pine savanna.

Title:

Intensive longleaf pine management for hurricane recovery: fourth-year results

Author:

Dyson, D. S.

Brockway, D. G.

Year published:

2015

Publication Type:

Proceedings

Abstract:

The frequency and intensity of hurricanes affecting the United States has been projected to increase during coming decades, and this rising level of cyclonic storm activity is expected to substantially damage southeastern forests. Although hurricane damage to forests in this region is not new, recent emphasis on longleaf pine (Pinus palustris Mill.) restoration and the increasing number of longleaf pine plantations resulting from such efforts raise questions about both tropical storm effects on this species and suitable strategies and practices for facilitating its recovery from such storms. This study was established to evaluate different methods of quickly returning damaged stands to productive longleaf pine forests following Hurricane Ivan in 2004. After salvage operations cleared the study areas, three herbicides (hexazinone, imazapyr, triclopyr) versus an untreated control were tested for their effects on stand development using artificially regenerated longleaf pine. A fertilizer treatment was also applied on half of the plots. Four years following planting, developing trends show the possible benefits of chemical site preparation on longleaf pine seedling height and ground-line diameter, whereas fertilization has shown no significant effect.

Title:

Fox squirrel and gray squirrel associations within minimally disturbed longleaf pine forests

Author:

Conner, L. M.

Landers, J. L.

Michener, W. K.

Year published:

1999

Publication Type:

Proceedings

Abstract:

Fox squirrels (Sciurus niger) are an important species in longleaf pine (Pinus palustris) forests. We estimated fox squirrel density within 6 minimally disturbed long- leaf pine strands, examined association between fox and gray squirrels (S. carolinensis), and measured habitat variables at fox and gray squirrel capture sites. Fox squirrel den- sity estimates ranged from 12-19 squirrels/km2 among study areas. Fox squirrel capture sites had higher pine basal area, higher total basal area, higher herbaceous groundcover, and lower woody groundcover than other sites. Gray squirrel capture sites had higher hardwood, oak, and total basal areas; lower pine basal area, higher woody groundcover, and less herbaceous groundcover than other sites. A strong negative association be- tween fox and gray squirrel capture sites appeared related to species-speci fic habitat preferences. Fox squirrel capture sites had higher pine and lower hardwood basal areas than gray squirrel capture sites. Further, herbaceous groundcover, especially wiregrass (Aristida stricta), dominated fox squirrel capture sites, whereas woody groundcover dominated gray squirrel capture sites. Logistic regression models indicated that pine basal area and herbaceous groundcover were positively related to probability of fox squirrel capture whereas fern groundcover was negatively related to the possibility of fox squirrel capture. Oak basal area and total basal area were positively related to prob- ability of gray squirrel capture whereas herbaceous groundcover was negatively related to possibility of gray squirrel capture. Oak basal area, total basal area, and herbaceous groundcover best discriminated between fox and gray squirrel capture sites. Prescribed fire retards hardwood enroachment, increases herbaceous groundcover, and thus may be critical to maintaining fox squirrel habitat.

Title:

Proceedings of the second montane longleaf conference/workshop

Author:

Cipollini, M. L.

Year published:

2006

Publication Type:

Proceedings

Title:

The effects of fire on nutrient cycles in longleaf pine ecosystems

Author:

Christensen, N. L.

Year published:

1993

Publication Type:

Proceedings

Title:

Using poultry litter to fertilize longleaf pine plantations for enhanced straw production

Author:

Chastain, J. P.

Rollins, P. A.

Riek, M.

Year published:

2007

Publication Type:

Proceedings

Abstract:

Longleaf pinestraw is high-quality landscape mulch that is in large demand in many urban and suburban areas of the Southeastern United States. In many cases, the annual income from pinestraw production is just as important to forestland owners as the value of the standing timber. A three-year study was conducted in an intensively managed longleaf pine plantation located in Kershaw County, SC. The purpose of the project was to compare the pinestraw production between unfertilized trees, trees fertilized with commercial fertilizer (17% N - 17% P2O5 - 17% K2O), and trees fertilized with poultry litter from a turkey grow-out barn. The commercial fertilizer and the poultry litter were applied so as to provide about 90 kg of plant available N (PAN) per hectare. The results of the study indicated that the enhancement of pinestraw production using granular fertilizer and turkey litter was similar. Providing a one-time application of 90 kg PAN/ha increased pinestraw production by 29% over the three-year study. The return on investment ranged from 968% for the granular fertilizer to 1590% for turkey litter. The advantages of using poultry litter were the greater persistence of plant available N and K in the soil, the addition of key minor plant nutrients, a small but sustained increase in soil pH, and a slight increase in cationic exchange capacity.

Title:

Potential product values from thinned longleaf pine plantations in Louisiana

Author:

Busby, R. L.

Thomas, C. E.

Lohrey, R. E.

Year published:

1993

Publication Type:

Proceedings

Abstract:

Investments in thinned longleaf pine (Pinus palustris Mill.) plantations are financially profitable based upon analysis of data gathered from Louisiana, Mississippi, and Texas. Site quality is a key determinate of results.

Title:

The best kept secret in southern forestry: longleaf pine plantation investments

Author:

Busby, R. L.

Thomas, C. E.

Lohrey, R. E.

Publication Type:

Proceedings

Abstract:

The objective of this study was to determine the potential harvest value of thinned longleaf pine (Pinus palustris Mill.) plantations. Longleaf has long been recognized as having reduced risk of rust and bark beetle attack compared to other species. Because of the development of new techniques that speed longleaf’s transition through the grass stage, establishing longleaf pine plantations is becoming more attractive. Analyses were done on a subset of an existing spacing and thinning study in longleaf plantations. Land expectation values were computed on the basis of current product prices, assumptions employing more than 2,000 individual trees, and a dynamic programming solution to economic conditions. Both the biological and financial results point to rotations of more than 40 years for longleaf. This information will provide assistance for decision-makers considering establishing longleaf pine plantations.

Title:

An updated whole stand growth and yield system for planted longleaf pine in southwest Georgia

Author:

Brooks. J. R.

Jack, S. B.

Year published:

2016

Publication Type:

Proceedings

Abstract:

An updated whole stand growth and yield system for planted longleaf pine (Pinus palustris) was developed from permanent plot data collected annually over a 13 to 16 year period. The data set consists of 15 intensively managed longleaf pine plantations that are located in Lee, Worth, Mitchell, and Baker counties in southwest Georgia. Stand survival, dominant height, basal area and cubic foot volume yield models were developed for both low and high planting densities. Model prediction error remained low for both planting density classes. Yield models are an improvement over those published in 2006 (Brooks and Jack, 2006), as eight additional growth remeasurements were added which improved projection accuracy for stands older than 10 years. Models are designed for application in unthinned stands (prior to onset of self thinning) in this region between stand age 2 and 25 years.

Title:

Long-term changes in flowering and cone production by longleaf pine

Author:

Boyer, W. D.

Year published:

1998

Publication Type:

Proceedings

Abstract:

Cone production by longleaf pine has been followed for up to 30 years in regeneration areas at five to nine coastal plain sites from North Carolina to Louisiana. A rapid increase in the size and frequency of cone crops has occurred since 1986 following 20 years of relative stability. Cone production for the last 10 years averaged 36 cones per tree versus 14 cones per tree for the preceding 20 years. This change was evident at most sites, including the Escambia Experimental Forest where longleaf pollen shed has been recorded since 1957 and counts of female flowers in regeneration areas since 1970. Although pollen production was cyclic, no long-term change was evident. The recent increase in cone production seems due to both an increase in flower production and an increase in the fraction of flowers surviving to become mature cones.

Title:

Eighteen years of seasonal burning in longleaf pine: effects on overstory growth

Author:

Boyer, W. D.

Year published:

1993

Publication Type:

Proceedings

Abstract:

The effects of several hardwood control treatments on understory succession and overstory growth have been followed for 19 years on a Coastal Plain site in southwest Alabama. The study began in 1973, with 12 treatment combinations in 14-year-old naturally established longleaf pine (Pinus palustris Mill.) thinned to about 500 stems/acre. Four burning treatments, namely biennial burns in winter, spring, and summer plus an unburned check were each combined with three supplemental hardwood control treatments: an initial chemical injection of all hardwoods, periodic cutting of all woody stems, and no treatment. Pine stands were thinned to 70 ft2 basal area/acre in 1990. All measures of pine growth were significantly reduced by burning. By 1992, the volume yield of 3,222 ft3/acre on unburned plots significantly exceeded the average yield of 2,606 ft3/acre for the three burning treatmeats, which did not differ significantly among themselves. The significant effect of fire on pine diameter and height growth did not extend beyond age 24, although effects on basal area and volume growth have continued to age 30. Supplemental treatments have not yet affected pine volume growth.

Title:

Annual and geographic variations in cone production by longleaf pine

Author:

Boyer, W. D.

Year published:

1986

Publication Type:

Proceedings

Abstract:

Cone production by longleaf pine (Pinus palustris Mill.) has been monitored on sample trees in shelterwood stands since 1966. Eleven locations, three each in Alabama and Florida and one in Louisiana, Mississippi, Georgia, South Carolina, and North Carolina were included in the study. Each location had two test areas, with 50 sample trees each. Six locations had 15 or more years of record, the others less. Annual counts of cones, conelets, and flowers (pistillate strobili) on each sample tree were made until trees were cut. Over 20 years, cone crops in which the average number of cones per tree exceeded 50 occurred only in 1967, 1973, and 1984. The frequency of cone crops potentially useable for natural regeneration (average of 20 or more cones/tree) varied considerably among locations. Cone crop frequency was very low (< 0.1 or 1 year in 10) at two locations in northwest Florida and one in southwest Georgia. Cone crop frequency reached a peak of 0.62 and 0.75 at two locations in central Alabama. The ratio of flowers counted to cones produced suggests that low cone crop frequencies near the Gulf Coast were due more to flower losses than failure to produce flowers.

Title:

Guidelines for estimating cone and seed yields of southern pines

Author:

Barnett, J. P.

Year published:

1999

Publication Type:

Proceedings

Abstract:

Our ability to predict cone and seed yields of southern pines (Pinus spp.) prior to collection is important when scheduling and allocating resources. Many managers have enough historical data to predict their orchards' yield; but such data are generally unavailable for some species and for collections outside of orchards. Guidelines are presented to allow prediction of cones per tree, to convert numbers of cones to bushels, to estimate numbers of seeds per cone, and to convert numbers of seeds per bushel to pounds of seeds per bushel. Once we have these data, crop prediction is a straightforward process.

Title:

Presettlement fire regime and vegetation mapping in the southeastern coastal plain forest ecosystems

Author:

Bailey, A. D.

Mickler, R.

Frost, C.

Year published:

2007

Publication Type:

Proceedings

Abstract:

Fire-adapted forest ecosystems make up 95 percent of the historic Coastal Plain vegetation types in the Southeastern United States. Fire suppression over the last century has altered the species composition of these ecosystems, increased fuel loads, and increased wildfire risk. Prescribed fire is one management tool used to reduce fuel loading and restore fire-adapted species, but little information exists on the presettlement extent and location of fire-dependent ecosystems at a level of detail useful to guide land management decisions at the local spatial scale. In an effort to close this knowledge gap, the principles of landscape fire ecology have been applied to develop a detailed presettlement fire regime map for ~200,000 acres of Coastal Plain ecosystems. Factors evaluated include the effects of fire compartment size in the original landscape, fire barriers, fire filters, prevailing wind direction during fire season, topographic and soil factors affecting fire intensity, fire frequency, fire spread, and fire effects on vegetation. The fire regime map was then combined with remnant fire-adapted vegetation surveys, historic aerial photography, digital elevation models, and soil survey information to create a map of presettlement vegetation. This map is being used to develop prescribed burning plans that restore original fire regimes, guide the use of prescribed fire as a management tool, restore fire-adapted vegetation structure and understory species diversity for threatened and endangered species, and enhance ecosystem sustainability.

Title:

Ecology of root-feeding beetles and their associated fungi on longleaf pine in Georgia

Author:

Zanzot, J. W.

Matusick, G.

Eckhardt, L. G.

Year published:

2010

Publication Type:

Peer-reviewed literature

Abstract:

Root-feeding beetles, particularly of the curculionid subfamilies Scolytinae and Molytinae, are known to be effective vectors of Ophiostomatoid fungi. Infestation by these insects and subsequent infection by the Ophiostomatoid fungi may play an important role in accelerating symptom progression in pine declines. To examine the relationship between beetles and fungi in longleaf pine stands, root-feeding curculionids were collected in pitfall traps baited with ethanol and turpentine for 62 wk, and Ophiostomatoid fungi were isolated from their body surfaces. The most abundant root-feeding beetles captured were Hylastes tenuis, H. salebrosus, Pachylobius picivorus, Hylobius pales, and Dendroctonus terebrans. The number of insects captured peaked in spring and fall, although peaks for different insect taxa did not coincide. The most frequently isolated fungi were Grosmannia huntii, Leptographium procerum, L. terebrantis, and L. serpens. Other Ophiostomatoid fungi recovered included Ophiostoma spp. and Pesotum spp. Insect infestation data suggest that Hylastes spp. share an ecological niche, as do Hb. pales and P. picivorus, because the ratios of their fungal symbionts were similar. The fungi associated with D. terebrans suggest that it did not share habitat with the other principle vectors.

Title:

The impact of Hurricane Michael on longleaf pine habitats in Florida

Author:

Zampieri, N. E.

Pau, S.

Okamoto, D. K.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Global biodiversity hotspots (GBHs) are increasingly vulnerable to human stressors such as anthropogenic climate change, which will alter the ecology of these habitats, even where protected. The longleaf pine (Pinus palustris) ecosystem (LPE) of the North American Coastal Plain is a GBH where disturbances are integral for ecosystem maintenance. However, stronger storms due to climate change may be outside their historical norm. In this study, we estimate the extent of Florida LPE that was directly affected by Hurricane Michael in 2018, an unprecedented Category 5 storm. We then leveraged a unique data set in a Before-After study of four sites within this region. We used variable-area transects and generalized linear mixed-effects models to estimate tree densities and logistic regression to estimate mortality by size class. We found at least 28% of the global total remaining extent of LPE was affected in Florida alone. Mortality was highest in medium sized trees (30–45 cm dbh) and ranged from 4.6–15.4% at sites further from the storm center, but increased to 87.8% near the storm center. As the frequency and intensity of extreme events increases, management plans to mitigate climate change need to account for large-scale stochastic mortality events to preserve critical habitats.

Title:

Time-since-fire and stand seral stage affect habitat selection of eastern wild turkeys in a managed longleaf pine ecosystem

Author:

Wood, J. W.

Cohen, B. S.

Prebyl, T. J.

Conner, L. M.

Collier, B. A.

Chamberlain, M. J.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine (Pinus palustris) forests rely on prescribed fire to limit encroachment of hardwoods and maintain early successional understory communities. However, prescribed fire may alter habitat availability while female eastern wild turkeys (Meleagris gallopavo silvestris) are reproductively active. In addition, the vigor of vegetation regrowth post-fire is impacted by both midstory and overstory stand-conditions which can be a function of stand age. Therefore, the degree to which prescribed fire affects habitat availability and selection of wild turkeys may be a function of both time-since-fire and the age of the stand fire was applied to. We assessed habitat selection of female wild turkeys during their reproductive cycle in a longleaf pine forest managed with frequent prescribed fire. We captured 63 female wild turkeys during 2015 and 2016 on a longleaf pine-dominated landscape in southwestern Georgia, USA, that was managed with 1–3 year fire-return intervals applied to relatively small burn blocks (mean size of burn=26.02 ha in 2015; 19.84 ha in 2016) on pine stands of varying age-classes. We attached Global Positioning Systems units to individuals and collected hourly locations from 1 March to 15 August. We then used distance-based analyses to estimate daily selection or avoidance of vegetation communities relative to the known reproductive phenology of individual females. Females selected hardwood stands during pre-nesting and post-nesting phases, but avoided them during the incubation phase. Females used open vegetation communities during all phases of reproduction following pre-nesting. Turkeys selected areas burned ≤2 years prior but used different seral stages of pine during different reproductive phases. Specifically, females selected for recently burned mature pine stands during incubation but then selected for recently burned young pine stands, mature pine stands burned 2 years earlier, and open vegetation communities during brooding. Our findings demonstrate that time-since-fire and stand seral age interact to affect how turkeys use pyric landscapes. In general, pine stands providing ample understory vegetation are favored while females are reproductively active. Our data suggests practitioners should try to manage a landscape containing both young and mature pine stands and use prescribed fire to create understory conditions selected by turkeys across all reproductive phases.

Title:

Infiltration and runoff water quality response to silvicultural and grazing treatments on a longleaf pine forest

Author:

Wood, J. C.

Blackburn, W. H.

Pearson, H. A.

Hunter, T. K.

Year published:

1989

Publication Type:

Peer-reviewed literature

Abstract:

The impacts of intensive vs. extensive silviculture, and moderate continuous livestock grazing vs. no livestock grazing as they relate to infiltration and runoff water quality were evaluated using rainfall simulation. Study sites were located in the Vernon District of the Kisatchie National Forest, Louisiana. Infiltration was greater, and interrill erosion, suspension-solution phase total nitrogen concentrations, and suspension-solution phase total phosphate concentrations were less from areas under extensive silviculture and no livestock grazing than from areas under intensive silviculture and livestock grazing, respectively. Intensive silviculture exposed more bare soil than extensive treatments. Litter cover and litter biomass were significantly reduced by the intensive silvicultural treatment. Livestock grazing also exposed more bare soil mainly resulting from a removal of grass cover and biomass.

Title:

Timber thinning and prescribed burning as methods to increase herbage on grazed and protected longleaf pine ranges

Author:

Wolters, G. L.

Year published:

1981

Publication Type:

Peer-reviewed literature

Abstract:

Selective commercial timber thinning and prescribed burning are effective tools in maintaining a productive forage resource on stocked range of longleaf pine (Pinus palustris). Productive mixtures of herbaceous species can be sustained through periodic timber thinning to maintain 12 to 20 m2/ha of longleaf pine basal area and rotational winter burning, at 3-year intervals. Two to three years of heavy use can be expected after patch cutting if the area of patch cuts constitute a minor percentage of the total grazed range unit. Heavy use may convert patch cuts predominantly to carpetgrass and forested range to a mixture of forbs. Pine plantations throughout the South can be managed for concurrent production of wood fiber and forage (Pearson et al. 1971, Grelen and Enghardt 1973, and Hart et al. 1970). With proper management, continuous grazing by cattle is not detrimental to establishing and growing artificially regenerated pine plantations (Pearson et al. 1971), nor is forage production seriously diminished by pine canopies until plantations approach 10 years of age (Wolters 1973). Many longleaf pine (Pinus palustris) plantations are rapidly approaching or have already attained commercial timber size and could be thinned to generate immediate cash income. Observations and available literature suggest that selective tree removal or patch cutting within a plantation drastically alters forage production and livestock utilization patterns; thus, the current study was started to determine what effects the rate of tree removal had on concurrent forage production, its botanical composition, and utilization by cattle when the range was burned by controlled backfire every third year. Findings will facilitate development of guidelines to integrate management of timber and forage on longleaf pine ranges.

Title:

Reproductive consequences of habitat fragmentation for a declining resident bird of the longleaf pine ecosystem

Author:

Winiarski, J. M.

Moorman, C. E.

Carpenter, J. P.

Hess, G. R.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Habitat loss and fragmentation are major threats to bird population persistence. Yet, our understanding of the demographic factors behind the adverse effects of fragmentation remains limited for many species. We studied the breeding demographics of the Bachman’s Sparrow (Peucaea aestivalis), a species of conservation concern that is associated with highly imperiled longleaf pine ecosystems in the southeastern United States. We quantified the effects of local- and landscape-scale factors on different components of reproductive success (i.e., pairing success and probability of fledging offspring) for 96 male sparrows at eight sites in southeastern North Carolina. Pairing success of monitored sparrows was 69%, and 77% of paired males fledged ≥1 offspring. Habitat amount in the surrounding landscape, rather than local habitat quality, was the most influential predictor of pairing success for male Bachman’s Sparrows. In contrast, we documented no predictors of successfully fledging offspring for paired males. We infer that reduced pairing success is limiting reproduction in isolated landscapes and may be a contributing factor for the low occupancy and declines of Bachman’s Sparrow in our study region. Overall, our results suggest that managers can promote breeding opportunities for Bachman’s Sparrows by prioritizing resources to patches near large, preexisting longleaf pine forest to ensure ≥20% habitat within the surrounding landscape.

Title:

Nest-site selection and nest survival of Bachman’s sparrows in two longleaf pine communities

Author:

Winiarski, J. M.

Fish, A. C.

Moorman, C. E.

Carpenter, J. P.

DePerno, C. S.

Schillaci, J. M.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine (Pinus palustris) ecosystems of the southeastern United States have experienced high rates of habitat loss and fragmentation, coinciding with dramatic population declines of a variety of taxa that inhabit the system. The Bachman’s Sparrow (Peucaea aestivalis), a species closely associated with fire-maintained longleaf pine communities, is listed as a species of conservation concern across its entire range. Bachman’s Sparrow breeding biology may provide valuable insights into population declines and inform restoration and management of remnant longleaf pine forest, but the species’ secretive nesting habits have received little attention. We located 132 Bachman’s Sparrow nests in the Coastal Plain and Sandhills physiographic regions of North Carolina, USA, during 2014–2015, and modeled nest-site selection and nest survival as a function of vegetation characteristics, burn history, temporal factors, and landscape level habitat amount. There were distinct differences in nest-site selection between regions, with Bachman’s Sparrows in the Coastal Plain region selecting greater woody vegetation density and lower grass density at nest sites than at non-nest locations. In contrast, sparrows selected nest sites with intermediate grass density and higher tree basal area in the Sandhills region. Despite clear patterns of nest-site selection, we detected no predictors of nest survival in the Sandhills, and nest survival varied only with date in the Coastal Plain. Daily survival rates were similar between regions, and were consistent with published studies from the species’ core range where declines are less severe. Overall, our results indicate that creating and maintaining community-specific vegetation characteristics through the application of frequent prescribed fire should increase the amount of nesting cover for Bachman’s Sparrows.

Title:

Seed depredation negates the benefits of midstory hardwood removal on longleaf pine seedling establishment

Author:

Willis, J. L.

Schnake, D. K.

Wetzstein, B.

Yow, J.

Guinto, D.

Ulrich, S.

DePerno, C. S.

Lashley, M. A.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Midstory hardwoods are traditionally removed to restore longleaf pine on fire-excluded savannas. However, recent evidence demonstrating midstory hardwood facilitation on longleaf pine seedling survival has brought this practice into question on xeric sites. Also, midstory hardwoods could facilitate longleaf pine seedling establishment, as hardwood litter may conceal seeds from seed predators or improve micro-environmental conditions for seedling establishment. However, little is known about these potential mechanisms. In this study, we tracked longleaf pine seed depredation and germination in artificially seeded plots (11 seeds/m2) in a factorial design fully crossing hardwood retention or removal with vertebrate seed predator access or exclusion in the Sandhills Ecoregion of North Carolina, U.S.A. Seed depredation averaged 78% across treatments and was greatest in unexcluded plots. Hardwood retention did not affect seed depredation. Longleaf pine averaged 3.6 germinants/4m2 across treatments, and was six times more abundant where vertebrates had been excluded. Hardwood removal had a strong positive effect on seedling germination, likely due to the removal of litter, but only when vertebrates were excluded. Our results indicatedmidstory hardwoods are not facilitating longleaf pine seedling establishment. Nevertheless, our results indicated that hardwood removal may not increase longleaf pine seedling establishment, as seed depredation diminished the effectiveness of hardwood removal under mast seed availability. Collectively, these results demonstrate the underlying complexity of the longleaf pine ecosystem, and suggest that planting may need to be part of the restoration strategy on sites where seed depredation limits longleaf pine natural regeneration.

Title:

Influence of roller chopping and prescribed burning on insects in pine flatwoods

Author:

Willcox, E. V.

Giuliano, W. M.

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

Roller chopping and prescribed burning are treatments frequently applied to many southeastern rangeland systems, including Florida's pine flatwoods. These treatments can improve rangeland condition by reducing the cover of shrubs and promoting the growth of herbaceous species. How- ever, they have the potential to both positively and negatively affect insects, which provide important ecosystem services as pollinators and are a food source for numerous rangeland-associated avian species, some of which are of conservation concern. We compared total insect familial richness and relative abundance, and familial richness and relative abundance within five orders that contain insects important as pollinators and avian prey (i.e., Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, and Orthoptera) at sampling sites randomly located within 50 treated (i.e., dormant sea- son burn, growing season burn, dormant season roller chop, growing season roller chop, or roller chop/burn combination) and untreated (i.e., control) subplots in central and southern Florida during 2007 and 2008. Total relative abundance (P=0.017) and Hemiptera familial richness (P=0.021) and relative abundance (P = 0.002) were less in growing season burn compared to control subplots for two years post-treatment. Reductions in total insect familial richness were also observed in growing season burn compared to control subplots but only lasted for one year post-treatment (P = 0.017). Total insect familial richness (P ≤ 0.001) and relative abundance (P = 0.001), as well as familial richness and relative abundance of Diptera, Hemiptera, Hyme- noptera, or Orthoptera were also less on dormant season burn than control subplots the first-year post treatment (P ≤ 0.028). Total insect familial rich- ness (P = 0.017) and relative abundance (P = 0.032) were less in dormant season roller chop compared to control subplots for two years post-treatment, as was Hemiptera relative abundance (P = 0.052). In situations where management of certain insect orders important as pollinators and avian prey is a priority, the use of growing season roller chopping and dormant season burning may be preferred over dormant season roller chopping and growing season burning.

Title:

Seasonal effects of prescribed burning and roller chopping on saw palmetto in flatwoods

Author:

Willcox, E. V.

Giuliano, W. M.

Year published:

2010

Publication Type:

Peer-reviewed literature

Abstract:

Shrub encroachment has become a problem in many rangeland systems across the United States due to a reduction in the disturbances, primarily fire, which historically maintained them. The shrub saw palmetto (Serenoa repens) has become abundant in many habitats of the southeastern Coastal Plain, including Florida. When fire regimes are altered or fires are suppressed, this species can proliferate leading to significant changes in the ecosystem, particularly the herbaceous vegetation. Prescribed burning and roller chopping are management activities often used to control saw palmetto. However, little is known about the effects these treatments have on this shrub, particularly when applied in different seasons. We compared the seasonal effects of prescribed burning, roller chopping, and combinations of the two on saw palmetto. The effects of treatments on saw palmetto were assessed using a paired-sample approach, where saw palmetto height, cover, and density were compared between sampling locations randomly located within treated (e.g., burned) and untreated areas. Dormant season burning had no effect on saw palmetto density and height and only temporarily reduced cover, with rapid regrowth occurring the first year post-treatment. Growing season burning also had no effect on saw palmetto density. However, saw palmetto cover was lower on growing season burn compared to control sites the first year post-treatment and height the first and second year post-treatment. The combination of burning and roller chopping, despite having no effect on saw palmetto density, did result in lower saw palmetto height compared to controls the first and second year post-treatment. The effect of roller chopping/burning on saw palmetto cover depended on season and year. Saw palmetto cover and height were lower on dormant and growing season roller chop than control sites the first and second year post-treatment, but only growing season roller chopping had an effect on saw palmetto density. The single application of a dormant or growing season burn is not recommended for control of high-density saw palmetto, however, it may be suitable to maintain areas where saw palmetto levels are low and proliferation of the species is not a threat. Dormant and growing season roller chopping showed the greatest potential for rapid saw palmetto control. Growing season roller chopping is recommended if significant reductions in saw palmetto density are desired.

Title:

Seed heat tolerance and germination of six legume species native to a fire-prone longleaf pine forest

Author:

Wiggers, M. S.

Hiers, J. K.

Barnett, A.

Boyd, R. S.

Kirkman, L. K.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Recognition of spatial heterogeneity of fire at fine scales is emerging, particularly in ecosystems characterized by frequent, low-intensity fire regimes. Differences in heat flux associated with variation in fuel and moisture conditions create microsites that affect survivorship and establishment of species. We studied the mechanisms by which fire affects seed germination using exposure of seeds to fire surrogates (moist and dry heat). Tolerance (survival) and germination responses of six perennial, herbaceous legume species common to the fire-prone longleaf pine–wiregrass ecosystem of the southeastern USA were examined the following heat treatments.Moist heat wasmore effective in stimulating germination than dry heat flux for most species examined. We also compared intrinsic seed properties (relative seed coat hardness, percent moisture, and seed mass) among species relative to their heat tolerance and heat-stimulated germination responses. Seed coat hardness was closely associated with the probability of dry and moist heat-stimulated germination. Variation among species in optimal germination conditions and degree of heat tolerance likely reflects selection for specific microsites among a potentially diverse suite of conditions associated with a low-intensity fire regime. Fire-stimulated germination, coupled with characteristics of seed dormancy and longevity in the soil, likely fosters favorable recruitment opportunities in restoration situations aimed at reintroducing a frequently prescribed burn regime to a relict longleaf pine site. In a restoration context in which externally available seed pool inputs are limited, this regenerative mechanism may provide a significant source of recruitment for vegetative recovery in a post-fire landscape.

Title:

Quantifying energy use efficiencey via entropy production: a case study from longleaf pine ecosystems

Author:

Wiesner, S.

Staudhammer, C. L.

Stoy, P. C .

Boring, L. R.

Starr, G.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Ecosystems are open systems that exchange matter and energy with their environment. They differ in their efficiency in doing so as a result of their location on Earth, structure and disturbance, including anthropogenic legacy. Entropy has been proposed to be an effective metric to describe these differences as it relates energy use efficiencies of ecosystems to their thermodynamic environment (i.e., temperature) but has rarely been studied to understand how ecosystems with different disturbance legacies respond when confronted with environmental variability. We studied three sites in a longleaf pine ecosystem with varying levels of anthropogenic legacy and plant functional diversity, all of which were exposed to extreme drought. We quantified radiative (effrad), metabolic and overall entropy changes – as well as changes in exported to imported entropy (effflux) in response to drought disturbance and environmental variability using 24 total years of eddy covariance data (8 years per site). We show that structural and functional characteristics contribute to differences in energy use efficiencies at the three study sites. Our results demonstrate that ecosystem function during drought is modulated by decreased absorbed solar energy and variation in the partitioning of energy and entropy exports owing to differences in site enhanced vegetation index and/or soil water content. Low effrad and metabolic entropy as well as slow adjustment of efflux at the anthropogenically altered site prolonged its recovery from drought by approximately 1 year. In contrast, stands with greater plant functional diversity (i.e., the ones that included both C3 and C4 species) adjusted their entropy exports when faced with drought, which accelerated their recovery. Our study provides a path forward for using entropy to determine ecosystem function across different global ecosystems.

Title:

The role of understory phenology and productivity in the carbon dynamics of longleaf pine savannas

Author:

Wiesner, S.

Staudhammer, C. L.

Javaheri, C. L.

Hiers, J. K.

Boring, L. R.

Mitchell, R. J.

Starr, G.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Savanna ecosystems contribute ~30% of global net primary production (NPP), but they vary substantially in composition and function, specifically in the understory, which can result in complex responses to environmental fluctuations. We tested how understory phenology and its contribution to ecosystem productivity within a longleaf pine ecosystem varied at two ends of a soil moisture gradient (mesic and xeric). We used the Normalized Difference Vegetation Index (NDVI) of the understory and ecosystem productivity estimates from eddy covariance systems to understand how variation in the understory affected overall ecosystem recovery from disturbances (drought and fire). We found that the mesic site recovered more rapidly from the disturbance of fire, compared to the xeric site, indicated by a faster increase in NDVI. During drought, understory NDVI at the xeric site decreased less compared to the mesic site, suggesting adaptation to lower soil moisture conditions. Our results also show large variation within savanna ecosystems in the contribution of the understory to ecosystem productivity and recovery, highlighting the critical need to further subcategorize global savanna ecosystems by their structural features, to accurately predict their contribution to global estimates of NPP.

Title:

Approximating nature’s variation: selecting and using reference information in restoration ecology

Author:

White, P. S.

Walker, J. L.

Year published:

1997

Publication Type:

Peer-reviewed literature

Abstract:

Restoration ecologists use reference information to define restoration goals, determine the restoration potential of sites, and evaluate the success of restoration efforts. Basic to the selection and use of reference information is the need to understand temporal and spatial variation in nature. This is a challenging task: variation is likely to be scale dependent; ecosystems vary in complex ways at several spatial and temporal scales; and there is an important interaction between spatial and temporal variation. The two most common forms of reference information are historical data from the site to be restored and contemporary data from reference sites (sites chosen as good analogs of the site to be restored). Among the problems of historical data are unmeasured factors that confound the interpretation of historical changes observed. Among the problems of individual reference sites is the difficulty of finding of proving a close match in all relevant ecological dimensions. Approximating and understanding ecological variation will require multiple sources of information. Restoration, by its inherently experimental nature, can further the understanding of the distribution, causes, and functions of nature’s variation.

Title:

Historical fire in longleaf pine (Pinus palustris) forests of south Mississippi and its relation to land use and climate

Author:

White, C. R.

Harley, G. L.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

We characterized historical fire regimes in Pinus palustris (longleaf pine) forests of southern Mississippi with regard to global and regional coupled climate systems (e.g., El Niño–Southern Oscillation) and past human activity. The composite fire chronology spanned 1756–2013 with 132 individual scars representing 89 separate fire events. The mean fire interval was 2.9 yr, and mean intervals were significantly different between identified time periods (e.g., settlement period vs. management period). Evidence of biannual fire activity (up to three fires occurring within a 12-to 15-month period) was found coeval with a peak in livestock grazing and logging from the 1850s through the 1880s. Connections were also found between historical fire and Pacific climate variability (e.g., El Niño–Southern Oscillation and Pacific Decadal Oscillation; P < 0.05), yet the fire–climate linkage was likely at least partially masked by substantial human land use activities over the past several centuries. Coupled climate and human land use activity controlled the historical fire regime over the past ca. 240 yr. Although the many fire adaptions of P. palustris yield limitations in tree-ring- based fire history studies (e.g., thick bark), we highlight the efficacy of considering the height at which fire scars are analyzed along the bole as a way to glean a more accurate depiction of historical fire occurrence, especially in ecosystems characterized by a frequent, low-severity fire regime. This study suggests growing-season fire prescribed at a 2-to 3-yr interval would be the first step toward simulating historical landscape conditions and fire activity, should that be the goal by land managers.

Title:

Fire season, overstoy density and groundcover composition affect understory hardwood sprout demography in longleaf pine woodlands

Author:

Whelan, A. W.

Bigelow, S. W.

Nieminen, M. F.

Jack, S. B.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Seasonal timing of prescribed fire and alterations to the structure and composition of fuels in savannas and woodlands can release understory hardwoods, potentially resulting in a global increase of closed-canopy forest and a loss of biodiversity. We hypothesized that growing-season fire, high overstory density, and wiregrass presence in longleaf pine woodlands would reduce the number and stature of understory hardwoods, and that because evergreen hardwoods retain live leaves, dormant-season fire would reduce performance and survival of evergreen more than deciduous hardwoods. Understory hardwood survival and height were monitored over seven years in longleaf pine woodlands in southwest Georgia with a range of overstory density, groundcover composition, and season of application of prescribed fire. Hardwood stem survival decreased with increasing overstory density, and deciduous hardwoods were more abundant in the absence of wiregrass. Contrary to expectations, evergreen hardwood growth increased following dormant-season fire. Differences in hardwood stem survival and height suggest that low fire intensity in areas with low overstory density increase the risk that hardwoods will grow out of the understory. These results indicate a need for focused research into the effects of groundcover composition on hardwood stem dynamics and emphasize that adequate overstory density is important in longleaf ecosystem management.

Title:

Aligning endangered species managemnet with fire-dependent ecosystem restoration: manager perspectives on red-cockaded woodpecker and longleaf pine management actions

Author:

Weiss, S. A.

Toman, E. L.

Corace, R. G.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Background: Endangered species management has been criticized as emphasizing a single-species approach to conservation and, in some cases, diverting resources from broad-based, land management objectives important for overall biodiversity maintenance. Herein we examine perceptions on management for an endangered species whose habitat requirements largely depend on frequent fire, the red-cockaded woodpecker (Leuconotopicus borealis Vieillot). In doing so, we consider the alignment between species-specific population recovery actions and broader ecosystem restoration goals. Through semi-structured interviews with natural resource professionals (n = 32) in the Southeast Coastal Plain of the United States, we examined manager perspectives on the evolution of recovery efforts and the potential alignment of recovery efforts with other management goals and objectives on public lands. Results: Participants described an evolution of approaches to manage red-cockaded woodpeckers, from an initial emphasis on intensive management actions with a single-species focus to reduce extinction risk (e.g., artificial inserts and translocation of individual birds) to a broader focus on restoring forest conditions and the processes that maintain them (e.g., fire). Most participants considered red-cockaded woodpecker habitat management to be compatible with other resource management actions (e.g., prescribed fire, mechanical thinning). However, there were some notable exceptions as a smaller but substantive number of participants indicated that specific habitat management guidelines (basal area guidelines for foraging habitat) posed a barrier to implementing preferred ecosystem restoration actions (transitioning stands of fast-growing, short-lived pines to longleaf pine [Pinus palustris Mill.]). Overall, participants expected efforts to provide habitat for red-cockaded woodpeckers to continue regardless of its conservation status and that intensive, single-species management actions would likely decrease over time. Conclusions: Providing for the specific needs of specialist species that are in decline is often necessary to prevent their extinction in the near term. Our findings suggest that the ability to connect long-term management actions to recover endangered species to other agency priorities may promote the willingness of managers to prioritize and continue long-term management of their habitats.

Title:

Burned to be wild: Herbert Stoddard and the roots of ecological conservation in the southern longleaf pine forest

Author:

Way, A. G.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

This essay examines the work of wildlife biologist Herbert Stoddard, who came to the longleaf pine-grassland forests of south Georgia in 1924 to study the bobwhite quail, and stayed to develop a method of land management that stressed ecological habitat over the dominant production-oriented model. Stoddard's major early accomplishments were threefold: He helped to create the new profession of wildlife management, he fought for the reintroduction of fire in the longleaf-grassland system, and he was among the first to advocate for ecological diversity in cultural landscapes. His work offers new insight on how conservation played out regionally, suggesting that we rethink the local elements of national conservation policy.

Title:

Multivariate modelling of density, strength and stiffness from near infrared spectra for mature, juvenile and pith wood of longleaf pine (Pinus palustris)

Author:

Via, B. K.

Shupe, T. F.

Groom, L. H.

Stine, M.

So, C.

Year published:

2003

Publication Type:

Peer-reviewed literature

Abstract:

In manufacturing, monitoring the mechanical properties of wood with near infrared spectroscopy (NIR) is an attractive alternative to more conventional methods. However, no attention has been given to see if models differ between juvenile and mature wood. Additionally, it would be convenient if multiple linear regression (MLR) could perform well in the place of more complicated multivariate models. Therefore, the purpose of this paper was to model the strength, stiffness and density of mature and juvenile longleaf pine to NIR spectra with MLR and principal component regression (PCR).

Title:

Post-fire tree stress and growth following smoldering duff firesPost-fire tree stress and growth following smoldering duff fires

Author:

Varner, J. M.

Putz, F. E.

O'Brien, J. J.

Hiers, J. K.

Mitchell, R. J.

Gordon, D. R.

Year published:

2009

Publication Type:

Peer-reviewed literature

Abstract:

Understanding the proximate causes of post-fire conifer mortality due to smoldering duff fires is essential to the restoration and management of coniferous forests throughout North America. To better understand duff fire-caused mortality, we investigated tree stress and radial growth following experimental fires in a long-unburned forest on deep sands in northern Florida, USA. We burned basal fuels surrounding 80 mature Pinus palustris Mill. in a randomized experiment comparing the effects of basal burning treatments on stem vascularmeristems; surficial roots; root and stem combinations; and a non-smoldering control. We examined the effects of duration of lethal temperatures (>60 8C) on subsequent pine radial growth and root non-structural carbohydrates (starch and sugar). Duff and mineral soil temperatures in the experimental fires consistently exceeded 60 8C for over an hour following ignition, with lethal temperatures of shorter duration recorded 20 cm below the mineral soil surface. Duff heating was best explained by day-of-burn Oe horizon moisture (P = 0.01), although little variation was explained (R2 = 0.24). Post-fire changes in latewood radial increment in the year following fires was related to duration of temperatures >60 8C 10 cm deep in the mineral soil (P = 0.07), but explained little variability in post-fire growth (R2 = 0.17). In contrast, changes in non-structural carbohydrate content in coarse roots (2–5 mm diameter) 120 days following burning were more strongly correlated with the duration of lethal heating 5 cm below the mineral soil surface (P = 0.02; R2 = 0.53). Results from this study implicate the role of mineral soil heating in the post-fire decline of mature longleaf pine following restoration fires in sandy soils.

Title:

Overstory tree mortality resulting from reintroducing fire to long-unburned longleaf pine forests: the importance of duff moisture

Author:

Varner, J. M.

Hiers, J. K.

Ottmar, R. D.

Gordon, D. R.

Putz, F. E.

Wade, D. D.

Year published:

2007

Publication Type:

Peer-reviewed literature

Abstract:

In forests historically maintained by frequent fire, reintroducing fire after decades of exclusion often causes widespread overstory mortality. To better understand this phenomenon. we subjected 16 fire-excluded (ca. 40 years since fire) 10-ha longleaf pine (Pinus palustris Mill.) stands to one of four replicated burning treatments based on volumetric duff moisture content (VDMC): wet (115 percent VDMC): moist (85 percent VDMC); dry (55 percent VDMC); and a no-burn control. During the first 2 years postfire, overstory pines in the dry burns suffered the greatest mortality (mean 20.5 percent); pine mortality in the wet and moist treatments did not differ from the control treatment. Duff reduction was greatest in the dry burns (mean 46.5 percent), with minimal reduction in the moist and wet burns (14.5 and 5 percent, respectively). Nested logistic regression using trees from all treatments revealed that the best predictors of individual pine mortality were duff consumption and crown scorch (P < 0.001; R2 = 0.34). Crown scorch was significant only in dry burns, whereas duff consumption was significant across all treatments. Duff consumption was related to moisture content in lower duff (Oa; R2 = 0.78, P < 0.001). Restoring fire to long-unburned forests will require development of burn prescriptions that include the effects of duff consumption, an often overlooked fire effect.

Title:

Restoring fire to long-unburned Pinus palustris ecosystems: novel fire effects and consequences for long-unburned ecosystems

Author:

Varner, J. M.

Gordon, D. R.

Putz, F. E.

Hiers, J. K.

Year published:

2005

Publication Type:

Peer-reviewed literature

Abstract:

Biologically rich savannas and woodlands dominated by Pinus palustris once dominated the southeastern U.S. landscape. With European settlement, fire suppression, and landscape fragmentation, this ecosystem has been reduced in area by 97%. Half of remnant forests are not burned with sufficient frequency, leading to declines in plant and animal species richness. For these fire-suppressed ecosystems a major regional conservation goal has been ecological restoration, primarily through the reinitiation of historic fire regimes. Unfortunately, fire reintroduction in long-unburned Longleaf pine stands can have novel, undesirable effects. We review case studies of Longleaf pine ecosystem restoration, highlighting novel fire behavior, patterns of tree mortality, and unintended outcomes resulting from reintroduction of fire. Many of these pineland restoration efforts have resulted in excessive overstory pine mortality (often >50%) and produced substantial quantities of noxious smoke. The most compelling mechanisms of high tree mortality after reintroduction of fire are related to smoldering combustion of surface layers of organic matter (duff) around the bases of old pines. Development of effective methods to reduce fuels and competing vegetation while encouraging native vegetation is a restoration challenge common to fire-prone ecosystems worldwide that will require understanding of the responses of altered ecosystems to the resumption of historically natural disturbances.

Title:

Mixed-effects height-diameter models for pine plantations in northern Florida and Georgia

Author:

VanderSchaaf, C. L.

Huang, S.

McConnell, T. E.

Trincado, G.

Yang, Y.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Mixed-effects individual tree height-diameter models are presented for commercially and ecologically important pines in northern Florida and Georgia. USA. Equations are presented for trees within plantations of loblolly (.Pinus laeda L.), longleaf (Pinus palustris P. Mill.), sand (Pints clausa (Chapm. ex Engelm.) Vasey ex Sarg.), and slash (Pinus elliollii Engelm.) pine. After obtaining height-diameter measurements from a plot/stand of interest, these mixed-effects models can be calibrated to produce localized individual tree height estimates. Based on model calibration of independent data from South Carolina, the use of two or three trees from a plot to calibrate the model provides a reasonable compromise between predictive ability and field sampling times. If calibrated at the stand-level, three trees could be used but larger sample sizes of 10 or 15 would likely produce more accurate estimates. To calibrate these models for specific plots/stands, an Excel spreadsheet isavailable on request.

Title:

Predictive ability of mixed-effects height-diameter models fit using one species but calibrated for another species

Author:

VanderSchaaf, C. L.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Mixed-effects individual tree height–diameter models are presented for important pines in the Western Gulf, USA. Equations are presented for plantations of loblolly (Pinus taeda L.), longleaf (Pinus palustris P. Mill.), shortleaf (Pinus echinata Mill.), and slash (Pinus elliottii Engelm.) pine. To produce localized individual tree height estimates, these models can be calibrated after obtaining height–diameter measurements from a plot/stand of interest. These equations can help answer an interesting question of whether a model fit for one species can be calibrated to produce reasonable height estimates of another species. In situations where mixed-effects models have not been developed for a particular species, perhaps an equation from another species can be used. This question was addressed by calibrating these models using independent data of loblolly, longleaf, and slash pine plantations located in South Carolina. For each calibration species, in addition to the models developed described above, previously published models, but of the same model form, fit using other species from across the USA were examined. Results show that models of a variety of species can be calibrated to provide reasonable predictions for a particular species. Predictions using this particular model form indicate that model calibration is more important than species-specific height–diameter relations.

Title:

A comparison of bee communities between primary and mature secondary forests in the longleaf pine ecosystem

Author:

Ulyshen, M. D.

Pokswinski, S. M.

Hiers, J. K.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Much of the once-dominant longleaf pine (Pinus palustris Mill.) ecosystem has been lost from the Coastal Plain of the southeastern United States and only a few scattered remnants of primary forest remain. Despite much interest in understanding and restoring this ecosystem, relatively few studies have attempted to characterize or assess the conservation status of the longleaf bee fauna. The objective of this study was to compare the diversity and composition of bee communities between primary and mature secondary (>100 years old) fire-maintained forests in Georgia and Florida. We used colored pan traps to sample bees at three primary and four secondary locations divided between two regions characterized by sandy (Eglin Air Force Base) or clayey (Red Hills) soils. There were no overall differences between primary and secondary forests in bee richness, diversity, evenness or abundance. Community composition differed among locations but we found no evidence that primary remnants provide critical habitat to sensitive bee species.

Title:

A comparison of coarse woody debris volume and variety between old-growth and secondary longleaf pine forests in the southeastern United States

Author:

Ulyshen, M. D.

Horn, S.

Pokswinski, S. M.

McHugh, J. V.

Hiers, J. K.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Few efforts have been made to quantify the amount and variety of deadwood in frequently burned ecosystems, particularly the longleaf pine (Pinus palustris Mill.) ecosystem of the southeastern United States. Moreover, comparisons of coarse woody debris between old-growth and secondary longleaf pine forests are lacking despite the widely recognized value of deadwood to biodiversity in many forest types. We measured standing and fallen deadwood in three old-growth and four mature (100–125 years-old) secondary forests in two landscapes characterized by either sandy or clayey soils within the historic range of P. palustris. Downed coarse woody debris volume was variable at the old-growth locations, ranging from 2.51 ± 0.79 to 29.10 ± 14.55m3 per ha, which includes perhaps the lowest values ever reported from any old-growth forest. Factors likely contributing to these low volumes include frequent fire, the low basal area characteristic of this forest type, subtropical climatic conditions of the southeastern Coastal Plain, and large termite populations. The high variability observed among the three old-growth locations probably reflect interactions between fire and other disturbances (e.g., wind damage). The old-growth location on sandy soils had significantly higher coarse woody debris volume and deadwood variety (e.g., diameter increments, posture, tree genera and decay classes) than secondary forests sampled nearby. Highly resinous heartwood is a significant indicator of old-growth conditions relative to secondary locations, appearing to accumulate as a persistent fraction of the deadwood pool over time.

Title:

Agricultural land-use history and restoration impact soil microbial biodiversity

Author:

Turley, N. E.

Bell-Dereske, L.

Evans, S. E.

Brudvig, L. A.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

1. Human land uses, such as agriculture, can leave long-lasting legacies as ecosystems recover. As a consequence, active restoration may be necessary to overcome landuse legacies; however, few studies have evaluated the joint effects of agricultural history and restoration on ecological communities. Those that have studied this joint effect have largely focused on plants and ignored other communities, such as soil microbes. 2. We conducted a large-scale experiment to understand how agricultural history and restoration tree thinning affect soil bacterial and fungal communities within longleaf pine savannas of the southern United States. This experiment contained 64 pairs of remnant (no history of tillage agriculture) and post-agricultural (reforested following abandonment from tillage agriculture >60 years prior) longleaf pine savanna plots. Plots were each 1 ha and arranged into 27 blocks to minimize land-use decision-making biases. We experimentally restored half of the remnant and post-agricultural plots by thinning trees to reinstate open-canopy savanna conditions and collected soils from all plots five growing seasons after tree thinning. We then evaluated soil bacterial and fungal communities using metabarcoding. 3. Agricultural history increased bacterial diversity but decreased fungal diversity, while restoration increased both bacterial and fungal diversity. Both bacterial and fungal richness were correlated with a range of environmental variables including above-ground variables like leaf litter and plant diversity, and below-ground variables such as soil nutrients, pH and organic matter, many of which were also impacted by agricultural history and restoration. 4. Fungal and bacterial community compositions were shaped by restoration and agricultural history resulting in four distinct communities across the four treatment combinations. 5. Synthesis and applications. Past agricultural land use has left persistent legacies on soil microbial biodiversity, even over half a century after agricultural abandonment and after intensive restoration activities. The impacts of these changes on soil microbe biodiversity could influence native plant establishment, plant productivity and other aspects of ecosystem functioning following agricultural abandonment and during restoration.

Title:

Dispersal and establishment limitation slows plant community recorvery in post-agricultural longleaf pine savannas.

Author:

Turley, N. E.

Orrock, J. L.

Ledvina, J. A.

Brudvig, L. A.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

1. Abandoned agricultural lands often have distinct plant communities from areas with no history of agriculture because plant species fail to recolonize. This may be due to dispersal limitation from a lack of seeds, or establishment limitation because of unsuitable environmental conditions. However, few experiments have directly tested how restoration activities may overcome these limitations. 2. We studied longleaf pine savannas in South Carolina abandoned from agriculture >60 years ago that were immediately adjacent to remnant habitats (areas with no history of agriculture). Using 27 sites, we conducted a factorial experiment that sowed seeds of 12 species indicative of remnant communities and conducted restoration thinning of overstorey trees in half of 126, 1-ha patches to mimic canopy density of natural savannas. We also established vegetation transects to examine if restoration promotes spread of remnant species into post-agricultural areas. 3. We found strong evidence for dispersal limitation in post-agricultural areas as over 99% of the occurrences of our focal species were in seed addition plots. Seed additions increased total species richness by 27%. 4. Restoration thinning increased establishment in seed addition plots (measured as richness of sown species) by 126% and increased total richness by 88%. Restoration thinning also increased seed production in remnant habitats by an average of 6506% across our focal species. However, after 4 years, restoration thinning did not facilitate the natural spread of remnant species into adjacent post-agricultural sites. 5. Synthesis and applications. We show that both dispersal and establishment limitation are key factors causing some plant species to be absent from post-agricultural sites. Dense canopy conditions limit seed production in remnant habitats and reduce establishment in post agricultural areas. Restoration thinning helps overcome these limitations and should facilitate the natural spread of species from remnant habitats but natural recovery may still be slow. Our results suggest that accelerating the recovery of post-agricultural habitats will require active restoration that reduces dispersal limitation (seed additions) and reinstates appropriate ecological conditions.

Title:

Breeding productivity of Bachman’s sparrows in fire-managed longleaf pine forests

Author:

Tucker, J. W.

Robinson, W. D.

Grand, J. B.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

Bachman's sparrow (Aimophila aestivalis), a near endemic songbird of the longleaf pine (Pinus palustris) ecosystem, is known to respond positively to prescribed fires. The influence of season (growing vs. dormant) and frequency (1 to ≥4 yr since burning) of fire on density of Bachman's sparrows, however, is poorly understood. We examined effects of fire on density of Bachman's sparrows in longleaf pine forests at the Conecuh National Forest, Alabama, and Blackwater River State Forest, Florida, USA. Density of Bachman's sparrows was greater the first 3 years after burning than ≥4 years after burning, and season of burning had little effect on the density of Bachman's sparrows. Percent coverage by grass had a greater influence on density of Bachman's sparrows than either season or frequency of burning. Percent canopy cover had a strong negative effect on coverage of grass but had a weaker effect on grass at stands burned frequently during the growing season. Growing-season fires (Apr–Sep) did not adversely affect density of Bachman's sparrows. Results from our study suggest that management and restoration of longleaf pine communities probably can be accomplished best by burning on a 2–3-year rotation during the growing season, when most fires historically occurred. Suppression of fire, or burning at intervals >4–5 years, will greatly reduce or eliminate habitat required by Bachman's sparrows.

Title:

Influence of fire on Bachman’s sparrow, an endemic North American songbird

Author:

Tucker, J. W.

Robinson, W. D.

Grand, J. B.

Year published:

2004

Publication Type:

Peer-reviewed literature

Abstract:

Bachman's sparrow (Aimophila aestivalis), a near endemic songbird of the longleaf pine (Pinus palustris) ecosystem, is known to respond positively to prescribed fires. The influence of season (growing vs. dormant) and frequency (1 to ≥4 yr since burning) of fire on density of Bachman's sparrows, however, is poorly understood. We examined effects of fire on density of Bachman's sparrows in longleaf pine forests at the Conecuh National Forest, Alabama, and Blackwater River State Forest, Florida, USA. Density of Bachman's sparrows was greater the first 3 years after burning than ≥4 years after burning, and season of burning had little effect on the density of Bachman's sparrows. Percent coverage by grass had a greater influence on density of Bachman's sparrows than either season or frequency of burning. Percent canopy cover had a strong negative effect on coverage of grass but had a weaker effect on grass at stands burned frequently during the growing season. Growing-season fires (Apr–Sep) did not adversely affect density of Bachman's sparrows. Results from our study suggest that management and restoration of longleaf pine communities probably can be accomplished best by burning on a 2–3-year rotation during the growing season, when most fires historically occurred. Suppression of fire, or burning at intervals >4–5 years, will greatly reduce or eliminate habitat required by Bachman's sparrows.

Title:

Mapping and modeling ecological conditions of longleaf pine habitats in the Apalachicola National Forest

Author:

Trager, M. D.

Drake, J. B.

Jenkins, A. M.

Petrick, C. J.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

We developed a historical natural community map and a spatially explicit ecological condition model (ECM) to evaluate conditions of the Apalachicola National Forest’s longleaf pine habitats. We identified and mapped historical vegetation patterns across the forest and then compared current vegetation structure derived from LiDAR and field surveys to desired conditions for the respective habitat types. In the first example of how these tools may be applied, we show how the natural communities map improved our understanding of wet savanna distribution and how the ECM then revealed opportunities and challenges for managing this unique habitat. In the second example, we show that the ECM scores were closely aligned with red-cockaded woodpecker habitat selection at three nested spatial scales relevant for that species’ ecology. Both of these analyses demonstrate how historical data and ecological condition assessments improve our understanding of resource patterns and may inform possible management actions.

Title:

Nitrogen fixation does not balance fire-induced nitrogen losses in longleaf pine savannas.

Author:

Tierney, J. A.

Hedin, L. O.

Wurzburger, N.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Fire is a critical force in structuring ecosystems, but it also removes substantial amounts of nitrogen (N), which can limit plant growth. Biological N fixation (BNF) may alleviate fire-induced N deficiencies that inhibit ecosystem recovery, yet if and how BNF achieves this under frequent fire is unclear. This problem is further complicated in the context of modern human influences (such as land-use history and atmospheric N deposition), which may confound the relationship between fire and fixation. Here, we investigate whether BNF supplies the N necessary to replace fire-induced N losses in restored longleaf pine savannas, and, if so, what factors control fixation. We established 54 1-ha plots of longleaf pine capturing 227 yr of forest recovery and a broad gradient of fire return interval (1.5–20 yr) at two sites in the southeastern United States. We quantified N fixation from three functional groups (herbaceous legumes, soil crusts, and asymbiotic N fixing bacteria), N losses from individual fire events and ecosystem dynamics of N supply and demand. We found that BNF rates were low but sustained over stand age but were substantially below estimated rates of atmospheric N deposition. While fire temporarily stimulated BNF from herbaceous legumes, neither BNF nor atmospheric N deposition were sufficient to balance N losses from fire and soil N stocks declined over stand age. However, rates of N mineralization were surprisingly high and tree productivity was unrelated to N availability, questioning the importance of N limitation in these temperate savannas. While it is possible that progressive N losses signal a decline in ecosystem resiliency, N enrichment from multiple land-use transitions and anthropogenic N deposition may suppress rates of BNF or diminish its importance as a long-term N balancing source in these pyrogenic ecosystems. In this case, fire may be acting as relief mechanism, critical for returning the modern longleaf pine landscape to its historical oligotrophic condition.

Title:

Effects of prescribed burning on amphibian diversity in a southeastern U.S. national forest

Author:

Schurbon, J. M.

Fauth, J. E.

Year published:

2004

Publication Type:

Peer-reviewed literature

Abstract:

Fire alters the abundance and diversity of many species, but its effects on amphibians are poorly known. We tested whether prescribed burning affected amphibian abundance and diversity within the Francis Marion National Forest, South Carolina, by monitoring assemblages at 15 temporary ponds with five different burn histories: 0, 1, 3, 5, and 12 years after burns. We also monitored terrestrial and aquatic environmental variables likely to influence amphibian diversity, such as leaf-litter depth, pond water chemistry, and distance to neighboring ponds. Fire had significant negative effects. Immediate effects (burning during the study) explained 12.8% and 10.8% of the variation in anuran and amphibian abundance, respectively, whereas short-term effects explained 31.8% and 24.6% of variation in amphibian species richness and evenness, respectively. Species richness increased and evenness decreased with time since burn, primarily because salamanders were rarely encountered at sites burned within 2 years. These sites had the shallowest leaf litter and highest soil temperature variances. Environmental factors unrelated to burning also significantly influenced amphibian diversity. Water chemistry explained 31.1% of variation in species richness, 32.2% of evenness, and 25% of anuran, salamander, and total amphibian abundances. Salamanders were most sensitive to water chemistry factors, particularly pH. Our results suggest that decreasing the frequency of prescribed burns from the current 2–3 years to 3–7 years will better maintain diverse amphibian and plant assemblages. Substituting growing-season burns for the current practice of winter and spring burns would avoid repeatedly interrupting amphibian breeding and would maintain the desired longleaf pine community.

Title:

Ecology and management of bark beetles (Coleoptera: Curculionidae: Scolytinae) in southern pine forests

Author:

Schowalter, T. D.

Year published:

2012

Publication Type:

Peer-reviewed literature

Abstract:

Bark beetles (Coleoptera: Curculionidae: Scolytinae) have been an important historic and current factor affecting pine forest production in the southern United States. Although tree mortality to bark beetles often detracts from forest management goals, the natural role of bark beetles is canopy opening, thinning, and diversification of stand structure and composition, effects that contribute to some ecosystem services in forests managed for multiple uses. Strategies to prevent bark beetle outbreaks exploit their sensitivity to host tree spacing and reliance on pheromones to attract sufficient numbers to overwhelm tree defenses. Tree species selection at planting or through selective thinning can favor pine species that are more tolerant of site conditions and resistant to bark beetles. Precommercial or commercial thinning improves tree condition and creates barriers to beetle population growth and spread. Remedial options include salvage harvest, pheromones for trap-out or disruption of host location, and white paint to disrupt the dark silhouette of the tree bole. Given the labor costs and trade-offs among tactics and the marginal profitability of fiber and timber production, harvest in advance of, or salvage harvest after, bark beetle attack often is the favored management strategy. However, this strategy is not as appropriate in public forests managed for values provided by older, more vulnerable trees. High-value sites for cultural or endangered species protection may require use of more expensive management options.

Title:

Physiological mechanisms of foliage recovery after spring or fall crown scorch in young longleaf pine (Pinus palustris Mill.).

Author:

Sayer, M. A. S.

Tyree, M. C.

Kuehler, E. A.

Jackson, J. K.

Dillaway, D. N.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

We hypothesized that physiological and morphological responses to prescribed fire support the post-scorch foliage recovery and growth of young longleaf pine. Two studies conducted in central Louisiana identified three means of foliage regrowth after fire that included an increase in the gas exchange rate of surviving foliage for 3 to 4 months after fire. Saplings also exhibited crown developmental responses to repeated fire that reduced the risk of future crown scorch. Starch reserves were a source of carbon for post-scorch foliage regrowth when fire was applied in the early growing season. However, the annual dynamics of starch accumulation and mobilization restricted its effectiveness for foliage regrowth when fire was applied late in the growing season. As such, post-scorch foliage regrowth became increasingly dependent on photosynthesis as the growing season progressed. Additionally, the loss of foliage by fire late in the growing season interrupted annual starch dynamics and created a starch void between the time of late growing season fire and mid-summer of the next year. The occurrence of drought during both studies revealed barriers to foliage reestablishment and normal stem growth among large saplings. In study 1, spring water deficit at the time of May fire was associated with high crown scorch and poor foliage and stem growth among large saplings. We attribute this lag in stem growth to three factors: little surviving foliage mass, low fascicle gas exchange rates, and poor post-scorch foliage recovery. In study 2, May fire during a short window of favorable burning conditions in the tenth month of a 20-month drought also reduced stem growth among large saplings but this growth loss was not due to poor post-scorch foliage recovery. Application of this information to prescribed fire guidelines will benefit young longleaf pine responses to fire and advance efforts to restore longleaf pine ecosystems.

Title:

Foliage re-establishment of Pinus palustris Mill. Saplings after spring or fall prescribed fire

Author:

Sayer, M. A. S.

Tyree, M. C.

Dillaway, D. N.

Rudd, B. M.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Repeated fire is key to the viability of longleaf pine (Pinus palustris Mill.) ecosystems, but its acceptance as a management tool may depend on satisfactory longleaf pine growth. This is because longleaf pine establishment often has the dual-purpose of ecosystem restoration and stemwood production. Timely recovery of scorched foliage among longleaf pine seedlings and saplings supports maximum juvenile growth. We identified two means of foliage re-establishment in the growing season after prescribed fire regardless of the season of fire application. New foliage growth after spring or fall fire was correlated with un-scorched foliage biomass and the presence of lateral branches. After prescribed fire in spring, foliage biomass recovery also appeared to benefit from the mobilization of starch. The high carbon demand of foliage recovery after fall prescribed fire was associated with interruption of seasonal starch accumulation in the stem and taproot. The implication of low starch accumulation in stem and taproot tissues during the growing season after fall prescribed fire is unknown and warrants further investigation. Our results demonstrate a positive influence of residual foliage, lateral branches, and stored starch on timely foliage recovery of young longleaf pines after fire. Together with knowledge of longleaf pine development and fuel and climate conditions at the time of prescribed fire, this information will aid prescribed fire practitioners charged with maintaining longleaf pine stands of high vigor.

Title:

Eastern wild turkey roost-site selection in a fire-maintained longleaf pine ecosystem

Author:

Sasmal, I.

Kilburg, E. L.

DePerno, C. S.

Chitwood, M. C.

Lashley, M. A.

Collier, B. A.

Moorman, C. E.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Night-time roosting in Meleagris gallopavo (Wild Turkey) is a quotidian activity that minimizes vulnerability to predators and weather. Roost-site selection in managed Pinus palustris (Longleaf Pine) communities is poorly documented. We assessed roost-site selection by comparing use and availability of vegetation types at the individual female Wild Turkey home-range level. We monitored 14 Wild Turkeys from February 2011 to June 2012. The Wild Turkeys did not use vegetation types within the estimated home ranges for roosting in proportion to availability (χ² = 601.696, P < 0.001). Female Wild Turkeys roosted in the upland Longleaf Pine in proportion to availability, selected for lowland hardwood, and avoided upland hardwood patches. We documented that roost-site availability is not likely a limiting factor in managed Longleaf Pine forests.

Title:

Influence of vegetation type and prescribed fire on Peromyscus abundance in a longeleaf pine ecosystem

Author:

Sasmal, I.

DePerno, C. S.

Swingen, M. B.

Moorman, C. E.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Prescribed fire temporarily can alter food and cover resources for ground-dwelling wildlife, potentially leading to changes in animal abundance. Small mammals are an important ecosystem component in many terrestrial communities and depend on ground-level vegetation most commonly affected by prescribed fire. In this complex system of food and cover availability where easier access to food might compromise cover, and vice versa, it is imperative to study post fire habitat use by mice and other ground-dwelling wildlife. We evaluated effects of time since burn and vegetation type on Peromyscus spp. abundance in alongleafpine(Pinus palustris) ecosystem in Fort Bragg Military Installation, North Carolina, USA, during 2011 and 2012. We trapped in 5 vegetation types and captured 208 individual Peromyscus. Peromyscus abundance did not differ among 1, 2, and 3 years post burn upland pine vegetation types, although we noted a trend of decreasing abundance as time since burn increased; however, abundance was greater in the lowland hardwood vegetation type than in open areas (i.e.,military dropzones). The lack of an effect of time since burn could be due to the short fire-return interval at the study site, which limited the time for post burn shifts in the composition of the understory from herbaceous to woody plant species. Therefore, we suggest future research in the longleaf pine ecosystem incorporate a wider time frame to assess short-and long-term effects of fire on small mammal populations.

Title:

Drought of a Pinus palustris plantation

Author:

Samuelson, L. J.

Stokes, T. A.

Ramirez, M. R.

Mendonca, C. C.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine (Pinus palustris Mill.) forests are thought to be drought tolerant and if so, planting longleaf pine presents a forest management strategy for climate change adaptation in the southeastern United States (U.S.). To better understand how longleaf pine copes with drought, leaf water relations, sap flow, canopy stomatal conductance (GS), and growth were studied over three growing seasons in response to ambient throughfall (ambient treatment) versus an approximate 40% reduction in throughfall (drought treatment) in a 13-year-old plantation. An exceptional drought occurred the first year of the study and decreased mean predawn (ΨPD) and midday (ΨMD) leaf water potential to −2.9 MPa and −3.6 MPa, respectively, and decreased average monthly midday Gs to near zero for at least one month in both treatments. Stomatal closure occurred at a ΨMD of −3.0 MPa in both treatments. Leaf water potentials and transpiration recovered quickly following significant rain events that terminated the drought and mortality was similar among years and treatments (2.8%). Longleaf pine responded to drought treatment with greater stomatal control of plant water loss rather than adjustments in leaf area, the sapwood to leaf area ratio, or leaf water potential at the turgor loss point (ΨTLP). Annual transpiration per unit leaf area was reduced 16% by drought treatment, but greater stomatal control of water loss in response to drought treatment was associated with decreases in growth efficiency and volume, and no improvement in water use efficiency.

Title:

Ecosystem carbon density and allocation across a chronosequence of longleaf pine forests

Author:

Samuelson, L. J.

Stokes, T. A.

Butnor, J. R.

Johnsen, K. H.

Gonzalez-Benecke, C. A.

Martin, T. A.

Cropper Jr., W. P.

Anderson, P. H.

Ramirez, M. R.

Lewis, J. C.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Forests can partially offset greenhouse gas emissions and contribute to climate change mitigation, mainly through increases in live biomass. We quantified carbon (C) density in 20 managed longleaf pine (Pinus palustris Mill.) forests ranging in age from 5 to 118 years located across the southeastern United States and estimated above-and belowground C trajectories. Ecosystem C stock (all pools including soil C) and aboveground live tree C increased nonlinearly with stand age and the modeled asymptotic maxima were 168 Mg C/ha and 80 Mg C/ha, respectively. Accumulation of ecosystem C with stand age was driven mainly by increases in aboveground live tree C, which ranged from <1 Mg C/ha to 74 Mg C/ha and comprised <1% to 39% of ecosystem C. Live root C (sum of below-stump C, ground penetrating radar measurement of lateral root C, and live fine root C) increased with stand age and represented 4–22% of ecosystem C. Soil C was related to site index, but not to stand age, and made up 39–92% of ecosystem C. Live understory C, forest floor C, downed dead wood C, and standing dead wood C were small fractions of ecosystem C in these frequently burned stands. Stand age and site index accounted for 76% of the variation in ecosystem C among stands. The mean root-to- shoot ratio calculated as the average across all stands (excluding the grass-stage stand) was 0.54 (standard deviation of 0.19) and higher than reports for other conifers. Long-term accumulation of live tree C, combined with the larger role of belowground accumulation of lateral root C than in other forest types, indicates a role of longleaf pine forests in providing disturbance-resistant C storage that can balance the more rapid C accumulation and C removal associated with more intensively managed forests. Although other managed southern pine systems sequester more C over the short-term, we suggest that longleaf pine forests can play a meaningful role in regional forest C management.

Title:

Biomass and taper for trees in thinned and unthinned longleaf pine plantations

Author:

Thomas, C. E.

Parresol, B.

Le, K.

Lohrey, R. E.

Year published:

1995

Publication Type:

Peer-reviewed literature

Abstract:

Longleafpine (Pinus palustrisMil1.) trees growing in thinnedplantation studies in Louisiana and Texas and unthinned stands from the Louisiana sites were sampledfor establishing taper, volume, and specific gravity. Stem analysis data were collected on 147stems ranging in agefrom 30 to 50 yr. Analyses of covariance (ANCOVAs) were employed to determine coefJicients and to detect differences among treatments, for tree taper and specific gravity. Taper and volume equation coefficients and statistics at specified ages were developedfor intermediate plantation ages by examining and aging internal growth ringsfrom the stem sections. Biomass was computed by combining the taper and specific gravity equations. Seemingly unrelated regression (SUR) was used to simultaneouslyfit the system offour equations composed of specific gravity, taper, volume, and biomass, because of the correlated error structure of these equations. Biomass equations, however, could not be developedfor the intermediate ages because specific gravity could not be determined or related to earlier tree ages.

Title:

Deer and cattle diet overlap on Louisiana pine-bluestem range

Author:

Thill, R. E.

Martin, A.

Year published:

1986

Publication Type:

Peer-reviewed literature

Abstract:

Seasonal diets of 5 cattle and 3-5 tame white-tailed deer (Odocoileus virginianus) on 3 subunits of a rotationally burned, continuously grazed longleaf pine (Pinus palustris)-bluestem (Andropogon spp.) range in Louisiana are compared with diets of these same deer on 3 similarly managed ungrazed subunits. Forage-class use by deer was more affected by burning than grazing, except during winter. Winter diets were affected by grazing, with deer selecting more herbage and less browse on grazed than on ungrazed sites. February burning reduced diet overlap substantially during spring. Within the 1st year after burning, diet overlap averaged 21.5, 11.2, 19.6, and 30.9% during spring, summer, fall, and winter, respectively.

Title:

Linking knowledge to action: the role of boundary spanners in translating ecology

Author:

Safford, H. D.

Sawyer, S. C.

Kocher, S. D.

Hiers, J. K.

Cross, M.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

One of the most effective ways to foster the co-production of ecological knowledge by producers and users, as well as encouraging dialogue between them, is to cultivate individuals or organizations working at and managing the boundary between the two groups. Such “boundary spanners” are critical to ensuring scientific salience, credibility, and legitimacy, yet they remain relatively underused in ecology. We summarize some of the major roles of boundary spanners in translational ecology, and suggest that effectiveness in translating ecological information depends on several key factors. These include organizational and individual commitment to boundary spanning over the long term; development of useful, co-produced products and tools that can subsequently assume boundary-spanning roles of their own; dual-accountability frameworks that involve both science providers and users; and identification, training, and retention of science translators who possess a suite of professional skills and individual traits that are rare in scientific circles.

Title:

Small-scale fuel variation alters fire intensity and shrub abundance in a pine savanna

Author:

Thaxton, J. M.

Platt, W. J.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

Small-scale variation in fire intensity and effects may be an important source of environmental heterogeneity in frequently burned plant communities. We hypothesized that variation in fire intensity resulting from local differences in fuel loads produces heterogeneity in pine savanna ground cover by altering shrub abundance. To test this hypothesis, we experimentally manipulated prefire fuel loads to mimic naturally occurring fuel-load heterogeneity associated with branch falls, needle fall near large pines, and animal disturbances in a frequently burned longleaf pine (Pinus palustris) savanna in Louisiana, USA. We applied one of four fuel treatments (unaltered control, fine-fuel removal, fine-fuel addition, wood addition) to each of 540 (1-m2) quadrats prior to growing-season prescribed fires in each of two years (1999 and 2001). In both years fuel addition increased (and fuel removal decreased) fuel consumption and maximum fire temperatures relative to unaltered controls. Fuel addition, particularly wood, increased damage to shrubs, increased shrub mortality, and decreased resprout density relative to controls. We propose that local variation in fire intensity may contribute to maintenance of high species diversity in pine savannas by reducing shrub abundance and creating openings in an otherwise continuous ground cover.

Title:

A macroscopic charcoal and multiproxy record from peat recovered from depression marshes in longleaf pine sandhills, Florida, USA

Author:

Tanner, B.

Douglas, M.

Greenberg, C. H.

Chamberlin, J.

Styers, D.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Science-based information on historical fire frequency is lacking for longleaf pine sandhills. We undertook a high-resolution macroscopic charcoal and geochemical analysis of sediment cores recovered from three depression marshes located within a longleaf pine sandhill ecosystem in Florida, USA. A ~1500-year fire history reconstructed from >1.5 m length peat cores analyzed at decadal to multi-decadal resolution revealed abundant macroscopic charcoal particles at nearly all sampling intervals, suggesting that fire occurred near the sites for almost all decades represented in the deposit. This result supported previous hypotheses of a frequent natural fire return interval for Florida’s longleaf pine sandhills and suggested that management decisions for this ecosystem should continue to focus on the frequent prescription of controlled burns. Our research also demonstrated that some of Florida’s depression marshes contain a >3000-year archive of organic-rich peat. Bulk elemental carbon and nitrogen data and stable carbon isotope analysis of the deposits at two of the three study sites suggested persistently wet soils. Soil data from the third site suggested that drying and peat oxidation occurred periodically. These depression marshes rapidly sink carbon, with measured sequestration rates on the order of 16 to 56 g m?2 yr?1. Our research demonstrated that Florida’s depression marshes provide an untapped record of paleoenvironmental information.

Title:

Economic viability of longleaf pine management in the Southeastern United States

Author:

Susaeta, A.

Gong, P.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

The lack of economic information for management of longleaf pine, a forest type that once dominated the landscape in the southeastern United States, can be a major barrier to landowners to planting this species. This study compares the economic performance of even-aged longleaf pine with loblolly pine. We assume that a longleaf pine stand produces timber, water yield, wildlife habitats and pinestraw raking, while a loblolly pine stand is managed exclusively for timber production. For both species, future timber prices are uncertain and harvest decisions will be made following an optimal adaptive harvest strategy. Our findings show that investing in longleaf pine plantations is not generally an economically attractive option compared to loblolly pine for landowners. On average, the land expectation value for loblolly pine is $4610 ha−1 higher than the land expectation value of longleaf pine. Stronger markets for water yield ($0.04–$0.073 k-liter−1) can favor the competitiveness of longleaf over loblolly pine. In the absence of increased payments for water production, landowners require financial incentives between $235–$642 ha−1 over 15 years, to switch from planting loblolly to longleaf pine. When water payments are included ($0.03–$0.0 k-liter−1), incentives between $173–320 ha−1 are required to plant longleaf instead of loblolly pine.

Title:

The impact of prescribed burning on native bee communities (Hymenoptera: Apoidea: Anthophila) in longleaf pine savannas in the North Carolina Sandhills

Author:

Moylett, H.

Youngstead, E.

Sorenson, C.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Prescribed burning is a common silvicultural practice used in the management of longleaf pine (Pinus palustris Mill.,Pinales: Pinaceae) savannas to reduce hardwood encroachment and ground cover and to maintain biodiversity. We investigated the response of the native bee community (Hymenoptera: Apoidea: Anthophila) in the Sandhills of North Carolina to prescribed burning on a 3-yr rotation over two consecutive years (2012 and 2013). We deployed bee bowl traps in sites that had been burned the year of sampling, 1 yr before, 2 yr before, and in unburned controls. In total, 2,276 bees of 109 species were captured. Bee abundance declined with time since fire, with 2.3 times more bees captured in the most recently burned sites than in unburned controls. Bee diversity also declined with time since fire, with 2.1 times more species captured in the most recently burned sites than in controls. Bee community composition also responded to fire; we present evidence that this response was mediated in part by the effect of fire on the amount of bare ground and canopy cover. Bees nesting aboveground were unaffected by fire, contrary to our expectation that fire would destroy the wood and stems in which these species nest. Our results indicate that prescribed burning is a silvicultural practice consistent with pollinator conservation in longleaf pine ecosystems of the North Carolina sandhills.

Title:

Silviculture that sustains: the nexus between silviculture, frequent prescribed fire, and conservation of biodiversity in longleaf pine forests of the southeastern United States

Author:

Mitchell, R. J.

Hiers, J. K.

O'Brien, J. J.

Jack, S. B.

Engstrom, R. T.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

The longleaf pine (Pinus palustris Mill.) forest ecosystem of the US southeastern Coastal Plain, among the most biologically diverse ecosystems in North America, originally covered over 24 x 106 ha but now occupy less than 5% of their original extent. The key factor for sustaining their high levels of diversity is the frequent application of prescribed fire uninterrupted in time and space. Pinus fuels, critical to application of fire and regulated by canopy distribution, provided the nexus between silviculture and fire management in this system. Typical silvicultural approaches for this type were, in large part, developed to maximize the establishment and growth of regeneration as well as growth and yield of timber, with much less regard to how those practices might influence the ability to sustain prescribed burning regimes or the associated biodiversity. However, many landholdings in the region now include conservation of biodiversity as a primary objective with sustained timer yield as an important but secondary goal. This review synthesizes the literature related to controls of biodiversity for longleaf pine ecosystems, and silvicultural approaches are compared in their ability to sustain natural disturbance such as fire and how closely they mimic the variation, patterns, and processes of natural disturbance regimes while allowing for regeneration.

Title:

Patterns of longleaf pine (Pinus palustris) establishment in wiregrass (Aristida beyrichiana) understories.

Author:

Miller, H. M.

Fill, F. M.

Crandall, R. M.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Ecosystem community structure and function is shaped in part by intra- and inter-specific interactions among plants. Facilitative interactions, wherein one plant benefits another’s fitness, can strongly influence plant community dynamics. We investigated the potential of an endemic, perennial bunchgrass, wiregrass (Aristida beyrichiana), to function as a nurse plant for longleaf pine (Pinus palustris) seedlings in fire-maintained pine savannas of the southeastern U.S.A. We documented significantly more pine seedlings growing close to established wiregrass bunchgrasses in a site burned one year prior to sampling. Pine seedlings growing close to wiregrass were also significantly taller than those growing further away. This positive spatial association between wiregrass and pine seedlings suggests that wiregrass facilitates early longleaf pine establishment in flatwoods environments, at least within the first year after fire.

Title:

Re-introducing fire at the urban-wild-land interface: planning for success

Author:

Miller, S. R.

Wade, D.

Year published:

2003

Publication Type:

Peer-reviewed literature

Abstract:

The application of fire in the southern United States continues to increase in complexity due to urban sprawl, air quality issues and regulatory constraints. Many sites suffer from unnaturally high fuel accumulations due to decades of fire exclusion. The loss of habitat to urbanization and successional changes resulting from the absence of fire increases the importance of restoring and maintaining those remaining acres. The wild-land/urban interface case study we discuss herein includes several fire-adapted plant communities ranging in required fire regime from frequent low-intensity fires to infrequent high-intensity stand replacement fires. This area has experienced extended fire-free periods and includes tightly packed homes in subdivisions developed with no consideration of the potential for wild-land fire. Additional smoke-sensitive areas include schools and heavily travelled highways. Such worst-case scenarios exponentially increase the challenges/risks facing fire managers. This case study thus illustrates many of the complex societal issues and technical challenges facing fire managers when planning and conducting restoration burns in the wild-land/urban interface. In fact, it reinforces the notion that, when burning in the wild-land/urban interface, executing the burn often requires less effort than the planning, co-operation and co-ordination necessary prior to ignition.

Title:

Quantitatively evaluating restoration experiments: research design, statistical analysis and data management considerations

Author:

Michener, W. K.

Year published:

1997

Publication Type:

Peer-reviewed literature

Abstract:

Conceptual and logistical challenges associated with the design and analysis of ecological restoration experiments are often viewed as being insurmountable, thereby limiting the potential value of restoration experiments as tests of ecological theory. Such research constraints are, however, not unique within the environmental sciences. Numerous natural and anthropogenic disturbances represent unplanned, uncontrollable events that cannot be replicated or studied using traditional experimental approaches and statistical analyses. A broad mix of appropriate research approaches (e.g., long-term studies, large-scale comparative studies, space-for-time substitution, modeling, and focused experimentation) and analytical tools (e.g., observational, spatial, and temporal statistics) are available and required to advance restoration ecology as a scientific discipline. In this article, research design and analytical options are described and assessed in relation to their applicability to restoration ecology. Significant research benefits may be derived from explicitly defining conceptual models and presuppositions, developing multiple working hypotheses, and developing and archiving high-quality data and metadata. Flexibility in research approaches and statistical analyses, high-quality databases, and new sampling approaches that support research at broader spatial and temporal scales are critical for enhancing ecological understanding and supporting further development of restoration ecology as a scientific discipline.

Title:

Ecological effects of alternative fuel-reduction treatments: highlights of the national fire fire-surrogate study (FFS)

Author:

McIver, J. D.

Stephens, S. L.

Agee, J. K.

Barbour, J.

Boerner, R. E. J.

Edminster, C. B.

Erickson, K. L.

Farris, K. L.

Fettig, C. J.

Fiedler, C. E.

Haase, S.

Hart, S. C.

Keeley, J. E.

Knapp, E. E.

Lehmkuhl, J. F.

Moghaddas, J. J.

Otrosina, W.

Outcalt, K. W.

Schwilk, D. W.

Skinner, C. N.

Waldrop, T. A.

Weatherspoon, C. P.

Yaussy, D. A.

Youngblood, A.

Zack, S.

Year published:

2010

Publication Type:

Peer-reviewed literature

Abstract:

The 12-site National Fire and Fire Surrogate study (FFS) was a multivariate experiment that evaluated ecological consequences of alternative fuel-reduction treatments in seasonally dry forests of the US. Each site was a replicated experiment with a common design that compared an un-manipulated control, prescribed fire, mechanical and mechanical þ fire treatments. Variables within the vegetation, fuelbed, forest floor and soil, bark beetles, tree diseases and wildlife were measured in 10-ha stands, and ecological response was compared among treatments at the site level, and across sites, to better understand the influence of differential site conditions. For most sites, treated stands were predicted to be more resilient to wildfire if it occurred shortly after treatment, but for most ecological variables, short-term response to treatments was subtle and transient. Strong site-specificity was observed in the response of most ecosystem variables, suggesting that practitioners employ adaptive management at the local scale. Because ecosystem components were tightly linked, adaptive management would need to include monitoring of a carefully chosen set of key variables. Mechanical treatments did not serve as surrogates for fire for most variables, suggesting that fire be maintained whenever possible. Restoration to pre-settlement conditions will require repeated treatments over time, with eastern forests requiring more frequent applications.

Title:

Vegetation structure, species diversity, and ecosystem processes as measures of restoration success

Author:

Ruiz-Jaen, M. C.

Aide, T. M.

Year published:

2005

Publication Type:

Peer-reviewed literature

Abstract:

Most restoration projects have focused on recovery of vegetation to assess restoration success. Nevertheless if the goal of a restoration project is to create an ecosystem that is self-supporting and resilient to perturbation, we also need information on the recovery of other trophic levels and ecosystem processes. To provide an example on how to assess restoration success, we compared four measures of vegetation structure, four measures of species diversity, and six measures of ecosystem processes among pre-reforested, reforested, and reference sites. In addition, we described how Bray Curtis Ordination could be used to evaluate restoration success. Vegetation structure recovered rapidly due to the increase in vegetation height and the decrease in herbaceous cover. Other measures such as litter cover, number of litter layers, and DBH size class values are recovering at slower rates, but they also have increased vegetation heterogeneity in the reforested site. Species diversity recovered rapidly. The increase in vegetation structure changed the local conditions in the reforested site facilitating the colonization of woody seedlings, ants, reptiles, and amphibians. Ecosystem processes, particularly litter production and turnover, have enhanced the incorporation of nutrients and organic matter in the soil. By including vegetation structure, species diversity, and ecosystem processes measures we have better information to determine the success of a restoration project. Moreover, the Subjective Bray Curtis Ordination is a useful approach for evaluating different restoration techniques or identifying measures that are recovering slowly and would benefit from additional management.

Title:

Conterminous U.S. and Alaska forest type mapping using Forest Inventory and Analysis data

Author:

Ruefenacht, B.

Finco, M. V.

Nelson, M. D.

Czaplewski, R.

Helmer, E. H.

Blackard, J. A.

Holden, G. R.

Lister, A. J.

Salajanu,D.

Weyermann, D.

Winterberger, K.

Year published:

2008

Publication Type:

Peer-reviewed literature

Abstract:

Classification-trees were used to model forest type groups and forest types for the conterminous United States and Alaska. The predictor data were a geospatial data set with a spatial resolution of 250 m developed by the U.S. Department of Agriculture Forest Service (USFS). The response data were plot data from the USFS Forest Inventory and Analysis program. Overall accuracies for the conterminous U.S. for the forest type group and forest type were 69 percent (Kappa = 0.66) and 50 percent (Kappa = 0.57), respectively. The overall accuracies for Alaska for the forest type group and forest type were 78 percent (Kappa = 0.69) and 67 percent (Kappa = 0.61), respectively. This is the first forest type map produced for the U.S. The forest type group map is an update of a previous forest type group map created by Zhu and Evans (1994).

Title:

Red-cockaded woodpeckers and silvicultural practice: is uneven-aged silviculture preferable to even-aged

Author:

Rudolph, D. C.

Conner, R. N.

Year published:

1996

Publication Type:

Peer-reviewed literature

Title:

Stand conditions and tree characteristics affect quality of longleaf pine for red-cockaded woodpecker cavity trees

Author:

Ross, W. G.

Kullhavy, D. L.

Conner, R. N.

Year published:

1997

Publication Type:

Peer-reviewed literature

Abstract:

We measured resin flow of longleaf (Pinus palustris Mill.) pines in red-cockaded woodpecker (Picoides borealis Vieillot) clusters in the Angelina National Forest in Texas, and the Apalachicola National Forest in Florida. Sample trees were categorized as active cavity trees, inactive cavity trees and control trees. Sample trees were further categorized by stand position as either edge or interior trees. Longleaf cavity trees in Texas and Florida had similar resin flow characteristics. Active cavity trees on forest edges had the highest resin flow, whereas active cavity trees in forest interiors had the lowest. Trees experiencing both low and high levels of red-cockaded woodpecker activity and competition from other trees had low resin flow, whereas intermediate stress * typically resulted in high resin flow. Results from this study indicate that the best active red-cockaded woodpecker cavity trees, from a resin flow perspective, are on or near forest edges. This may explain the woodpecker’s observed tendency to excavate new cavities near edges even 1L when interior basal area has been reduced and midstory has been controlled. Our results suggest that pines managed as potential cavity trees should be experiencing minimal competition, and that a mosaic of patches in red-cockaded woodpecker habitat may be preferable to more uniform conditions.

Title:

Red-cockaded woodpecker habitat management and longleaf pine straw production: an economic analysis

Author:

Roise, J. P.

Chung, J.

Lancia, R.

Year published:

1991

Publication Type:

Peer-reviewed literature

Abstract:

This paper contains an economic analysis of shelterwood management of longleaf pine (Pinus palustris Mill) with markets for both timber and pine straw. It was found that extended rotations required for red-cockaded woodpecker (Picoides borealis) habitat, while not optimal, are better when pine straw is also a market product han when considering timber alone. Rotation ages were fixed at 60, 80, 100, and 120 years to provide redcockaded woodpecker habitat. A single thinning is included with variable timing and intensity. Intensive site treatments are also included to control litter, grasses, hardwood, and brown spot disease. An equation for pine straw yield as a function of basal area is presented. Pine straw may i Funding for this study was provided in part by the Department of Energy, Savannah River Plant Operations Office, the USDA Forest Service, Southeastern Forest Experiment Station, and the Forestry Department, North Carolina State University. 88 SJAr 15(1991) increase soil expectation value by more than 230% over that provided by timber alone.

Title:

Responses of a forest-dwelling terrestrial turtle, Terrapene carolina, to presribed fire in a longleaf pine ecosystem

Author:

Roe, J. H.

Wild, K. H.

Chavez, M. S.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Prescribed fire is commonly used as a tool to meet a range of forest management goals. Owing to their limited movement abilities, terrestrial turtles are likely to be at high risk of injury and mortality, and to experience other fitness consequences with population-level implications from fire. Using radiotelemetry, we studied the responses of Eastern Box Turtles, Terrapene carolina carolina, to prescribed fire management in a sandhills Longleaf Pine forest system over a five-year period and compared our results to a nearby population in an unburned coastal plain location. Individual variation in turtle survival was strongly dependent on how frequently and extensively the areas were burned, with annual survival rates of 94.5% in unburned areas decreasing to 45.9% in the most extensively burned areas. Turtles at the fire-maintained sandhills site had annual survival rates 4.9% less than at the unburned coastal plain site, and females had annual survival rates 6.8% less than males. Survival varied seasonally, with greatest mortality rates in winter and spring, especially among females. Growth rates and body condition did not differ between sites, nor did they vary according to fire extent and frequency at the fire maintained site. Although mortality was greater and spatially variable at the fire- maintained site, annual survival rates across the site (86–90% for females and males, respectively) were comparable to other stable populations of T. carolina. The lesser than expected mortality rate at the fire-maintained site was likely the result of turtles’ strong selection of mesic hardwood forests near bottomlands and streams – habitats that may serve as refugia from fire. In areas where T. carolina conservation is a priority, land managers should integrate maintenance of fire refuge habitats into burn planning to minimize unintended negative impacts to this imperiled species.

Title:

Patchy fires promote regeneration of longleaf pine (Pinus palustris Mill.) in pine savannas.

Author:

Robertson, K. M.

Platt, W. J.

Faires, C. E.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Research Highlights: Spatial patterns of fire spread and severity influence survival of juvenile pines in longleaf pine savannas. Small areas that do not burn during frequent fires facilitate formation of patches of even-aged longleaf pine juveniles. These regeneration patches are especially associated with inner portions of openings (gaps) and where canopy trees have died in recent decades. Patterns of prescribed fire can thus have an important influence on stand dynamics of the dominant tree in pine savannas. Background and Objectives: Savannas are characterized by bottlenecks to tree regeneration. In pine savannas, longleaf pine is noted for recruitment in discrete clusters located within gaps away from canopy trees. Various mechanisms promoting this pattern have been hypothesized: light limitations, soil moisture, soil nutrients, pine needle mulching, competition with canopy tree roots, and fire severity associated with pine needle litter. We tested the hypothesis that regeneration patches are associated with areas that remain unburned during some prescribed fires, as mediated by gaps in the canopy, especially inner portions of gaps, and areas re-opened by death of canopy trees. Materials and Methods: We mapped areas that were unburned during prescribed fires applied at 1–2 year intervals from 2005–2018 in an old-growth pine savanna in Georgia, USA. We compared the maps to locations of longleaf pine juveniles (<1.5 m height) measured in 2018 and canopy cover and canopy tree deaths using a long-term (40 year) tree census. Results: Logistic regression analysis showed juveniles to be associated with unburned areas, gaps, inner gaps, and areas where canopy trees died. Conclusions: Patterns of fire spread and severity limit survival of longleaf pine juveniles to patches away from canopy trees, especially where canopy trees have died in recent decades. These processes contribute to a buffering mechanism that maintains the savanna structure and prevents transition to closed canopy forest or open grassland communities.

Title:

Problems with Schurbon and Fauth’s test of effects of prescribed burning on amphibian diversity

Author:

Robertson, K. M.

Ostertag, T. E.

Year published:

2004

Publication Type:

Peer-reviewed literature

Title:

Landscape corridors can increase invasion by an exotic species and reduce diversity of native species

Author:

Resasco, J.

Haddad, N. M.

Orrock, J. L.

Shoemaker, D.

Brudvig, L. A.

Damschen, E. I.

Tewksbury, J. J.

Levey, D. J.

Year published:

2014

Publication Type:

Peer-reviewed literature

Title:

Wildlife habitat condition in open pine woodlands: field data to refine management tagets

Author:

McIntyre, R. K.

Conner, L. M.

Jack, S. B.

Schlimm, E. M.

Smith, L. L.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Open pine ecosystems of the southern United States are a conservation priority for many agencies, organizations, and private landowners. These woodlands, characterized by moderately-stocked overstories, low cover of midstory, and grass-dominated herbaceous groundcover, provide important habitat for a suite of rare and declining wildlife species. To provide guidance for land managers engaged in habitat restoration in open pine ecosystems, ranges of desired conditions for elements of vegetation structure have been developed using literature survey and expert opinion. We compared empirical data on habitat occupancy for 17 wildlife species from second-growth longleaf pine woodlands in southwestern Georgia with recommended ranges for basal area (BA) of all pine, BA of pine≥35.5 cm dbh, percent canopy cover, percent herbaceous cover, and percent shrub cover. Vegetation data were taken from 864 monitoring plots and Mahalanobis distance models were used to develop habitat suitability indices from the wildlife data. Recommendations for shrub cover and BA of pines≥35.5 cm fit well with model predictions for all wildlife species. However, mean BA of all pines at sites used by wildlife were at the low end of the recommended range. Herbaceous cover at sites used by wildlife was well below the recommended range, whereas canopy cover was well above recommendations, suggesting these ranges should be expanded. These modifications could provide managers of open pine ecosystems greater flexibility, allowing them to incorporate a broader suite of objectives in their management while still providing habitat for wildlife species of concern. Moreover, our models suggest that monitoring presence of open pine indicator bird species may be an efficient method to assess restoration or management progress of open canopy pine systems.

Title:

Gaps in a gappy forest: plant resources, longleaf pine regeneration, and understory response to tree removal in longleaf pine savannas

Author:

McGuire, J. P.

Mitchell, R. J.

Moser, E. B.

Pecot, S. D.

Gjerstad, D. H.

Hedman, C. W.

Year published:

2001

Publication Type:

Peer-reviewed literature

Abstract:

Resource availability and planted longleaf pine (Pinus palustris Mill.) seedling and understory vegetation response within and among three sizes of experimentally created canopy gaps (0.11, 0.41, 1.63 ha) in a mature longleaf pine savanna were investigated for 2 years. Longleaf pine seedlings and understory vegetation showed increased growth in gaps created by tree removal. Longleaf pine seedling growth within gaps was maximized approximately 18 m from the uncut savanna. Increased longleaf pine seedling survival under the uncut savanna canopy observed after the first year suggests that the overstory may facilitate establishment of longleaf pine seedlings rather than reduce survival through competition. Despite the relative openness of the uncut longleaf pine forest, light quantity was increased by tree removal. Light was also the resource most strongly correlated with seedling and understory vegetation growth. Although net N mineralization was correlated to seedling response, the amount of variation explained was low relative to light. Belowground (root) gaps were not strong, in part because of non-pine understory roots increasing in biomass following tree removal. These results suggest that regeneration of longleaf pine may be maximized within gap sizes as small as approximately 0.10 ha, due largely to increases in light availability.

Title:

A space-time survival point process for a longleaf pine forest in southern Georgia

Author:

Rathbun, S. L.

Cressie, N.

Year published:

1994

Publication Type:

Peer-reviewed literature

Abstract:

A marked spatial point pattern of trees and their diameters is the result of a dynamic biological process that takes place over time as well as space. Such patterns can be modeled as realizations of marked space-time survival point processes, where trees are born at some random location and time and then live, grow, and produce offspring in a random fashion. A model for a marked space-time survival point process is fit to data from a longleaf pine ( Pinus palustris ) forest in southern Georgia. The space-time survival point process is divided into three components: a birth process, a growth process, and a survival process. Each of the component processes is analyzed individually, from which conclusions regarding the dynamic ecological processes can be made. By using this reductionist approach, questions concerning each individual process can be addressed that might not have been answerable otherwise.

Title:

Effects of chronic human activities on invasion of longleaf pine forests by sand pine

Author:

McCay, D. H.

Year published:

2000

Publication Type:

Peer-reviewed literature

Abstract:

Chronic human activities may result in new and permanent successional trajectories in certain ecosystems. The invasion of longleaf pine ecosystems by sand pine in the Florida Panhandle is one such change in the landscape. This study examined the spatial pattern of sand pine expansion and explored the natural and anthropogenic disturbances that fostered this invasion. Aerial photographs (1949, 1994) and Geographic Information Systems analyses confirmed sand pine expansion at Eglin Air Force Base. In 1949, there were 8,982 ha of sand pine in the southern portion of the study area near riparian and coastal lowland forests. By 1994, sand pine had expanded further upland and inland, for a total of 17,147 ha in the study area. Sand pine age data showed that this expansion had started by 1920 but increased rapidly in the 1940s. Historical accounts and structural data from stands suggest that land-use activities associated with the extraction of turpentine promoted the invasion by sand pine. Fires were suppressed in longleaf pine forests to protect turpentine trees, resulting in increased vegetation cover and decreased regeneration of longleaf pine. In addition, stands were typically harvested after turpentining, and there was little or no advanced regeneration of longleaf pine. Sand pine age histograms showed that the onset of high establishment rates (1940s) coincided with changes in land ownership and widespread fire suppression. Sand pine is likely to persist in these ecosystems due to its abundant regeneration.

Title:

Host preference of ectomycorrhizal fungi in mixed pine-oak woodlands

Author:

Rasmussen, A. L.

Busby, R. R.

Hoeksema, J. D.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Many ectomycorrhizal fungi (EMF) are generalists, but most plant genera that form ectomycorrhizas have at least some fungal partners that are specific to that host genus. Because shared mycorrhizal fungi mediate plant community interactions, host preference has implications for plant succession and competition. We studied the EMF of oaks (Quercus spp.) and pines (Pinus spp.) in a forest in northern Florida, USA, focusing on symbionts shared with longleaf pine (Pinus palustris Mill.). Longleaf pine is an important species in the southeastern USA, both for timber plantations and for restoring savanna and woodland habitat. However, we found no research on the composition of naturally occurring EMF on longleaf pine roots. A lower proportion of EMF operational taxonomic units (OTUs) were found colonizing both oaks and pines than expected, providing evidence of host preference within the community. Although most EMF were detected only on either oaks or pines, the OTUs found on both tended to be frequently occurring and abundant. Cenococcum OTUs were found to be significantly associated with oaks, an unexpected finding as this genus is widespread, with a broad host range. These results suggest that host preference of EMF may structure EMF communities and therefore influence ecosystem effects of mycorrhizal networks.

Title:

Low-dose herbicide effects on tree establishment and soil nitrogen biogeochemistry within pine savannas

Author:

McCaskill, G. L.

Jose, S.

Ogram, A. V.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine (Pinus palustris P. Mill) survival and growth, net nitrogen mineralization, and soil microbial biomass, were evaluated after four growing seasons in a Florida wet flatwoods site following chemical vegetation control during the first year or second year after planting, or during both years. The four herbicide treatments included sulfometuron methyl at 0.26 ai kg ha-1, hexazinone (0.56 ai kg ha-1), sulfometuron (0.26 ai kg ha-1) plus hexazinone (0.56 ai kg ha-1) mix, and imazapyr at 0.21 ai kg ha-1. Imazapyr was the only treatment to significantly improve growth over the control in a single application. Consecutive annual applications of imazapyr and hexazinone on seedlings also improved growth rates compared to the control. Sulfometuron methyl-treated pine trees had lower survival rates and were smaller than pines growing in the control plots after a single application. The survival and growth rates of imazapyr-treated seedlings were improved when the chemical was applied during the second growing season after planting, instead of the first year. Imazapyr and hexazinone applications increased net nitrogen mineralization rates, but imazapyr was the only treatment to increase ammonification; compared to the control. Microbial and fungal biomass carbon showed no differences between treatments. The results did show that microbial biomass significantly increased with two consecutive years of herbicide applications over a single application. Imazapyr applied during the second growing season proved to be the best treatment for improving pine growth, controlling competitive vegetation, minimizing pine mortality, and to remain effective when soils are saturated.

Title:

Soil nitrogen dynamics as an indicator for longleaf pine restoration

Author:

McCaskill, G. L.

Jose, S.

Chauhan, A.

Ogram, A. V.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Assessing the status of soil nutrients with their corresponding microbial communities provides important information about degraded soils during the restoration of coastal wet pine forests. Net nitrogen mineralization, nitrogen-oxidizing bacteria (NOB), and soil microbial biomass were compared with patch-derived volume along a 110-year longleaf pine (Pinus palustris Mill.) chronosequence for identifying a trajectory and ecological benchmark during forest restoration. Net nitrogen mineralization rates decreased significantly in the maturing-aged, pine patches, driven by a larger drop in net nitrification. Net nitrification and abundance of NOB were higher in young pine patches compared to soils from the maturing (86–110 years) pine patches. Gross nitrate fluxes followed the nonfungal portion of the soil microbial biomass along the chronosequence, declining in 64-year-old pine patches. Microbial biomass peaked in patches 17–34 years of age, but significantly declined in the older patches. Fungal biomass leveled off without decline. Ammonium was the major source of nitrogen within the maturing pine patches as well as the wetland patches, indicating that ammonium maintains longleaf pine during growth-limiting conditions. Nitrate dominated during rapid tree growth, optimally in mesic conditions. The relative amounts of available ammonium to nitrate can be used to model nitrogen cycling in facultative-wetland pine forests of the coastal United States as soils alternate between wet and mesic conditions. A key restoration benchmark occurred after 86 years of pine development when pine patch growth rates slowed, with lower numbers of NOB, when the nonfungal biomass leveled off, and net nitrification rates are at a minimum, during pine maturation.

Title:

Information sources and extension delivery methods used by private longleaf pine landowners

Author:

Radhakrishna, R. B.

Nelson, L.

Franklin, R.

Kessler, G.

Year published:

2003

Publication Type:

Peer-reviewed literature

Title:

Frequently burned loblolly-shortleaf pine forest in the southeastern United States lacks the stability of longleaf pine forest

Author:

Matusick, G.

Hudson, S. J.

Garrett, C. Z.

Samuelson, L. J.

Kent, J. D.

Addington, R. N.

Parker, J. M.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

In recent decades, conservation objectives have driven changes to the management of some pine forests in the southeastern United States. Forest thinning and frequent burning of old-field and plantation pine forests have resulted in an open loblolly–shortleaf pine forest community which resembles the original longleaf pine forest. It is, however, unclear how the structure, composition, and function of the loblolly–shortleaf forest compare to natural longleaf pine forest, and whether it represents an alternative stable state, or simply a transitional state. Understanding the stability of open loblolly–shortleaf pine forest is critical, particularly because several threatened and endangered species are now reliant on it for habitat. The structure and composition of loblolly–shortleaf forest and natural longleaf pine forest were compared using data from permanent forest plots at Fort Benning, Georgia, USA. To assess the stability of the loblolly–shortleaf pine forest and determine whether it is an alternative stable or transitional state, the LANDIS-II forest landscape simulation model was used to simulate changes in forest type cover under no disturbance, and a frequent-fire regime at Fort Benning. Under both management scenarios, nearly all loblolly–shortleaf pine forest converted to mixed hardwood forest over the course of the simulation, with most conversion occurring within 60 yr. In contrast, longleaf pine forest cover increased under frequent fire. Several important structural and compositional differences may have contributed to the instability of loblolly–shortleaf pine forest compared to longleaf pine forest. These include, among other factors, higher densities of resprouting hardwood trees and shrubs in loblolly–shortleaf pine forest, including sweetgum, a resilient broadleaf species capable of transforming ecosystem structure. These results highlight the instability of the open loblolly–shortleaf pine forest community and confirm that is a transitional state, destined for mixed hardwood forest in the coming decades under either no disturbance or frequent fire alone. Future forest planning should consider an active transition from the loblolly–shortleaf pine forest in the coming decades if open pine forest is to be conserved for wildlife and conservation objectives.

Title:

Breeding bird response to midstory hardwood reduction in Florida sandhill longleaf pine forests

Author:

Provencher, L.

Gobris, N. M.

Brennan, L. A.

Gordon, D. R.

Hardesty, J. L.

Year published:

2002

Publication Type:

Peer-reviewed literature

Abstract:

The dramatic loss and degradation of longleaf pine (Pinus palustris) forests in the southeastern United States have contributed to the declines of several bird species associated with this ecosystem. We examined breeding bird response to habitat restoration in longleaf pine sandhill forests of northwest Florida, USA. We compared habitat variables and abundance of breeding birds among 3 hardwood reduction techniques (prescribed spring burning, herbicide application, mechanical felling-girdling) and maintenance of fire exclusion (control). We also examined abundance of breeding birds in fire-maintained, non-experimental reference sites as a means to gauge management success based on similarity analysis. All 3 hardwood reduction methods decreased midstory hardwoods and canopy cover, and increased herbaceous cover compared with fire-suppressed control plots, but had little effect on longleaf pine basal area. Midstory hardwood reduction methods increased the similarity of the breeding bird species assemblages to those found in the reference plots, compared with the fire-excluded control plots. Species that most strongly contributed to the similarity between the hardwood reduction and the reference plots were, in decreasing order of importance: red-cockaded woodpecker (Picoides borealis), red-headed woodpecker (Melanerpes erythrocephalus), tufted titmouse (Baeolophus bicolor), and brown-headed nuthatch (Sitta pusilla). Depending on the similarity index used, additional but weaker contributors to the similarity between the hardwood reduction and the reference plots were northern cardinal (Cardinalis cardinalis), Bachman's sparrow (Aimophila aestivalis), and Carolina chickadee (Poecile carolinensis). Species associated with hardwoods (e.g., tufted titmouse, northern cardinal, Carolina chickadee) contributed to greater similarity of the reference condition by decreasing in abundance after hardwood reduction, whereas open-habitat species increased in numbers, compared with birds on the fire-excluded control plots. Only the detection rates of cardinals and Carolina chickadees were not different among hardwood reduction methods. Two notable species of concern that increased in all hardwood reduction plots compared with the control, but were not strong contributors of the similarity to the reference condition, were northern bobwhite (Colinus virginianus) and southeastern American kestrel (Falco sparverius paulus). Our results suggest that these management methods were beneficial to landbirds characteristic of fire-maintained longleaf pine sandhills in northwest Florida. However, northern bobwhites and Bachman's sparrows may require more intensive management than red-cockaded woodpeckers, such as shorter burn intervals, as these species depend directly on ground cover vegetation. We recommend prescribed spring burning as the most economical and ecologically desirable method for managing breeding bird habitat in longleaf pine sandhill forests.

Title:

Susceptibility of longleaf pine roots to infection and damage by four root-inhabiting ophiostomatoid fungi

Author:

Matusick, G.

Eckhardt, L. G.

Somers, G. L.

Year published:

2010

Publication Type:

Peer-reviewed literature

Abstract:

Restoration of longleaf pine-dominated uplands is common on many public and private lands throughout the southeastern United States. The once dominant longleaf pine ecosystem is important to many now-threatened and endangered plant and animal species, and land managers are increasing efforts to reestablish this fire-dependent forest. Unfortunately, tree mortality in longleaf pine has been observed following attempts to re-introduce prescribed fire. Root-inhabiting ophiostomatoid fungi and their insect vectors have invaded roots of symptomatic longleaf pine. Although, the relationship between ophiostomatoid fungi and longleaf pine roots is poorly understood. In order to assess the pathogenicity and virulence of four ophiostomatoid fungi to longleaf pine, trees within two broad age classes (20–30 and 40–60 years) were used for root inoculations during the fall of 2006 and 2007 along with the spring of 2007 and 2008. All fungal species consistently caused resin-filled, discolored lesions on the phloem surface extending to the xylem. The successful inoculation of healthy longleaf pine roots confirms the pathogenicity of Grosmannia huntii, Leptographium procerum, Leptographium serpens, and Leptographium terebrantis. G. huntii caused the largest lesions, including 22.20 cm2, 13.37 cm2, and 9.21 cm2 larger than L. procerum, L. terebrantis, and L. serpens respectively. In contrast, L. procerum caused significantly smaller lesions than all other fungi, including 8.65 cm2 smaller than L. terebrantis and 10.69 cm2 smaller than L. serpens. Restoration efforts of longleaf pine may be affected by fungal root infection in the future. Future studies should focus on the interactions between stress factors associated with longleaf pine to define more clearly the ecological role of root-inhabiting ophiostomatoid fungi in the ecosystem.

Title:

Historic land use influences contemporary establishment of invasive plant species

Author:

Mattingly, W. B.

Orrock, J. L.

Year published:

2013

Publication Type:

Peer-reviewed literature

Abstract:

The legacy of agricultural land use can have widespread and persistent effects on contemporary landscapes. Although agriculture can lead to persistent changes in soil characteristics and plant communities, it remains unclear whether historic agricultural land use can alter the likelihood of contemporary biological invasions. To understand how agricultural land-use history might interact with well-known drivers of invasion, we conducted factorial manipulations of soil disturbance and resource additions within non-agricultural remnant sites and post-agricultural sites invaded by two non-native Lespedeza species. Our results reveal that variation in invader success can depend on the interplay of historic land use and contemporary processes: for both Lespedeza species, establishment was greater in remnant sites, but soil disturbance enhanced establishment irrespective of land-use history, demonstrating that contemporary processes can help to overcome legacy constraints on invader success. In contrast, additions of resources known to facilitate seedling recruitment (N and water) reduced invader establishment in post-agricultural but not in remnant sites, providing evidence that interactions between historic and contemporary processes can also limit invader success. Our findings thus illustrate that a consideration of historic land use may help to clarify the often contingent responses of invasive plants to known determinants of invasibility. Moreover, in finding significantly greater soil compaction at post-agricultural sites, our study provides a putative mechanism for historic land-use effects on contemporary invasive plant establishment. Our work suggests that an understanding of invasion dynamics requires knowledge of anthropogenic events that often occur decades before the introduction of invasive propagules.

Title:

Longleaf pine and oak responses to hardwood reduction techniques in fire-suppressed sandhills in northwest Florida

Author:

Provencher, L.

Herring, B. J.

Gordon, D. R.

Rodgers, H. L.

Tanner, G. W. W.

Hardesty, J. L.

Brennan, L. A.

Litt, A. R.

Year published:

2001

Publication Type:

Peer-reviewed literature

Abstract:

Restoring fire-suppressed longleaf pine (Pinus palustris Mill.) sandhill communities often includes reducing hardwood structure before re-establishing maintenance fire regimes. Using a complete randomized block design, we compared the effects of three hardwood reduction techniques (spring burning, application of the ULW form of herbicide hexazinone, chainsaw felling/girdling) and a no-treatment control on oak and longleaf pine densities in fire-suppressed sandhills at Eglin Air Force Base, FL. Treatments were applied in the spring and summer of 1995. Felling/girdling and herbicide plots were also burned for fuel reduction from March to April in 1997. Frequently burned, high-quality sandhill plots were sampled to establish reference conditions. Pre-treatment diameter distributions of oaks followed a negative-exponential curve in all treatments, but were flat with low tree densities in reference plots. Oak densities were significantly reduced in the herbicide and felling/girdling plots in 1995. Compared to the controls, growing season fire topkilled up to 20% more hardwoods among smaller trees in 1995, but this value increased to approximately 50% after 1996. IN all years, the greatest reduction of oak juvenile density ()<1.4 m high) was caused by herbicide application. Control plots contained significantly fewer oak juveniles than the burn and felling/girdling plots. Reference plots contained the lowest and most variable oak juvenile densities. Size distributions of longleaf pine across all plots were bimodal with modes at 0-4.9 and 25-29.9 cm in diameter. The highest mode was at 0-4.9 cm in treatment plots and at 25-29.9 cm in reference plots. Only fire quantitatively changed the distributions by the attrition of the smallest trees >1.4 m high in all years. Fire caused approximately 50% decreases in longleaf pine juvenile (<1.4 m high) density in 1995 and 1997, median juvenile densities converged to 5-6 stems/200 m2 in all treatments, including the control. Juvenile densities were slightly higher and more variable in reference plots than in treatments. In 1997, fuel reduction burns in the herbicide and felling/girdling plots decreased densities of recently germinated longleaf pines to <5 seedling/ 20 m2 , a 90% decrease compared to 1996 densities. Seedling densities dropped by approximately 50% in control and burn plots, although these sites received no manipulations after 1995. Seedling densities only decreased by 22% in reference plots (205 seedlings/20 m2 in 1996) which did experience some fires.

Title:

Incentives for biodiversity conservation beyond the best management practices: are forestland owners interested

Author:

Matta, J. R.

Alavalapati, J. R. R.

Mercer, D. E.

Year published:

2009

Publication Type:

Peer-reviewed literature

Abstract:

With the growing recognition of the role of environmental services rendered by private lands, landowner involvement has become a critical component of landscape-level strategies to conserve biodiversity. In this paper, we examine the willingness of private forest owners to participate in a conservation program that requires adopting management regimes beyond the existing requlations for the silvicultural best management practices. Results from a multinomial logit model indicate both program attributes and landowner characteristics significantly influencing participation. While the mean incentive payment necessary to induce participation is $95.54 per ha per year, this amount varied among respondents with different forest ownership objectives 

Title:

Why does longleaf pine have low susceptibility to southern pine beetle

Author:

Martinson, S.

Hofstetter, R. W.

Ayres, M. P.

Year published:

2007

Publication Type:

Peer-reviewed literature

Abstract:

Pine forests throughout the world are subject to disturbance from tree-killing bark beetles, but pine species differ in their susceptibilities. In the southeastern U.S., Pinus palustris suffers far less mortality from the southern pine beetle, Dendroctonus frontalis, than do its sympatric congeners. We tested the commonly invoked hypothesis that P. palustris has relatively low susceptibility because it has higher oleoresin flow than other pines, especially P. taeda. However, seven studies in three states over six years refuted the hypothesis that P. palustris and P. taeda differ in their constitutive resin flow or in their capacity to replace resin depleted by either experimental wounding or natural beetle attacks. Additionally, surveys of natural beetle attacks revealed that P. taeda and P. palustris were equally likely to be attacked and killed when they co-occurred in front of growing infestations. Thus, the relative susceptibility of these two species changes with the spatial scale at which they are mixed, and the strong landscape-scale pattern of low mortality in P. palustris is not because individual trees are physiologically less susceptible. Ultimately, the conspicuous differential impact of D. frontalis on P. taeda and P. palustris may be the product of coevolution between tree defenses and beetle behavior.

Title:

Wild turkey habitat use in frequently-burned pine savanna

Author:

Martin, J. A.

Palmer, W. E.

Juhan, S. M.

Carroll, J. P.

Year published:

2012

Publication Type:

None

Abstract:

Managing pine (Pinus spp.) savanna through frequent use of prescribed fire and selective harvest of off-site hardwoods in the uplands is appropriate for many declining wildlife species, but may be incompatible with published recommendations for wild turkeys (Meleagris gallopavo). Therefore, we investigated breeding season habitat use of radio-tagged wild turkeys (n = 78) in a frequently burned pine savanna system in southwest Georgia during 2003–2005. Ground story vegetation structure and composition in pine savannas change rapidly following fire such that categorical (i.e., burned vs. unburned) habitat selection analyses does not depict the fine scaled time-dependent relationships; therefore, we analyzed turkey selection of savanna on a seasonal and continuous scale. From a seasonal standpoint, pine savanna habitat-type were selected by gobblers, but used less than availability by hens. However, selection of pine savanna was influenced by time since fire; hens more likely selected pine savannas burned within 1.4 years whereas gobblers selected pine savannas burned within 1.6 years. Hens also selected hardwood drains whereas gobblers demonstrated proportional use of these habitats. Selection of pine savannas by wild turkeys was dependent on application of prescribed burning <2 years and suggests that previous recommendations for longer burning frequencies are too long to balance turkey habitat needs with those of a suite of declining birds associated with pine savanna ecosystems.

Title:

Effects of hardwood reduction techniques on longleaf pine sandhill vegetation in northwest Florida

Author:

Provencher, L.

Herring, B. J.

Gordon, D. R.

Galley, K. E. M.

Tanner, G. W. W.

Hardesty, J. L.

Brennan, L. A.

Year published:

2001

Publication Type:

Peer-reviewed literature

Abstract:

We tested whether the intensity of hardwood mid-story reduction causes commensurate improvements of herbaceous groundcover in fire-suppressed Pinus palustris (longleaf pine) sandhills. Using a complete randomized block design, we compared the effects of three hardwood reduction techniques (spring burning, application of the ULW form of herbicide hexazinone, chainsaw felling/girdling) and a no-treatment control on plant species richness, and on life form and common species densities at Eglin Air Force Base, Florida, U.S.A., from 1995 to 1998. ULW and felling/girdling plots were burned for fuel reduction two years after initial treatment application. We also sampled the same variables in frequently-burned reference sandhills to establish targets for restoration. Spring burns achieved partial topkill of oaks (17.6-41.1% from 1995 to 1998) compared to reductions of 69.1-94% accomplished by ULW and of 93.2-67.8% by felling/girdling treatments. We predicted that plant species richness and densities of herbaceous groundcover life forms would increase according to the percent hardwood reductions. Predictions were not supported by treatment effects for species richness because positive responses to fire best explained increases in plant richness, whereas ULW effects accounted for the largest initial decreases. Legumes, non-legume forbs, and graminoids did not respond to treatments as predicted by the hypothesis. Again, positive responses to fire dominated the results, which was supported by greater herbaceous densities observed in reference plots. Overall, we found that the least effective and least expensive hardwood midstory reduction method, fire, resulted in the greatest groundcover improvements as measure by species richness and herbaceous groundcover plant densities.

Title:

Ant community change across a ground vegetation gradient in north Florida’s longleaf pine flatwoods

Author:

Lubertazzi, D.

Tschinkel, W. R.

Year published:

2003

Publication Type:

Peer-reviewed literature

Abstract:

Ant communities in longleaf pine habitats are poorly known and hence the naturally occurring ant assemblages of a large portion of southeastern North America are not well understood. This study examined the diverse ant community found in the longleaf pine flatwoods of north Florida and tested how ant diversity changes along a herbaceous ground cover gradient. Restoring the ground cover to its original floral composition is an important focus of longleaf pine conservation and hence it is important to understand how native faunal communities vary with ground cover variation. Using 4 sampling methods, we characterized the ant community and analyzed its within habitat variation among 12 study sites. We found the highest plot species richness (55 species) and within-habitat species richness (72 species) ever recorded for North American ants. The ants formed three distinct communities. The low-diversity arboreal and subterranean assemblages varied little across forest stands while the diversity of the species-rich ground foraging ant community was negatively correlated with percent herbaceous cover. The imported fire ant, Solenopsis invicta (monogyne form), was unexpectedly found to be abundant in high herbaceous cover sites. Floral restoration of the pine flatwoods, which is increasing the proportion of herbaceous cover, is likely to cause an increase in the abundance of the imported fire ant.

Title:

The path back: oaks (Quercus spp.) facilitate longleaf pine (Pinus palustris) seedling establishment in xeric sites.

Author:

Loudermilk, E. L.

Hiers, J. K.

Pokswinski, S. M.

O'Brien, J. J.

Barnett, A.

Mitchell, R. J.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Understanding plant–plant facilitation is critical for predicting how plant community function will respond to changing disturbance and climate. In longleaf pine (Pinus palustris Mill.) ecosystems of the southeastern United States, understanding processes that affect pine reproduction is imperative for conservation efforts that aim to maintain ecosystem resilience across its wide geographic range and edaphic gradients. Variation in wildland fire and plant–plant interactions may be overlooked in “coarse filter” restoration management, where actions are often prescribed over a variety of ecological conditions with an assumed outcome. For example, hardwood reduction techniques are commonly deemed necessary for ecological restoration of longleaf pine ecosystems, as hardwoods are presumed competitors with longleaf pine seedlings. Natural regeneration dynamics are difficult to test experimentally given the infrequent and irregular mast seed events of the longleaf pine. Using a long-term, large-scale restoration experiment and a long-term monitoring data site at Eglin Air Force Base, Florida (USA), this study explores the influence of native fire-intolerant oaks on longleaf regeneration. We test for historical observations of hardwood facilitation against the null hypothesis of competitive exclusion. Our results provide evidence of hardwood facilitation on newly germinated longleaf pine seedlings (<2 yr old) after two mast seeding events (1996, 2011). Using regression-tree and Kaplan–Meier survival analyses, we found that deciduous oak midstory density was the most significant variable associated with longleaf pine seedling survival rates in the first 2 yr after germination. We found that as few as 43 oak midstory stems ha−1 were sufficient to facilitate seedling survival, but as many as 1400 stems ha−1 maintained facilitation without competitive exclusion of seedlings. We found that 1.5-yr- old pine seedlings were more moisture stressed under more open canopy conditions when compared to those immediately adjacent to a midstory oak canopy. Recognition that deciduous oaks are important facilitators of longleaf seedling establishment on xeric sites represents a significant departure from conventional wisdom and current management practices that has largely focused on competitive exclusion. This points to a critical role of a deciduous oak midstory of moderate densities for long-term ecosystem resilience in xeric longleaf pine ecosystems in light of climate uncertainty.

Title:

Longleaf pine (pinus palustris) and hardwood dynamics in a fire-maintained ecosystem: a simulation approach

Author:

Loudermilk, E. L.

Cropper, W. P.

Mitchell, R. J.

Lee, H.

Year published:

2011

Publication Type:

Peer-reviewed literature

Title:

Enhancing Bachman’s sparrow habitat via management of red-cockaded woodpeckers

Author:

Plentovich, S.

Tucker, J.

Holler, N. R.

Hill, G. E.

Year published:

1998

Publication Type:

Peer-reviewed literature

Abstract:

Bachman's sparrows (Aimophila aestivalis) and red-cockaded woodpeckers (Picoides borealis) use mature pine woodlands characterized by well-spaced pines, an open midstory, and a dense understory of grasses and forbs. Populations of the Bachman's sparrow began declining in the 1930s, with both a dramatic retraction in geographic distribution and the extinction of many local populations. Current land management practices in the southeastern United States often focus on the habitat requirements of the red-cockaded woodpecker without considering other species with similar habitat requirements (i.e., Bachman's sparrow). We examined habitat requirements of the Bachman's sparrow on Eglin Air Force Base, Florida, to determine if management practices directed at recovery of red-cockaded woodpeckers are providing Bachman's sparrows with suitable habitat. Comparisons between active red-cockaded woodpecker clusters occupied (n = 8) and unoccupied (n = 13) by Bachman's sparrows showed that Bachman's sparrows selected areas with a dense understory of grasses and sparse midstory vegetation. Areas suitable for red-cockaded woodpeckers were not always suitable for Bachman's sparrows. Red-cockaded woodpeckers appear more tolerant of a hardwood midstory and do not require a dense cover of grasses and forbs. Prescribed burning is key for development and maintenance of the dense herbaceous understory preferred by Bachman's sparrow. In areas managed for red-cockaded woodpeckers, frequent (3-5 yr) burning early in the growing season appears the best way to increase habitat suitability for Bachman's sparrows.

Title:

Stand risk rating for the southern pine beetle: integrating pest management with forest management

Author:

Lorio, P. L.

Mason, G. N.

Autry, G. L.

Year published:

1982

Publication Type:

Peer-reviewed literature

Abstract:

Stand risk rating for the southern pine beetle. Dendroctonus frontalis Zimm., is a first step toward dealing with a serious but sporadic insect problem. Two approaches, one utilizing readily available resource data, the other employing data obtained from aerial photographs, illustrate application of current knowledge to meet the protection needs of resource management--the primary role of integrated pest management. During a 36-month period in Louisiana, high-risk stands accounted for 13.4 infestations per 1,000 acres, four times the rate of low-risk stands; in Texas high-risk stands accounted for 9.9 infestations per 1,000 acres during 1973-1978, almost five times the number for low.

Title:

Pyrogenic fuels produced by savanna trees can engineer humid savannas

Author:

Platt, W. J.

Ellair, D. P.

Huffman, J. M.

Potts, S. E.

Beckage, B.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Natural fires ignited by lightning strikes following droughts frequently are posited as the ecological mechanism maintaining discontinuous tree cover and grass‐dominated ground layers in savannas. Such fires, however, may not reliably maintain humid savannas. We propose that savanna trees producing pyrogenic shed leaves might engineer fire characteristics, affecting ground‐layer plants in ways that maintain humid savannas. We explored our hypothesis in a high‐rainfall, frequently burned pine savanna in which the dominant tree, longleaf pine (Pinus palustris), produces resinous needles that become highly flammable when shed and dried. We postulated that pyrogenic needles should have much greater influence on fire characteristics at ground level, and hence post‐fire responses of dominant shrubs and grasses, than other abundant fine fuels (shed oak leaves and grass culms). We further reasoned that these effects should increase with amounts of needles. We managed site conditions that affect fuels (time since fire, dominant vegetation), manipulated amounts of needles in ground‐layer plots, prescribed burned the plots, and measured fire characteristics at ground level. We also measured characteristics of ground‐layer oaks and grasses before, then 2 and 8 months after fires. We tested our hypotheses regarding effects of pyrogenic pine fuels on fire characteristics and vegetation regrowth and explored direct and indirect effects of fuels on fire characteristics and vegetation using a structural equation model. Pine needles influenced fire characteristics, elevating maximum temperature increases, durations of heating above 60°C, and fine fuel consumption considerably above measurements when fuels only included other savanna plants. Presence of pine needles depressed post‐fire numbers of oak stems and grass culms, especially in the interior of grass genets, as well as post‐fire flowering of grasses. The structural equation model indicated strong direct and indirect pathways from pine needles to post‐fire responses of oaks and grasses. The experimental field tests of hypotheses, bolstered by structural equation modeling, indicate pyrogenic fine fuels modify characteristics of prescribed fires at ground level, negatively affecting dominant ground‐layer oaks and grasses. Frequent fires fueled by pyrogenic needles should maintain humid savannas and generate spatial pyrodiversity that affects composition and dynamics of pine savanna ground‐layer vegetation.

Title:

Growth-differentiation balance: a basis for understanding southern pine beetle-tree interactions

Author:

Lorio, P. L.

Year published:

1986

Publication Type:

Peer-reviewed literature

Abstract:

Interrelationships between the southern pine beetle (SPB), Dendroctonus frontalis Zimm.) and its host pines are explained in terms of the growth-differentiation balance concept.A general hypothesis is proposed based on growth-differentiation balance in southern pines (radial growth of stems versus synthesis and yield of oleoresin) and seasonal activity of the SPB based on knowledge from experimentation and observations reported in the literature.The spring appears to be particularly favorable for successful SPB attack because of the strong demand for available photosynthates by growth processes at that time, whereas, in the summer, strong resin flow increases the potential resistance of trees to attack. Growth - differentiation balance provides a basis for understanding SPB-tree interactions, a rationale for commonly experienced problems in identifying consistent precursors to SPB outbreaks, and a philosophical basis for future research.The concept has potential application to other bark beetle-host conifer relationships.

Title:

Comparison of gopher tortoise (Gopherus polyphemus) habitats in young slash pine and old longleaf pine areas of southern Mississippi

Author:

Lohoefener, R.

Lohmeier, L.

Year published:

1981

Publication Type:

Peer-reviewed literature

Title:

The population dynamics of a long-lived conifer (Pinus palustris)

Author:

Platt, W. J.

Evans, G. W.

Rathbun, S. L.

Year published:

1988

Publication Type:

Peer-reviewed literature

Title:

Insect pollinators of three rare plants in a Florida longleaf pine forest

Author:

Pitts-Singer, T. L.

Hanula, J. L.

Walker, J. L.

Year published:

2002

Publication Type:

Peer-reviewed literature

Abstract:

As a result of human activity, longleaf pine (Pinus palustris Miller) forests in the southern United States have been lost or drastically altered. Many of the plant species that historically occupied those forests now persist only as remnants and are classified as threatened or endangered. In order to safeguard such species, a better understanding of their pollination ecology is needed. We identified insect visitors and potential pollinators of Harperocallis fluva (McDaniel) (Amaryllidaceae), Macbridea alba Chapman (Lamiaceae) and Scutellaria floriduna Chapman (Lamiaceae) that occur in longleaf pine habitat on the Apalachicola National Forest in Florida. We observed that potential pollinators of H. fluva were Halictidae, of M. alba were bumble bees (Apidae: Bombus), and of S. floridana were Megachilidae and Halictidae. However, the rates at which these insects visited the flowers were very low. Our results raise important concerns about how forest management practices affect the survival of rare plants, as well as their pollinators.

Title:

Comparing morphology and physiology of southeastern US Pinus seedlings: implications for adaptation to surface fire regimes

Author:

Pile, L. S.

Wang, G. G.

Knapp, B. O.

Liu, G.

Yu, D.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Key message The suite of traits expressed as seedlings by coastal and mountain longleaf pine and south Florida slash pine suggest they can survive fire in the seedling stage. In contrast, loblolly pine and typical slash pine tolerate fire when mature but do not exhibit traits that allow them to survive fire when young, representing a different strategy for survival in frequently burned communities. Context Fire is an important driver in the distribution and abundance of southern US pine species, and seedling fire tolerance often determines individual survival under frequent fire regimes. Aims We investigated seedling growth, biomass allocation, needle distribution, bark thickness, and total non-structural carbohydrate (TNC) storage in taproots and related them to the expression of fire-tolerance for five species or types, including loblolly pine (Pinus taeda L.), two longleaf pine (P. palustris Mill.) types representing two distinct ecological communities (coastal and mountain) and two slash pine (P. elliottii Englem.) varieties. Methods We analyzed the relationship of seedling growth, biomass characteristics, and total non-structural carbohydrate storage between species by using analysis of variance. Results Both coastal and mountain longleaf pines had thick bark, long, densely arranged needles, and a grass-stage. South Florida slash pine shared the same suite of traits but, contrary to previous reports, displayed reduced height growth rather than a grass-stage. In contrast, loblolly pine and typical slash pine had faster height growth, more branching, lower needle density, and thinner bark. Both longleaf pines and south Florida slash pine also had higher TNC storage in taproots than either loblolly or typical slash pines. Conclusion The relative strength of expression of these fire adaptation traits among the five species types generally matches the fire-return intervals associated with each species’habitat, suggesting the importance of fire regimes in determining the distribution and abundance of the studied species.

Title:

Estimating resilience across landscapes

Author:

Peterson, G. D.

Year published:

2002

Publication Type:

Peer-reviewed literature

Abstract:

Although ecological managers typically focus on managing local or regional landscapes, they often have little ability to control or predict many of the large-scale, long-term processes that drive changes within these landscapes. This lack of control has led some ecologists to argue that ecological management should aim to produce ecosystems that are resilient to change and surprise. Unfortunately, ecological resilience is difficult to measure or estimate in the landscapes people manage. In this paper, I extend system dynamics approaches to resilience and estimate resilience using complex landscape simulation models. I use this approach to evaluate cross-scale edge, a novel empirical method for estimating resilience based on landscape pattern. Cross-scale edge provides relatively robust estimates of resilience, suggesting that, with some further development, it could be used as a management tool to provide rough and rapid estimates of areas of resilience and vulnerability within a landscape.

Title:

The historical and current distribution of the eastern indigo snake (Drymarchon couperi)

Author:

Enge, K. M.

Stevenson, D. J.

Elliot, M. J.

Bauder, J. M.

Year published:

2013

Publication Type:

Peer-reviewed literature

Abstract:

The eastern indigo snake (Drymarchon couperi) historically occurred in southern Mississippi and Alabama, Georgia, and Florida. old reports from South Carolina are not thought to be credible. naturally occurring populations likely no longer occur in Mississippi and Alabama, and populations elsewhere are of conservation concern. however, there have been no large-scale efforts to determine the historical and current distributions of the eastern indigo snake across its entire range. Toward this end, we obtained records of eastern indigo snakes by: (1) searching databases, the literature, and U.S. museum collections; (2) soliciting sightings from qualified individuals via e-mail and questionnaires; and (3) conducting visual-encounter surveys in Georgia. in southeastern and south-central Georgia, we documented 379 recent (2001−2012) records from 29 counties and from 26 public or conservation lands (≥ 100 ha in area) in 18 counties. in Florida, we documented 595 recent (2001−2012) records from 46 counties and from 154 public or conservation lands ≥ 100 ha in area in 44 counties. The species still occurs throughout most of peninsular Florida except in urban areas and some agricultural regions, but recent records are scarce or absent in the panhandle and Florida keys. habitat loss, degradation, and fragmentation probably have impacted eastern indigo snake populations over much of their range, and a severe decline of gopher Tortoise (Gopherus polyphemus) populations in the Florida panhandle may account for the scarcity of eastern indigo snakes in this region because tortoise burrows are important overwintering refugia.

Title:

Xylem heating increases vulnerability to cavitation in longleaf pine

Author:

Lodge, A. G.

Dickinson, M. B.

Kavanagh, K. L.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Improved understanding of the physiological mechanisms of tree mortality following fires is important with the predicted increase in wildfires under climate change, as well as continued use of prescribed fire for forest management. Disruption of water transport in the xylem from exposure to the heat plume of a fire has been hypothesized as a mechanism of delayed tree mortality. This heat plume rapidly increases vapor pressure deficit in the canopy, increasing transpiration and tension on the xylem causing cavitation, thus reducing water transport and leading to eventual tree death.We aimed to increase understanding of the mechanisms behind such unintended mortality by determining whether branches and roots of longleaf pine are more vulnerable to cavitation when exposed to temperatures expected to occur during prescribed or wild fires. Additionally, we modeled expected branch cavitation under fire conditions based on measured cavitation vulnerability.We heated branch and root segments in a water bath to 41 ◦C and 54◦C and simulated the negative xylem water potentials experienced during exposure to a heat plume using a double-ended pressure chamber. When branches and roots were pressurized under elevated temperatures, xylem in both organs was more vulnerable to cavitation. In branches, as temperature was increased from 23 ◦C–54 ◦C, the pressure at which 50% conductivity was lost (P50) increased from−3.55MPa to −2.79 MPa, while in roots, P50 increased from −2.08 MPa to −1.36MPa.When the P50 values measured under elevated temperatures were included in plume and hydraulic models, branches were predicted to experience conditions leading to 50% loss of conductivity up to two meters higher into the canopy than under ambient temperatures. Overall, these results suggest that heating of branches and roots during fires can increase vulnerability to xylem cavitation, potentially leading to hydraulic disruption and delayed tree mortality.

Title:

Adult bobcat (Lynx rufus) habitat selection in a longleaf pine savanna

Author:

Little, A. R.

Conner, L. M.

Chamberlain, M. J.

Nibbelink, N. P.

Warren, R. J.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Background: Pine savannas are primarily managed with frequent prescribed fire (≤ 3 years) to promote diversity of flora and fauna, and to maintain open, park-like conditions needed by species such as the endangered red-cockaded woodpecker (Picoides borealis). However, a knowledge gap exists in our understanding of bobcat (Lynx rufus) habitat selection in longleaf pine savannas and research is warranted to direct our future management decisions. Methods: We examined bobcat habitat selection in a pine savanna managed with frequent fires at two spatial scales (i.e., study area boundary [hereafter, landscape scale]) and annual area of use [95% kernel density; local scale]), and assessed effects of prescribed fire on bobcat habitat selection. Specifically, we monitored 45 bobcats (16 males and 29 females) during 2001–2007. Results: We found differential habitat selection by sex. At the landscape scale, female bobcats were closer to mixed pine-hardwoods, young pine, and secondary roads, but farther from mature pine and hardwoods stands relative to males. We found no difference in selection of agriculture, shrub-scrub, and primary roads between sexes. At the annual area of use scale, female bobcats were closer to secondary roads, but farther from agriculture and shrub-scrub relative to males. We found no difference in selection of mature pine, mixed pine-hardwoods, hardwoods, young pine, and primary roads between sexes. Bobcats primarily selected for stands burned ≤ 1.1 years post-fire. Conclusions: Our results show that bobcats exploit a broad range of habitat types in pine landscapes managed with frequent fire and commonly use recently burned stands (≤ 1.1 year post-fire), suggesting prey in many areas of this system are at risk of bobcat predation. Additionally, we suggest land managers consider scale of selection by bobcats when developing habitat management strategies.

Title:

Utility of an instantaneous moisture meter for duff moisture prediction in long-unburned longleaf pine forests

Author:

Engber, E. A.

Varner, J. M.

Dugaw, C. J.

Quinn-Davidson, L. N.

Hiers, J. K.

Year published:

2013

Publication Type:

Peer-reviewed literature

Abstract:

Duff fires have been implicated in overstory mortality and soil heating in long-unburned pine forests. In the South’s punctuated climate, duff moisture can change rapidly, falling below moisture thresholds that protect trees or increasing after brief downpours. To date, managers lack an instantaneous measure of duff moisture, a hurdle to the implementation of prescribed burns. Here, we evaluate a low-cost tool, the Campbell Scientific Duff Moisture Meter (DMM) 600 (Campbell Scientific, Logan, UT), to estimate duff moisture content in the field. Comparisons of the DMM 600 outputs with paired oven-dried duff fuel samples revealed statistically significant differences, with DMM 600 moisture output explaining 54% of the variation in oven-dried moisture content. Comparisons with previously published data indicate that large variations in duff moisture calculations may predict a broad range of observed duff consumption and overstory tree mortality levels, limiting its applicability for some management objectives. DMM 600 outputs were only weakly correlated with Keetch-Byram drought index (R2 _ 0.30). In addition, we encountered some operational difficulties in prolonged field use. In spite of a few shortcomings, the DMM 600 provides a low-cost tool to assist in prescribed fires where deep forest floor fuels exist.

Title:

Longleaf pine (Pinus palustris Mill.) morphology and climate/growth responses along a physiographic gradient in North Carolina

Author:

Patterson, T. W.

Cummings, L. W.

Knapp, B. O.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Geographic differences in tree morphology and climate and growth responses of longleaf pine have been documented, yet how these differences vary at a larger scale has not. In this study, we documented changes in tree morphology and climate and radial growth responses of six longleaf pine (Pinus palustris Mill.) stands in three physiographic regions in North Carolina. We sampled from more than fifteen trees per stand and compared site- and regional-level total and latewood ring width values to temperature, precipitation, and drought. All morphological characteristics expressed a strong west–east gradient. Climate and radial growth response was strongest for the Sandhills region and then Piedmont and Coastal Plain regions. The distinct morphological characteristic gradient did not covary with climate and radial growth response, suggesting that additional environmental influences affect needle length, trunk diameter, and height.

Title:

Wood property maps showing wood variablity in mature longleaf pine: does getting older change juvenile tendencies

Author:

Eberhardt, T. L.

So, C.

Leduc, D. J.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Established illustrations of juvenile wood in pines depict a central core of wood, varying little by diameter or cambial age, to be nested within mature wood tapering to the upper portion of the stem; alternative illustrations show greater complexity in attributing variability within this central core of wood to its proximity to the crown and/or the maturity of the tree when the wood was formed. The present study addresses the degree to which different representations of juvenile wood are applicable to a sampling of 70-yr-old longleaf pine (Pinus palustris Mill.) trees. Wood property maps were derived from X-ray densitometry data gathered from tree disks taken at every 61 cm along each tree bole. Unique to the wood property maps herein is that the two cardinal directions of the data (north and south) were preserved, thus providing true full-stem profiles. Compared with maps reported for younger southern pines, the central core of low-density wood extending the length of the tree boles was noticeably wider at the midheight than at the lower and higher relative heights. Another difference was that the higher ring specific gravity (SG) values, particularly at the lower heights, did not extend all the way to the wood closest to the bark. Narrower ring width and higher ring SG values above the 3Q height, normally being wood features associated with higher wood quality, can be attributed to thematurity of the study trees. Altogether, the wood property maps and data comparisons were consistent with an alternative juvenile wood illustration proposing that all the wood at the base of the tree, comprised of juvenile corewood and juvenile outerwood, as being different from the majority of the tree wood, upward from a one-quarter relative height.

Title:

Wood variability in mature longleaf pine: defferences related to cardinal direction for a softwood in a humid subtropical climate

Author:

Eberhardt, T. L.

So, C.

Leduc, D. J.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Mature longleaf pine (Pinus palustris Mill.) trees were harvested to compare wood property data for opposing bark-to-pith wood strips representing the northern and southern cardinal (or compass) directions. For each of the ten 70-yr-old trees used in the study,wood property datawere compared at breast height (BH) and three relative heights: one-quarter height (1Q), midheight (MID), and three-quarter height (3Q). Scanning of the specimens by X-ray densitometry gave specific gravity (SG) profiles that were used to determine wood properties for comparison. No significant differences were determined for wood property data at BH, MID, or 3Q. However, data at 1Q showed higher ring SG (p ¼ 0.043) and percent latewood (p ¼ 0.018) for the northern side, although no differences were observed in the earlywood or latewood SG. This indicated that the higher ring SG for the northern direction results from a greater proportion of latewood. Partitioning the data into estimated juvenile-transition wood and mature wood zones demonstrated that the greater ring SGand percent latewood values in the northern direction occurredwithin the mature wood zone. Findings presented herein appear to provide the first demonstration of variation in wood properties with respect to cardinal direction for a pine species growing in a humid subtropical climate.

Title:

Collection of wood quality data by x-ray densitometry: a case study with three southern pines

Author:

Eberhardt, T. L.

Samuelson, L. J.

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

X-ray densitometry is a technique often used in tree growth and wood quality studies to incrementally measure density (specific gravity) along a radial strip of wood. Protocols for this technique vary between laboratories because of differences in species, equipment, tree age, and other factors. Here, the application of X-ray densitometry is discussed in terms of a case study specific to the southern pines, whereby loblolly (Pinus taeda L), longleaf (Pinus palustris Mill.), and slash (Pinus elliottii Engelm.) pine wood cores were analyzed using an automated system. Objectives of this study included an assessment of the potential impacts on wholecore wood quality data from wood core extraction and use of two different demarcation methods (threshold and inflection point) for the earlywood–latewood transition. Wood core extraction before X-ray densitometry showed minimal impact on the shapes of individual ring profiles, and whole-core wood quality data were essentially unchanged. An assessment of the inflection point method employed for determining the earlywood–latewood transition point in the X-ray densitometry data demonstrated that the growth ring profiles for the southern pines are not amenable to polynomial fitting. Indeed, in the southern pines, the earlywood–latewood transitions are as equally abrupt as the latewood–earlywood transitions. Accordingly, a threshold density deemed appropriate to define the onset of a growth ring would be equally appropriate to define the onset of latewood formation.

Title:

Rotation burning: a forage management system for longleaf pine-bluestem ranges

Author:

Duvall, V. L.

Whittaker, L. B.

Year published:

1964

Publication Type:

Peer-reviewed literature

Abstract:

In a Louisiana test, heavy utilization during growing seasons following fires applied at 3-year intervals improved forage palatability and nutritive content; the ensuing 2 years of lighter use restored plant vigor. Burning also top-killed brush and aided herbage growth by removing pine litter. Cows with calves gained weight throughout the growing season on rotation-burned grange.

Title:

Influences of grazing and fire on vegetation and soil of longleaf pine-bluestem range

Author:

Duvall, V. L.

Linnartz, N. E.

Year published:

1967

Publication Type:

Peer-reviewed literature

Abstract:

Herbage yield and density of cover were greater on moderately or heavily grazed than on ungrazed range. Botanical composition remained relatively constant under moderate use but changed markedly on ungrazed and heavily grazed ranges. Grazing compacted soils, but insufficiently fo impair herbage growth or accelerate erosion. Fire had little long-range effect.

Title:

Regional differences in habitat occupancy by Bachman’s sparrow

Author:

Dunning, J. B.

Watts, B. D.

Year published:

1990

Publication Type:

Peer-reviewed literature

Abstract:

Bachman's Sparrow (Aimophila aestivalis) has declined over much of its range in the last fifty years. To understand the role of habitat loss in this decline, we examined patterns of habitat occupancy by this species in two areas of South Carolina. At both sites we recorded relatively high densities of breeding sparrows in mature (>80 yr old) pine stands, and relatively low densities in young pine stands. Habitat occupancy varied between sites in clearcuts and middle-aged pine stands. Sparrows used areas with open understories and dense ground covers of grasses and forbs. Habitat occupancy differed between the two main study areas because these preferred vegetation characteristics were found in different habitats in the two areas. Timber management practices (especially burning rotations, site- preparation techniques, and thinning) have a strong effect on understory vegetation and, therefore, habitat suitability for the sparrow. Management practices that produce suitable habitat for Red-cockaded Woodpeckers (Picoides borealis) also provide habitat for Bachman's Sparrow. We believe that, even though the sparrow may use open habitats that appear to be relatively common, its habitat requirements are relatively strict, and rhat habitat loss may be an important factor in this species' population decline.

Title:

Fire effects on resprouting shrubs in headwaters of southeastern longleaf pine savannas

Author:

Drewa, P. B.

Platt, W. J.

Moser, E. B.

Year published:

2002

Publication Type:

Peer-reviewed literature

Abstract:

Woody plants in fire-frequented ecosystems commonly resprout from underground organs after fires. Responses to variation in characteristic~ of fire regimes may be a function of plant physiological status or fire intensity. Although these hypotheses have been explored for trees in southeastern longleaf pine (Pinus palustris) savannas, responses of other life forms and stages have not been studied. We examined effects of fire season Land frequency, geography, habitat, and underground organ morphology on resprouting of shrubs. In 1994, we located replicated sites, each containing two habitats, upslope savannas and downslope seepages, in Louisiana and Florida. Each site, which contained quadrats located along transects within a 30 X 60 m plot, was burned either during the dormant or growing season and then reburned similarly two years later. Maximum fire temperatures were measured, and densities of shrub stems were censused in quadrats before and after fires. Shrubs collectively resprouted more following dormant than growing-season fires, regardless of habitat or geographic region. After repeated dormant-season fires, collective densities in seepages of both regions and densities of root-crown-bearing shrubs in Florida seepages were greater than those initially and after repeated growing-ieason fires. Shrub responses were generally unrelated to fire temperatures, supporting the hypothesis that resprouting of shrubs may be more dependent on their physiological status at the time of fires. There was, nonetheless, an inverse relationship between collective and root-crownbearing shrub densities following repeated fires and maximum fire temperatures in Florida seepages. Anthropogenic dormant-season fires over many decades may have resulted in increases in shrub densities in longleaf pine savannas, especially seepages. Repeated growing-season fires, however, neither increased nor reduced densities of established shrubs. Long-term shifts in characteristics of fire regimes, even in fire-frequented habitats, may produce effects that are not reversible in the short term (<lo yr) by simply reintroducing prescribed fires that resemble those that occurred naturally during the growing season.

Title:

The vascular flora of Ichauway, Baker County, Georgia: a remnant longleaf/wiregrass ecosystem

Author:

Drew, M. B.

Kirkman, L. K.

Gholson, A. K.

Year published:

1998

Publication Type:

Peer-reviewed literature

Abstract:

The vascular flora of the Jones Ecological Research Center (Ichauway), a remnant longleaf pine/ wiregrass ecosystem located in the Coastal Plain of Georgia, was inventoried. High species richness and large numbers of rare and endemic plants are associated with the open, fire-maintained longleaf pine forests and associated depressional wetlands and riparian hardwood forests. The study identified 1,013 taxa in 466 genera and 134 families. The total includes 392 species that are the first record of occurrence for Baker County, Georgia. The Georgia Natural Heritage Program lists 25 of these species as endangered, rare, or of special concern in the state of Georgia, two of which, Lindera melissaefolium and Schwalbea americana, are listed as federally endangered. Ninety-three (9%) of the taxa are introduced.

Title:

The distribution of the eastern indigo snake, Drymarchon couperi, in Georgia

Author:

Diemer, J. E.

Speake, D. W.

Year published:

1983

Publication Type:

Peer-reviewed literature

Abstract:

A 2-year study was undertaken to survey the distribution of the eastern indigo snake (Drymarchon corais couperi) in Georgia and to characterize and delineate its habitat in the state. Data were gathered through questionnaires, follow-up interviews, intensive snake hunting, soil maps, vegetational analyses and satellite imagery. The majority of 511 sightings occurred in the Tifton Uplands of the Georgia Coastal Plain and were associated with deep, excessively drained, sandy soils along major streams. Winter sightings occurred almost exclusively on sandhills and in association with the burrows of the gopher tortoise (Gopherus polyphemus).

Title:

The ecology and management of the gopher tortoise in the southeastern United States

Author:

Diemer, J. E.

Year published:

1986

Publication Type:

Peer-reviewed literature

Abstract:

Recent research on the gopher tortoise (Gopherus polyphemus) has indicated its ecological importance, revealed reasons for its decline, and suggested management strategies. It is generally associated with the sandhill community but occurs in a variety of other natural and ruderal habitats. Limiting factors include well-drained sandy soil, adequate herbaceous food, and sunlit nesting sites. Tortoise densities and movements are related to herbaceous biomass. As the principal sandhill grazer, the gopher tortoise serves as a seed dispersal agent for native groundstory plants. The burrowing habits of the gopher tortoise return leached nutrients to the surface and the burrows provide refuges for many other species. Female gopher tortoises reach sexual maturity at 10-20 yr of age and produce a single annual clutch of about six eggs. Recruitment is reduced by heavy egg and hatchling predation. The major reasons for the decline of the gopher tortoise are habitat destruction, habitat degradation, and human predation. Recommended conservation mea- sures include prescribed burning of sandhill habitat, establishment of preserves, protection from over-harvest, restocking, and public education

Title:

Pine savanna plant community disassembly after fire suppression

Author:

Diaz-Toribio, M. H.

Carr, S.

Putz, F. E.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Biodiversity is being lost rapidly due to anthropogenic changes in land use, climate, and other environmental conditions. In fire-maintained ecosystems, altered fire regimes accelerate native species loss — community disassembly — and promote recruitment of fire-sensitive species. In this study, we ask whether fire suppression results in changes over time in functional trait composition of ground-layer species and whether these changes differ in longleaf pine savannas invaded by hardwoods from those invaded by sand pines. Location: Five Floridian locations on the southeastern coastal plain of the United States. At each location we selected a fire-maintained and fire-suppressed savanna and measured percent plant cover by ground-story species in 1,000 m2 plots. For 102 of these species, we measured 10 functional traits — height, growth form, specific leaf area, leaf dry matter content (LDMC), leaf water content, leaf ignition time, leaf mass consumed by fire, light compensation points (LCPs), non-structural carbohydrate concentrations in under-ground organs, and seed mass. Results: Fire exclusion was associated with reductions in both functional diversity and species richness. We identified 38 species exclusive to frequently burned sites: these species showed high LDMC values, high LCPs, high leaf mass consumed, and low leaf ignition time values. Lack of fire was associated with loss of 6 of the 12 C4 native grass species. Species and functional trait composition were affected by both time-since-fire and whether post-fire communities were invaded by broadleaved trees (Quercus spp. and Liquidambar styraciflua) or by sand pine (Pinus clausa). Conclusions: We demonstrated the effects of altered disturbance regimes on savanna plant species and functional trait composition. This trait-based approach advanced our understanding of how altered disturbance regimes can alter plant communities. Although 38 shade-intolerant and flammable native savanna species were absent by 10 years since fire, 12 such species persisted even 40 years after fire exclusion.

Title:

Interaction diversity maintains resiliency in a frequently distrubed ecosystem

Author:

Dell, J. E.

Salcido, D. M.

Lumpkin, W.

Richards, L. A.

Pokswinski, S. M.

Loudermilk, E. L.

O'Brien, J. J.

Dyer, L. A.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Frequently disturbed ecosystems are characterized by resilience to ecological disturbances. Longleaf pine ecosystems are not only resilient to frequent fire disturbance, but this feature sustains biodiversity. We examined how fire frequency maintains beta diversity of multi-trophic interactions in longleaf pine ecosystems, as this community property provides a measure of functional redundancy of an ecosystem. We found that beta interaction diversity at small local scales is highest in the most frequently burned stands, conferring immediate resiliency to disturbance by fire. Interactions become more specialized and less resilient as fire frequency decreases. Local scale patterns of interaction diversity contribute to broader scale patterns and confer long-term ecosystem resiliency. Such natural disturbances are likely to be important for maintaining regional diversity of interactions for a broad range of ecosystems.

Title:

Maximizing the monitoring of diversity for management activities: additive partitionaing of plant species diversitiy across a frequently burned system

Author:

Dell, J. E.

Pokswinski, S. M.

Richards, L. A.

Hiers, J. K.

Williams, B.

O'Brien, J. J.

Loudermilk, E. L.

Hudak, A. T.

Dyer, L. A.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Monitoring understory plant diversity is important, allowing managers to track current diversity status and trends both spatially and temporally at a landscape-scale. Improving precision in quantifying patterns in understory plant diversity improves efficiency in monitoring design and more accurate measures of success of management intervention over time. Patterns of species diversity are dependent upon the scale in which they are examined – an increase in small-scale diversity across a gradient can convert to a decrease in large-scale diversity across that same gradient. Using two extensive datasets including both mined historical data and supplemental experimental data, we performed an additive partitioning of plant diversity to elucidate the hierarchical spatial patterns of understory plant species richness, and independent measures of alpha and beta diversity in the species-rich longleaf pine ecosystem at Eglin Air Force Base in northwestern FL, USA. This analysis allowed us to identify the spatial scale that most effectively captures plant diversity to inform monitoring efforts by using measures of species turnover, specifically beta diversity. We found that while species richness and alpha diversity increased with spatial scale, beta diversity began to reach an asymptote at smaller (1m2) scales. Furthermore, we found the sampling effort at this 1m2 scale required as few as 60 plots to effectively estimate plant diversity within management blocks. While our results are attributable to Eglin AFB specifically, these scaling analyses can help to streamline monitoring efforts in other ecosystems that seek to elucidate the individual contributions of diversity components.

Title:

An arthodpod survival strategy in a frequently burned forest

Author:

Dell, J. E.

O'Brien, J. J.

Doan, L.

Richards, L. A.

Dyer, L.

Year published:

2017

Publication Type:

Peer-reviewed literature

Title:

Overstory-derived surface fuels mediate plant species diversity in frequently burned longleaf pine forests

Author:

Dell, J. E.

Richards, L. A.

O'Brien, J. J.

Loudermilk, E. L.

Hudak, A. T.

Pokswinski, S. M.

Bright, B. C.

Hiers, J. K.

Williams, B. W.

Dyer, L. A.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Frequently burned low-latitude coniferous forests maintain a high-diversity understory. Longleaf pine (Pinus palustris Mill.) forests and woodlands have exceptionally high diversity at fine scales and very frequent fire return intervals (1–3 yr). Furthermore, the positive association between high-frequency, low-intensity surface fires and high species richness in longleaf pine ecosystems is well documented but poorly understood. Recent studies have demonstrated additional linkages between specific fuel assemblages and fire intensity at small spatial scales. In this study, we build upon both patterns by using long-term datasets to examine the relationship between fire and specific fuel types, and how the combination of these two elements contributes to ground cover species diversity.We used 11 yr of monitoring data from longleaf pine forests at Eglin Air Force Base, Florida (USA), to parameterize a structural equation model that examines causal relationships between fuels and fire history on ground cover plant diversity. Overstory-derived fuels, including pine needle litter, pine cones, and other 10 and 100-h woody fuels, had the greatest positive impact on diversity in relatively open-canopied, frequently burned reference stands. A second model examined surface fuel components originating from the forest overstory as characterized by airborne light detection and ranging and found that pine needle litter was positively associated with canopy density. Our parameter estimates for causal relationships between easily measured variables and plant diversity will allow for the development of management models at the stand scale while being informed by fuels measured at the plot scale

Title:

Burn regime matters: a reivew of the effects of prescribed fire on vertebrates in the longleaf pine ecoystem

Author:

Darracq, A. K.

Boone, W. W.

McCleery, R. A.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

A clear understanding of how management influences vertebrate biodiversity is critical for the conservation of rare ecosystems, such as the longleaf pine (Pinus palustris) ecosystem in the southeastern United States. We used scientific literature to assess how vertebrate use of the longleaf pine ecosystem (High or low) differed in response to high (1–3 years), moderate (>3–5 years), and low (>5 years) burn frequencies. For all species combined, we found that the number of high use (HU) species associated with moderately burned forests (n = 140) was 22% and 33% greater than in high (n = 115) and low burn (n = 105) frequency forests, respectively. This pattern was most clear for Aves and Reptilia. Specifically, the number of HU species associated with moderate burn frequencies (Aves – n = 69; Reptilia – n = 36) was 21% and 25% greater for Aves and 56 and 63% greater for Reptilia than high (Aves – n = 57; Reptilia – n = 23) and low burn frequencies (Aves – n = 55; Reptilia – n = 22), respectively. We found no difference in the number of HU species across burn frequencies for Amphibia or Mammalia. For species considered longleaf pine specialists, across all vertebrate taxa the number of HU species was associated with areas of high and moderate burn frequencies. We posit that moderate burn frequencies had the greatest number of HU species because of requirements for multiple habitat types, structural diversity, and habitat components that are reduced in, or not provided by, areas with high burn frequencies. If conservation of specific longleaf pine specialists that rely on habitat created by high fire frequencies (e.g. Red-cockaded woodpeckers) is the objective, we suggest managing with high burn frequencies at the local scale. Conversely, if management objectives include maximizing wildlife diversity, managers should use a more variable fire regime across the landscape, from annual to less frequent 5 year burn intervals, to maintain localized patches of oaks and increase the compositional and structural diversity within the system.

Title:

Ongoing accumulation of plant diversity through habitat connectivity in an 18-year experiment

Author:

Damschen, E. I.

Brudvig, L. A.

Burt, M. A.

Fletcher, R. J.

Haddad, N. M.

Levey, D. J.

Orrock, J. L.

Resasco, J.

Tewksbury, J. J.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Deleterious effects of habitat fragmentation and benefits of connecting fragments could be significantly underestimated because changes in colonization and extinction rates that drive changes in biodiversity can take decades to accrue. In a large and well-replicated habitat fragmentation experiment, we find that annual colonization rates for 239 plant species in connected fragments are 5% higher and annual extinction rates 2% lower than in unconnected fragments. This has resulted in a steady, nonasymptotic increase in diversity, with nearly 14%more species in connected fragments after almost two decades. Our results show that the full biodiversity value of connectivity is much greater than previously estimated, cannot be effectively evaluated at short time scales, and can be maximized by connecting habitat sooner rather than later.

Title:

Corridors increase plant species richness at large scales

Author:

Damschen, E. I.

Haddad, N. M.

Orrock, J. L.

Tewksbury, J. J.

Levey, D. J.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

Title:

Survival and cause-specific mortality of female eastern wild turkeys in two frequently-burned longleaf pine savannas

Author:

Little, A. R.

Bensen, J. F.

Chamberlain, M. J.

Conner, L. M.

Warren, R. J.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine savannas have declined throughout the southeastern United States due to land-use change. Fortunately, natural resource professionals are currently restoring these ecologically and economically important savannas. Although efforts are underway to restore longleaf pine savannas, little information exists on female eastern wild turkey Meleagris gallopavo silvestris population dynamics in these systems. Therefore, we evaluated survival and cause-specific mortality of female eastern wild turkeys in two longleaf pine savannas in southwestern Georgia. We radio-marked 126 female wild turkeys during 2010–2013 and monitored their survival; 66 (52.4%) radio-marked females died during the study. We estimated causes of death for 37 mortality events with predation serving as the leading known cause of mortality, with 35.1% of mortalities attributed to mesocarnivore predation (e.g., bobcat Lynx rufus, coyote Canis latrans, and gray fox Urocyon cinereoargenteus) and 18.9% to great-horned owl Bubo virginianus predation. One female (2.7%) was hit by a vehicle. Seasonal survival estimates varied from a high during fall (Ŝ = 0.94; 95% CI: 0.86–1.00) to a low during spring (Ŝ = 0.76; 95% CI: 0.68–0.87). Survival of incubating females was 0.82 (95% CI: 0.71–0.93) and survival of nonincubating females was 0.67 (95% CI: 0.52–0.87). Annual survival was 0.55 (95% CI: 0.44–0.67). To ensure sustainable wild turkey populations in longleaf pine savannas, we suggest managers monitor relationships between survival and population productivity.

Title:

Habitat selection of wild turkeys in burned longleaf pine savannas

Author:

Little, A. R.

Chamberlain, M. J.

Conner, L. M.

Warren, R. J.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Frequent prescribed fire (3 yr) and selective harvest of off-site hardwoods are the primary restoration and management tools for pine (Pinus spp.) savannas in the southeastern United States. However, a knowledge gap exists in our understanding of eastern wild turkey (Meleagris gallopavo silvestris) habitat selection in longleaf pine savannas and research is warranted to direct our future management decisions. Therefore, we investigated habitat selection of female turkeys in 2 longleaf pine savanna systems managed by frequent fire in southwestern Georgia during 2011–2013. We observed differential habitat selection across 2 scales (study area and seasonal area of use) and 3 seasons (fall-winter: 1 Oct–30 Jan; pre-breeding: 1 Feb–19 Apr; and summer: 16 Jun–30 Sep). During fall-winter, turkeys selected mature pine, mixed pine-hardwoods, hardwoods, and young pine stands, albeit at different scales. During pre-breeding, turkeys selected for mature pine, mixed pine-hardwoods, hardwoods, young pine, and shrub-scrub, although at different scales. During summer, turkeys also demonstrated scale-specific selection but generally selected for mature pine, hardwoods, and shrub-scrub. Days-since-fire did not influence selection of stands managed by frequent fire (3 yr). In cases where female turkeys used pine-dominated stands (i.e., mature pine, young pine, and mixed pinehardwoods), selection was not influenced by days-since-fire; however, these results are at least partially due to a lack of longer burn rotations (>3 yr) on our study areas. We suggest land managers consider scale of selection by turkeys when developing habitat management strategies. In addition to creating early successional habitat conditions by using prescribed fire, we recommend managers retain hardwoods and recognize the importance of shrub-scrub cover to management of turkey populations in longleaf pine savannas.

Title:

Bioregional planning in central Georgia, USA

Author:

Dale, V. H.

Aldridge, M.

Arthur, T.

Baskaran, L.

Berry, M.

Chang, M.

Efroymson, R.

Garten, C.

Stewart, C.

Washington-Allen, R.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

Human influences in the five-county region around Fort Benning, Georgia, USA, have been long and intense. Only 4% of the native longleaf pine (Pinus palustris) forest remains intact. Besides the loss of species, habitats, and ecosystem services associated with longleaf pine forests, the environmental concerns of the region include air, water, and noise pollution. The mix of federal and private ownership in this region leads to complicated land-management issues that will likely become even more difficult as the city of Columbus continues its projected growth along the northern border of Fort Benning. To understand how anthropogenic developments affect the environment, we are developing a Regional Simulator (RSim) to project future developments and their impacts on environmental conditions. Using RSim, we can identify the potential effects of growth on noise and air pollution, water-borne nutrients, and habitats for focal species. Noise impacts are already large in the areas of current and projected urban growth for the region. This knowledge of potential futures allows options for environmental protection to be considered. A key lesson from this analysis is that regional simulation models are a cost-effective way to assess the long-term environmental implications of anthropogenic growth and development.

Title:

Understory vegetation indicators of anthropogenic disturbance in longleaf pine forests at Fort Benning, Georgia, USA

Author:

Dale, V. H.

Beyeler, S. C.

Jackson, B.

Year published:

2002

Publication Type:

Peer-reviewed literature

Abstract:

Environmental indicators for longleaf pine (Pinus palustris) ecosystems need to include some measure of understory vegetation because of its responsiveness to disturbance and management practices. To examine the characteristics of understory species that distinguish between disturbances induced by military traffic, we randomly established transects in four training intensity categories (reference, light, moderate, and heavy) and in an area that had been remediated following intense disturbance at Fort Benning, GA. A total of 134 plant species occurred in these transects with the highest diversity (95 species) in light training areas and the lowest (16 species) in heavily disturbed plots. Forty-seven species were observed in only one of the five disturbance categories. The variability in understory vegetation cover among disturbance types was trimodal ranging from less than 5% cover for heavily disturbed areas to 67% cover for reference, light, and remediated areas. High variability in species diversity and lack of difference in understory cover led us to consider life-form and plant families as indicators of military disturbance. Life-form successfully distinguished between plots based on military disturbances. Species that are Phanerophytes (trees and shrubs) were the most frequent life-form encountered in sites that experienced light infantry training. Therophytes (annuals) were the least common life-form in reference and light training areas. Chamaephytes (plants with their buds slightly above ground) were the least frequent life-form in moderate and remediation sites. Heavy training sites supported no Chamaephytes or Hemicryptophytes (plants with dormant buds at ground level). The heavy, moderate, remediated, and reference sites were all dominated by Cryptophytes (plants with underground buds) possibly because of their ability to withstand both military disturbance and ground fires (the natural disturbance of longleaf pine forests). Analysis of soils collected from each transect revealed that depth of the A layer of soil was significantly higher in reference and light training areas which may explain the life-form distributions. In addition, the diversity of plant families and, in particular, the presence of grasses and composites were indicative of training and remediation history. These results are supported by prior analysis of life-form distribution subsequent to other disturbances and demonstrate the ability of life-form and plant families to distinguish between military disturbances in longleaf pine forests.

Title:

The effects of the red imported fire ant on seed fate in the longleaf pine ecosystem

Author:

Cumberland, M. S.

Kirkman, L. K.

Year published:

2013

Publication Type:

Peer-reviewed literature

Abstract:

The natural patterns of myrmecochory are disrupted by the dominance of red imported fire ants (Solenopsis invicta) in the southeastern United States. This leads to questions about the role of fire ants as seed dispersers. We examined the fate of ant-dispersed seed in the longleaf pine ecosystem. First, we determined removal rates for a suite of common ground cover species. Then, we verified the final location of removed seeds by using a wax cast to examine nest contents, and locating dyed seeds deposited in trash piles on the ground surface. Finally, we determined if the germination rate of seeds deposited by fire ants was affected by ant dispersion. Fire ants were most attracted to elaiosome-bearing seed and collected nonelaiosome-bearing seed at a much lower rate. No seeds were found in the contents of wax castings of fire ant nest chambers, suggesting that seed is not stored within the nest. Of the dyed seeds that we presented to fire ants, 30—40 % were recollected in surface trash piles in the mound vicinity within 1 week following removal. Undiscovered seeds were considered destroyed or buried in foraging tunnels. A small percentage of the deposited seeds were able to germinate, but there was no difference in the percent germination between seeds manipulated by fire ants and the control. Low germination was likely due to a high percentage of immature seeds used in the study. Our findings support a growing body of evidence that fire ants facilitate the movement of seeds in the longleaf pine ecosystem.

Title:

Early tree growth, crop yields and estimated returns for an agroforestry trial in Goldsboro, North Carolina

Author:

Cubbage, F.

Glenn, V.

Mueller, J. P.

Robinson, D.

Myers, R.

Luginbuhl, J.

Myers, R.

Year published:

2012

Publication Type:

Peer-reviewed literature

Abstract:

A 17 acre (6.9 ha) agroforestry research and extension alley cropping trial was established at the Center for Environmental Farming Systems in Goldsboro, North Carolina in January 2007, with a randomized block design with five replications. Loblolly pine (Pinus taeda), longleaf pine (Pinus palustris) and cherrybark oak (Quercus pagoda) were planted in staggered rows, with each species planted for 140 ft (43 m) per replication. Crop land alleys of 40 ft or 80 ft (12.2–24.4 m) wide were left between the tree rows. Crops of soybeans (Glycine max) and corn (Zea mays) were planted in alternating years since establishment. As of 2011, survival rates were 93% for cherrybark oak, 88% for longleaf pine and 97% for loblolly pine. Average tree diameter at ground level was 1.0 in (2.5 cm) for cherrybark oak, 2.1 in (5.3 cm) for longleaf and 3.2 in (8.1 cm) for loblolly. Heights averaged 4.6 ft (1.4 m) for cherrybark oak, 5.2 ft (1.6 m) for longleaf pine and 10.4 ft (3.2 m) for loblolly pine. Growth, yield and economic projections for traditional timber production indicated that species volumes and values tracked the height and diameter relationships measured on the site. Loblolly pine had the largest projected internal rate of return, at 7.2%, followed by longleaf pine with pine straw harvests at 5.5%, longleaf without pine straw at 3.5% and cherrybark oak at 1.9%. There might be more loss in crop and silvopasture production with loblolly, however, and production of pine straw for longleaf or game mast for cherrybark oak may offer other benefits. Crop yields on the sandy soils on the site were very poor during the 4 years observed, which had a series of droughts and floods. These led to net financial losses in those years for the demonstration site, but state-wide average farm budget returns did show moderate profits. The results support the merits of agroforestry systems in the upper South to diversify income and reduce financial risks.

Title:

Disentangling fragmentation effects on herbivory in understory plants of longleaf pine savanna

Author:

Levey, D. J.

Caughlin, T. T.

Brudvig, L. A.

Damschen, E. I.

Tewksbury, J. J.

Evans, D. M.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Habitat fragmentation affects species and their interactions through intertwined mechanisms that include changes to fragment area, shape, connectivity and distance to edge. Disentangling these pathways is a fundamental challenge of landscape ecology and will help identify ecological processes important for management of rare species or restoration of fragmented habitats. In a landscape experiment that manipulated connectivity, fragment shape, and distance to edge while holding fragment area constant, we examined how fragmentation impacts herbivory and growth of nine plant species in longleaf pine savanna. Probability of herbivory in open habitat was strongly dependent on proximity to forest edge for every species, increasing with distance to edge in six species (primarily grasses and annual forbs) and decreasing in three species (perennial forbs and a shrub). In the two species of perennial forbs, these edge effects were dependent on fragment shape; herbivory strongly decreased with distance to edge in fragments of two shapes, but not in a third shape. For most species, however, probability of herbivory was unrelated to connectivity or fragment shape. Growth was generally determined more strongly by leaf herbivory than by distance to edge, fragment shape, or connectivity. Taken together, these results demonstrate consistently strong edge effects on herbivory, one of the most important biotic factors determining plant growth and demography. Our results contrast with the generally inconsistent results of observational studies, likely because our experimental approach enabled us to tease apart landscape processes that are typically confounded.

Title:

Site preparation for longleaf pine restoration on hydric sites: stand development through 15 years after planting

Author:

Crouch, C. D.

Knapp, B. O.

Cohen, S. A.

Stambaugh, M. C.

Walker, J. L.

Wang, G. G.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine (Pinus palustris Mill.) restoration is an important land management goal throughout the southeastern U.S. On hydric sites within the Atlantic Coastal Plain, restoration may involve site preparation prior to planting to overcome challenges to seedling establishment, such as abundant competition and poor soil drainage. Investment in site preparation assumes that treatments will result in long-term benefits to stand development, yet lasting impacts of site preparation on longleaf pine are not well understood. We sampled longleaf pine plantations in Onslow County, North Carolina through three years and at 15 years after site preparation and planting. The eight study treatments we tested include an untreated control, six combinations of two vegetation control treatments (chopping or herbicide) with three soil manipulation treatments (mounding, bedding, or flatplanting [no treatment]), and a chopping-herbicide-bedding treatment. Our findings indicate that site preparation significantly improved survival and growth of longleaf pine through 15 years. Herbicide resulted in greater growth, higher survival, and earlier grass stage emergence than chopping. Similarly, soil manipulation treatments resulted in improved stand establishment outcomes relative to flat-planting (no treatment). Effects of site preparation treatments on diameter growth were observed early and maintained through the end of the study period, while effects on survival were not observed within the first three years. Differences in stand height among treatments were more strongly driven by growth rates following grass stage emergence than timing of emergence. Our results demonstrate that site preparation improves longleaf pine stand establishment on hydric sites, although the intensity of site preparation treatments recommended for restoration depends on management objectives.

Title:

Successional responses of herbs in the longleaf-slash pine forest after fire

Author:

Lemon, P. C.

Year published:

1949

Publication Type:

Peer-reviewed literature

Title:

Avian taxonomic and functional diversity diversity in early stage of longleaf pine (Pinus palustris) stands restored at agricultural lands: variations in scale dependency

Author:

Lee, M. B.

Gates, B. J.

Cooper, R. J.

Carroll, J. P.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

In agricultural landscapes, the longleaf pine initiative (LLPI) and the Bobwhite Quail Initiative (BQI) aim to restore longleaf pine forests and early successional habitats, respectively. The early stage of longleaf pine stands and grass and forb vegetation produced by a combination of both restoration programs (LLPI-BQI) may form habitat conditions favorable to early successional bird species and other birds, increasing avian diversity. We investigated how the LLPI and BQI programs affected taxonomic and functional diversity of birds and abundance of early successional birds (grassland and scrub/shrub species), and what environmental characteristics were associated with the diversity and abundance of birds. Our study was performed at 41 fields in Georgia, United States, during 2001–2002 by considering environmental characteristics at two spatial scales: local-scale vegetation features and restoration program type (LLPI or LLPI-BQI) and landscape-scale vegetation features and landscape heterogeneity. Functional evenness, species richness, and abundance of grassland and scrub/shrub species did not show a clear association with local- or landscape-scale variables. Shannon-Wiener diversity was slightly influenced by restoration program type (local-scale variable) with higher value at LLPI-BQI stands than at LLPI stands despite no significant differences in local vegetation features between those stands. Functional divergence was strongly positively associated with landscape-scale variables. That is, niche differentiation increased with increasing shrub coverage within a landscape, reducing competition between abundant bird species and others. Our results suggest that although a combination of BQI and LLPI program may have a positive effect on avian taxonomic diversity, it is important to consider shrub vegetation cover within a landscape to improve functional diversity.

Title:

“Effects of dormant and growing season burning on surface fuels and potential fire behavior in northern Florida longleaf pine (Pinus palustris) flatwoods”

Author:

Cronan, J. B.

Wright, C. S.

Petrova, M.

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

Prescribed fire is widely used to manage fuels in high-frequency, low-severity fire regimes including pine flatwoods of the southeastern USA where prescribed burning during the growing season (the frost-free period during the calendar year) has become more common in recent decades. Growing season prescribed fires address ecological management objectives that focus on increasing herb cover and decreasing shrub cover. The shift from shrub to herb dominance due to burning in the growing season corresponds to a change in surface fuels that could affect fire behavior, yet little has been done to assess the potential effects. We examined the effects of season-of-burn on shrub and herbaceous fuel layers and predicted fire behavior at replicate plots on frequently burned mesic pine flatwoods for two season-of-burn treatments (growing and dormant season prescribed fires) in two geographic regions in northern Florida. The Fuel Characteristic Classification System was used to construct a representative fuelbed for each plot at each sampling time to predict fire behavior. Predicted fire behavior was tested for correlation with measured surface fuel properties to determine if there was an effect from differences in fuels characteristics across treatments. In addition, fire temperature was measured in situ as a proxy for fire intensity and tested for treatment effects on the re-growth of live surface fuels. Compared to single dormant season burns, our single growing season burns caused no changes to live understory fuels and had no detectable effect on fire behavior, although predicted rate of spread and flame length were significantly reduced after all prescribed burns. Shrub cover and predicted fire behavior were, however, significantly different between geographic regions, and shrub height was significantly affected by fire temperature. Predicted fire behavior was strongly correlated with measures of the litter and herb strata. Results from this study suggest that land managers should not initially expect large changes in understory fuel properties or potential fire behavior from a shift to burning during the growing season and show that geographic location and fire intensity had significant effects on live fuels and potential fire behavior.

Title:

Genetic integrity of longleaf and shortleaf pine seed orchards and seed banks

Author:

Crane, B.

Hipkins, V.

Josserand, S.

Echt, C.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine (Pinus palustris Mill.) and shortleaf pine (Pinus echinata Mill.) are priority species targeted for increased restoration on the national forests in the Southern Region of the U.S. Department of Agriculture, Forest Service. The genetic integrity of both species is important to ensure adaptation, survival, and resilience of future forests. Longleaf x loblolly pine hybrids (Pinus ×sondereggeri H.H. Chapm. ex Sudw. [palustris × taeda]) and shortleaf x loblolly pine hybrids are known to occur in the general forests, but at a rate of less than 5 percent. Climate change can trigger extreme fluctuations in temperatures, which could influence flower receptivity and result in greater potential for increased inter-species hybridization. This hybridization may compromise the genetic purity of a species and present challenges to successful restoration. It is important to know the genetic identity of the seedlings we are deploying in operational plantings, and the seed being sold to State partners. The Southern Region National Forest System Genetics program chose to DNA fingerprint longleaf and shortleaf pine parents (clones) in the regional seed orchards to assess genetic purity. Final results showed no hybrid fingerprint for the 250 longleaf clones tested and a hybrid fingerprint for 17 of the 619 shortleaf clones tested. The regional seed bank inventory for longleaf and shortleaf pines was also DNA fingerprinted. The seed tested had been collected across multiple years and seed zones. Final results showed a hybrid fingerprint for less than 3 percent of the seed.

Title:

Growth of longleaf and loblolly pine planted on South Carolina sandhill sites

Author:

Cram, M. M.

Outcalt, K. W.

Zarnoch, S. J.

Year published:

2010

Publication Type:

Peer-reviewed literature

Abstract:

Performance of longleaf (Pinus palustris Mill.) and loblolly pine (P. taeda L.) were compared 15–19 years after outplanting on 10 different sites in the sandhills of South Carolina. The study was established from 1988 to 1992 with bareroot seedlings artificially inoculated with Pisolithus tinctorius (Pt) or naturally inoculated with mycorrhizae in the nursery. A containerized longleaf pine treatment with and without Pt inoculation was added to two sites in 1992. Effects of the Pt nursery treatment were mixed, with a decrease in survival of bareroot longleaf pine on two sites and an increase in survival on another site. The containerized longleaf pine treatment substantially increased survival, which led to greater volume compared with bareroot longleaf pine. Loblolly pine yielded more volume than longleaf pine on all sites but one, where survival was negatively affected by fire. Depth of sandy surface horizon affected mean annual height growth of both loblolly and longleaf pine. Height growth per year decreased with an increase in sand depth for both species. Multiple regression analysis of volume growth (ft3/ac per year) for both species indicated a strong relationship to depth of sandy soil and survival. After 15–19 years, loblolly pine has been more productive than longleaf pine, although longleaf pine productivity may be equal to or greater than that of loblolly pine on the soils with the deepest sandy surface layers over longer rotations.

Title:

Forms and amounts of soil nitrogen and phosphorus across a longleaf pine-depressional wetland landscape

Author:

Craft, C. B.

Chiang, C.

Year published:

2002

Publication Type:

Peer-reviewed literature

Abstract:

Forms and amounts of soil N and P were measured across transects from freshwater depressional wetlands into longleaf pine-wiregrass forests of southwestern Georgia to evaluate changes in labile vs. recal-citrant N and P and C:N:P ratios across drainage gradients. Plant-available NO3--N (3.7 μg cm-3) and organic N (2000 μg cm-3) were significantly greater in wetland than upland soils (NO3-N = 0.03 μg cm-3, organic N = 890 μg cm-3) and C:N increased from wetlands (17:1) into uplands (43:1). Forms and amounts of P were not as strongly related to landscape position as N. Labile organic P (Po, 2.6 μg cm-3) was significantly greater in wetland than upland soils (0.88 μg cm-3). Recalcitrant organic compounds accounted for 95 to 97% of the N and 50 to 82% of the P stored in wetland and upland soils. Wetland soils stored a disproportionately large share of N as compared with upland soils even though soil organic matter (C) content was uniform across the landscape. Landscape position (drainage, degree of wetness) is an important determinant of nutrient retention in sandy soils of the southeastern coastal plain. Periodic waterlogging favors sequestration of biological (organic) forms of N and P with proportionally greater storage of N relative to P. Soil waterlogging by promoting accumulation of N more than P favors a shift from N limitation in upland soils towards P limitation in wetland soils of the southeastern coastal plain.

Title:

Understory restoration in longleaf pine sandhills

Author:

Cox, A. C.

Gordon, D. R.

Slapcinsky, J. L.

Seamon, G. S.

Year published:

2004

Publication Type:

Peer-reviewed literature

Abstract:

Loss of over 98% of the original extent of longleaf pine (Pinus palustris Mill.) systems has resulted in the need for development of understory restoration techniques. In natural longleaf pine systems recruitment of understory dominant species like wiregrass (Aristida stricta Michx.) likely occurs following opening of the canopy by fire or other localized disturbances. We investigated site preparation and sowing methods for reestablishing dominant understory species in heavily disturbed xeric sandhills. Wiregrass establishment was significantly higher in burned and irrigated plots than in plots that were only burned or were burned and had soil disturbance. However, without irrigation, burned and disturbed sites showed greater establishment than did either treatment alone. Overall, species richness and cover showed the same patterns when irrigation was present, but were higher in disturbed soils without fire when not irrigated. We recommend sowing native seed mix with a hayblower onto areas with light soil disturbance if irrigation is not possible. Subsequent rolling of seed into soil will increase seedling establishment. Mechanical re-establishment of native groundcover in xeric longleaf pine systems is clearly possible.

Title:

Two centuries of forest compositional and structural changes in the Alabama Fall Line hills

Author:

Cox, L. E.

Hart, J. L.

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

Documenting changes in forest composition and structure through time and in response to disturbances strengthens our understanding of the processes that have created contemporary forest ecosystems. Results from these studies also provide the historical r.lnge ofvariation in forest characteristics, which is essential for establishing place-based targets for forest management. Using historical archives and current forest inventory data from the past two centuries, we quantified forest composition and structure following fundamental shifts in land use for a forest in the Fall Line Hills of Alabama (pre-European settlement (1820 and 1842), pre-industrial logging (905), U.S. Forest Service acquisition (1943), and contemporary conditions (present». To quantifY conditions prior to European settlement, we analyzed General Land Office surveys of 1820 and 1842. We used Reed (1905) and Harper (1943) to document conditions during the early to mid-20th century. To quantify current forest conditions, we sampled 80 0.04 ha fixed area plots throughout the study area. Forest structure shifted from relatively large trees at low densities, with few small stems prior to European settlement to a relatively high density of small stems, with few large trees post-industrial logging. Although relative contributions of species varied over the past two centuries, forest composition remained relatively stable. Despite changes in land use, Pinus palustris remained the most common species in the forest.

Title:

Forest landscapes: their effect on the interaction of the southern pine beetle and red-cockaded woodpecker

Author:

Coulson, R. N.

Guzman, M. D.

Skordinski, K.

Fitzgerald, J. W.

Conner, R. N.

Rudolph, D. C.

Oliveria, F. L.

Wunneburger, D. F.

Pulley, P. E.

Year published:

1999

Publication Type:

Peer-reviewed literature

Abstract:

The nature of the interaction of the southern pine beetle and red-cockaded woodpecker was investidgated using spatially explicit information on the structure of a forest landscape mosiac and knowledge of the behavior of the two organisms. This interaction is the basis for defind functional heterogeneity - how an organism perceives and responds to the elements forming the landscape. Implications for forest landscape managment are discussed. The approach used illustrates how information on landscape configuration can be used with knowledge of animal behavior to investigate species interaction in forests.

Title:

Heartwood, sapwood, and fungal decay associated with red-cockaded woodpecker cavity trees

Author:

Conner, R. N.

Rudoplph, D. C.

Saenz, D.

Schaefer, R. R.

Year published:

1994

Publication Type:

Peer-reviewed literature

Abstract:

Provision of suitable sites for red-cockaded woodpecker (Picoides borealis) cavity excavation essential for successful management of the woodpecker. To evaluate internal characteristics of pines the woodpecker, we increment-cored longleaf pines (Pinus palustris) to determine heartwood diameter, sapwood thickness, and presence of fungal heartwood decay at 1.3, 6.0, 9.0, and 12.0 m aboveground red-cockaded woodpecker cavity trees and 53 similar control pines in eastern Texas. Red-cockaded pecker cavity trees had thinner sapwood and greater heartwood diameter at all heights than did control (P < 0.05). Cavity and control trees were similar in height (P = 0.38) and bole length (P = 0.51), but trees were larger (51.1 vs. 48.4 cm diam at breast height [dbh], P = 0.046), older (124.5 vs. 98.5 0.001), and were growing with less vigor (P < 0.001) than were control pines. Red-cockaded woodpeckers require approximately 15-cm diameter of heartwood in which to excavate cavities. Longleaf pines years old had sufficient heartwood to house cavities at 6 and 9 m aboveground. Only pines exceeding 110 years in age had sufficient heartwood present for cavity excavation at 12 m. However, unlike studies, heartwood decay was not detected until trees were >100 years and did not occur with any regularity until pines were >120 years.

Title:

Fungi and red-cockaded woodpecker cavity trees

Author:

Conner, R. N.

Locke, B. A.

Year published:

1982

Publication Type:

Peer-reviewed literature

Title:

Habitat associated with daytime refugia of fox squirrels in a longleaf pine forest

Author:

Conner, L. M.

Godbois, I. A.

Year published:

2003

Publication Type:

Peer-reviewed literature

Abstract:

Fox squirrel (Sciurus niger) populations are declining in many areas of the eastern United States, and habitat loss may be partly responsible for these declines. We measured habitat variables at fox squirrel refuge sites and random sites and used an information theoretic approach to determine the influence of these variables on probability of a site being used for refuge. There was compelling evidence to support tree and stand level habitat variables as important predictors of refuge sites, but little evidence in support of understory variables. Fox squirrels were more likely to use hardwoods than pines (Pinus spp.) for refuge. Tree size (height and diameter) was positively associated with probability of use as was tree density around the refuge site. Percent debris groundcover, the only understory variable of importance, was positively related to probability of use as a refuge site, but the parameter estimate did not convincingly differ from zero. We conclude that large hardwoods within an open-canopy pine matrix are important as fox squirrel refuge sites.

Title:

Countering the broadleaf invasion: financial and carbon consequences of removing hardwoods during longleaf pine savanna restoration

Author:

Condon, B.

Putz, F. E.

Year published:

2007

Publication Type:

Peer-reviewed literature

Abstract:

The once widespread Longleaf pine (Pinus palustris)–dominated ecosystems of the southeastern coastal plain of the United States have been greatly reduced in extent, and many of the remaining stands are being degraded by hardwood invasion due to fire suppression. The first step toward pine savanna restoration is often hardwood removal, a costly process due to their large volumes and low market values. Despite these problems, by marketing a wide range of hard- and softwood products, the costs of 13 restoration projects in northern Florida were substantially reduced. Ten different products were sold to 19 different buyers. Fuel chips represented 71–100% of all biomass removed (8.2–81.1 Mg/ha). Although landowners were charged modest amounts for removing biomass harvested as fuel chips, other marketed products yielded revenues. Overall, four projects earned net profits of $29–$383/ha, and four projects generated sufficient revenue to pay 17–99% of the cost of hardwood removal as fuel chips. A carbon accounting of a second set of projects demonstrated that carbon harvested as fuel chips far exceeded that consumed in harvest and transport, yielding net carbon offsets of 451–1,320 Mg C/project (3.3–13.9 Mg C/ha). Using fuel consumption results of this second set of projects, carbon offsets for the 13 restoration projects were estimated as 89–1,524 Mg (3.8–37.9 Mg C/ha). Restorationists should monitor traditional forest product markets as well as developing carbon markets for price fluctuations that could provide significant revenues to restoration projects.

Title:

Seed bank viability in disturbed longleaf pine sites

Author:

Cohen, S.

Braham, R.

Sanchez, F.

Year published:

2004

Publication Type:

Peer-reviewed literature

Abstract:

Some of the most species-rich areas and highest concentrations of threatened and endangered species in the southeastern United States are found in wet savanna and flatwood longleaf pine (Pinus palustris Mill.) communities. Where intensive forestry practices have eliminated much of the natural understory of the longleaf ecosystem, the potential for reestablishment through a seed bank may present a valuable restoration opportnnity. Longleaf pine sites converted to loblolly pine plantations and non-disturbed longleaf sites on the Coastal Plain of North Carolina were examined for seed bank presence and diversity. Conducting vegetation surveys and examining the seed bank using the seedling emergence technique allowed for verification of the seed bank presence, as well as evaluation of the quality of the seed bank on disturbed longleaf pine sites. Forty-three species and over 1,000 individuals germinated, and the seed banks of both the disturbed and non-disturbed stand types contained species not noted in the vegetation survey. Although many of these species were considered weedy and typical of disturbance, numerous taxawere indicative of stable longleafpine communities. This study confirms both the presence and quality of seed banks in highly disturbed former longleafpine sites, suggesting that the seed bank may be an important tool in restoration efforts.

Title:

Frequent prescribed burning as a long-term practice in longleaf pine forests does not affect detrital chemical composition

Author:

Coates, T. A.

Chow, A. T.

Hagan, D. L.

Wang, G. G.

Bridges, W. C.

Dozier, J. H.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

The O horizon, or detrital layer, of forest soils is linked to long-term forest productivity and health. Fuel reduction techniques, such as prescribed fire, can alter the thickness and composition of this essential ecosystem component. Developing an understanding of the changes in the chemical composition of forest detritus due to prescribed fire is essential for forest managers and stakeholders seeking sustainable, resilient, and productive ecosystems. In this study, we evaluated fuel quantity, fuel structure, and detrital chemical composition in longleaf pine (Pinus palustris Miller) forests that have been frequently burned for the last 40 yr at the Tom Yawkey Wildlife Center in Georgetown, SC. Our results suggest that frequent prescribed fire reduces forest fuel quantity (p < 0.01) and vertical structure (p = 0.01). Using pyrolysis–gas chromatography/mass spectrometry as a molecular technique to analyze detrital chemical composition, including aromatic compounds and polycyclic aromatic hydrocarbons, we found that the chemical composition of forest detritus was nearlyuniform for both unburned and burned detritus. Our burning activities varied in the short term, consisting of annual dormant, annual growing, and biennial dormant season burns. Seasonal distinctions were present for fuel quantity and vertical fuel structure, but these differences were not noted for the benzene/phenol ratio. These results are significant as more managers consider burning existing longleaf stands while determining effective management practices for longleaf stands yet to be established. Managers of such stands can be confident that frequent, low-intensity, low-severity prescribed burns in longleaf pine forests do little to affect the long-term chemical composition of forest detritus.

Title:

Transient changes in transpiration, and stem and soil CO2 efflux in longleaf pine (Pinus palustris Mill.) following fire-induced leaf area reduction

Author:

Clinton, B. E.

Maier, C. A.

Ford, C. R.

Mitchell, R. J.

Year published:

2011

Publication Type:

Peer-reviewed literature

Abstract:

In 20-year-old longleaf pine, we examined short-term effects of reduced live leaf area (A L) via canopy scorching on sap flow (Q; kg H2O h−1), transpiration per unit leaf area (E L; mm day−1), stem CO2 efflux (R stem; μmol m−2 s−1) and soil CO2 efflux (R soil; μmol m−2 s−1) over a 2-week period during early summer. R stem and Q were measured at two positions (1.3-m or BH, and base of live crown—BLC), and R soil was measured using 15 open-system chambers on each plot. E L before and after treatment was estimated using Q measured at BLC with estimates of A L before and after scorching. We expected Q to decrease in scorched trees compared with controls resulting from reduced A L. We expected R stem at BLC and BH and R soil to decrease following scorching due to reduced leaf area, which would decrease carbon supply to the stem and roots. Scorching reduced A L by 77%. Prior to scorching, Q at BH was similar between scorch and control trees. Following scorching, Q was not different between control and scorch trees; however, E L increased immediately following scorching by 3.5-fold compared to control trees. Changes in E L in scorched trees corresponded well with changes in VPD (D), whereas control trees appeared more decoupled over the 5-day period following treatment. By the end of the study, R stem decreased to 15–25% in scorched trees at both stem positions compared to control trees. Last, we found that scorching resulted in a delayed and temporary increase in R soil rather than a decrease. No change in Q and increased E L following scorching indicates a substantial adjustment in stomatal conductance in scorched trees. Divergence in R stem between scorch and control trees suggests a gradual decline in stem carbohydrates following scorching. The absence of a strong R soil response is likely due to non-limiting supplies of root starch during early summer.

Title:

Bioturbation by mammals and fire interact to alter ecosystem-level nutirent dynamics in longleaf pine forests

Author:

Clark, K. L.

Branch, L. C.

Farrington, J.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Activities of ecosystem engineers can interact with other disturbances to modulate rates of key processes such as productivity and nutrient cycling. Bioturbation, movement of soil by organisms, is a widespread form of ecosystem engineering in terrestrial ecosystems. We propose that bioturbation by southeastern pocket gophers (Geomys pinetis), an abundant but declining ecosystem engineer in longleaf pine (Pinus palustris Mill.) forests, accelerates nutrient dynamics of the forest floor by burying litter and then reduces litter consumption and nitrogen (N) volatilization losses in the presence of fire. We evaluated our hypothesis by measuring how litter burial alters decomposition and N and phosphorus (P) turnover of longleaf pine and turkey oak (Quercus laevis Walt.) litter over four years, and then simulated interactive ecosystem-level effects of litter burial and low-intensity fires on N and P dynamics of the litter layer. In the field, mass loss was over two times greater and N and P were released much more rapidly from litter buried beneath mounds than on the surface of the forest floor. At a measured rate of mound formation covering 2.3 ± 0.6% of the forest floor per year, litter mass and N and P content of the forest floor simulated over an eight-year period were approximately 11% less than amounts in areas without pocket gopher mounds. In contrast to unburied litter, litter beneath mounds is protected from consumption during fires, and as fire interval increased, consumption rates decreased because mounds cover more years of accumulated litter. Our research indicates that bioturbation and burial of litter by pocket gophers accelerates turnover of N and P on the forest floor, and in the presence of fire, conserves N in this ecosystem where productivity is known to be nutrient limited.

Title:

Evaluating climate planning for longleaf pine ecosystems in the southeast United States

Author:

Clark, K. E.

Chin, E.

Peterson, M. N.

Lackstrom, K.

Dow, K.

Foster, M.

Cubbage, F.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine (LLP, Pinus palustris) has been reduced to 3–5% of its original range, but may be particularly resilient to conditions associated with climate change including drought, severe storms, and increased prevalence of pests. Despite the critical role of LLP in building climate resilient ecosystems, little is known about how landscape managers in the region have considered climate change in planning efforts. We gathered 83 publicly accessible natural resource management plans from the southeastern United States that included management of LLP ecosystems between 1999 and 2016. We used document analysis to identify how plans addressed climate change threats on LLP, considered climate change in identification of LLP ecosystems, and linked climate change to planned conservation actions for LLP ecosystems. Newer plans and plans from state agencies tended to include greater consideration of climate change than older plans, federal plans, and those developed by nongovernmental organizations (NGO) or Joint Venture partnerships. Additionally, state wildlife action plans and forest action plans tended to score higher than other types of plans, such as plans from the Department of Defense, U.S. Forest Service, and NGOs. Considering climate vulnerability in planning efforts of LLP ecosystems is an opportunity because LLP represents a hopeful context for conserving vulnerable wildlife species as ecosystems adapt and evolve. Limited consideration of climate change as a criterion for identifying or evaluating LLP ecosystems by agencies may result from climate discourse focusing on ecosystems most vulnerable, versus resilient to, climate change. A stronger focus on climate change in longleaf pine community restoration may help forest managers promote sustainable forests and more hopeful conservation planning in the Southeast United States.

Title:

Changes in tree canopy, understory vegetation, and fuel composition after 10 years of restoration management in an old-growth mountain longleaf pine forest

Author:

Cipollini, M. L.

Felch, P.

Dingley, N. R.

Maddox, C.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

The Berry College Longleaf Pine Management Area (BCLPMA) harbors one of the few old-growth mountain longleaf pine (Pinus palustris) forests. Like many remnant longleaf pine forests, Berry College’s stands have been fire-suppressed for decades. Since 2003, ~160 ha of the BCLPMA has been managed using prescribed burns and herbicide injection of hardwoods with the goal of achieving an open, pine-dominated canopy, low duff, litter, and downed woody fuels, increased groundcover vegetation, and improved longleaf pine recruitment. Canopy tree structure was quantified using the point-quarter method in eight managed and five unmanaged stands in 2004 and 2014. Understory vegetation and downed woody fuels were estimated in a subset of these stands in 2003/2004 and 2015 using a plane-intercept method. Data from mountain longleaf pine stands in Alabama were included as external frequently burned and fire-suppressed references. Overall canopy and understory structure of managed stands has moved over time in the direction of frequently burned external reference stands. Longleaf pine basal area has been maintained and importance values have increased with management despite the loss of some canopy trees associated with duff smoldering after burning. Duff and litter levels have decreased substantially in managed stands, while understory plant cover (herbs, grasses, shrubs, vines, and small trees) has increased. Downed woody fuels, which have varied as a result of fire events, have generally dropped in managed stands, whereas longleaf pine recruitment has increased. Results show progress being made in restoring the vegetative structure to desired conditions and may inform analogous restoration projects throughout the mountain longleaf pine ecosystem.

Title:

Macroarthropod response to time-since-fire in the longleaf pine ecosystem

Author:

Chitwood, M. C.

Lashley, M. A.

Sherrill, B. L.

Sorenson, C.

Deperno, C. S.

Moorman, C. E.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Fire is an important disturbance worldwide, and literature supports the use of prescribed fire to restore and maintain fire-dependent ecosystems. However, fire could alter the abundance and persistence of some arthropods, in turn influencing vertebrate taxa that depend on those arthropods as a food source. We used replicated prescribed fire treatments to evaluate macroarthropod response to time-since-fire in the fire-maintained longleaf pine (Pinus palustris) ecosystem. We sampled macroarthropod assemblages using vinyl gutter pitfall traps for 5 consecutive days in each month of the study (May-August 2014) in each replicate burn block. We identified macroarthropods to Order and dried and weighed the samples to determine biomass (g) of all taxa detected. We focused our analyses on 4 macroarthropod taxa important as food for wild turkey (Meleagris gallopavo): Araneae, Coleoptera, Hymenoptera, and Orthoptera. We used standard least squares regression to evaluate the effect of time-since-fire on total biomass of the 4 Orders (and we also evaluated those Orders independently). The analysis indicated that time-sincefire had no effect (p = 0.2616) on combined biomass of these 4 taxa. Analyzing the 4 Orders separately, biomass of Araneae (p = 0.0057) and Orthoptera (p = 0.0004) showed significant effects of time-sincefire, while Coleoptera (p = 0.9465) and Hymenoptera (p = 0.1175) did not. Parameter estimates (Araneae = 0.0084; SE = 0.0029; Orthoptera = 0.0137; SE = 0.0036) indicated that greater time-since-fire resulted in greater biomass for those 2 Orders. Overall, time-since-fire did not appear to have substantial effects on macroarthropod biomass. However, responses by Araneae and Orthoptera provided evidence that longer time-since-fire may result in greatest levels of biomass for some taxa. Our results indicate the use of frequent prescribed fire to restore and maintain longleaf forests is unlikely to pose risks to overall macroarthropod biomass, particularly if heterogeneity in fire frequency and spatial extent occurs on the landscape.

Title:

Coyote diets in a longleaf pine ecosystem

Author:

Cherry, M. J.

Turner, K. L.

Howze, M. B.

Cohen, B. S.

Conner, L. M.

Warren, R. J.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

The ecological implications of coyote Canis latrans colonization of the eastern USA have drawn considerable interest from land managers and the general public. The ability to predict how these ecosystems, which have lacked larger predators for decades, would respond to the invasion of this highly adaptable species needs an understanding of coyote foraging behavior given local resource availability. Therefore, we examined the diet of coyotes in a longleaf pine Pinus palustrus ecosystem from 2007–2012. We examined 673 coyote scats collected on the Joseph W. Jones Ecological Research Center in southwestern Georgia. We observed considerable seasonality in coyote use of rodents, white-tailed deer Odocoileus virginianus, rabbits and vegetation. Coyotes exploited anthropogenic food sources, particularly waste peanuts Arachis hypogaea, during the fall and winter when native soft mast was not available. Adult white-tailed deer were consumed during every month and was not limited to the pulse of carrion availability from hunter-harvested animals, suggesting the use of adult white-tailed deer may not be restricted to scavenging in this system. We found mesomammals, including armadillos Dasypus novemcinctus, raccoons Procyon lotor, Virginia opossums Didelphis viginiana, bobcats Lynx rufus, grey foxes Urocyon cineroargenteus and striped skunks Mephitis mephitis in approximately 18% of coyote scats from January–August. On our site, and some adjacent properties, the use of predator trapping focused primarily on Virginia opossum, raccoon, coyote, bobcat and gray fox, to increase northern bobwhite Colinus virginianus production may have resulted in increased use of mesomammals through scavenging. We offer evidence that coyote colonization may alter food web dynamics in longleaf pine ecosystems through depredation of white-tailed deer and by influencing the mesomammal guild through direct predation and competition for rodents, rabbits, carrion and soft mast.

Title:

Effects of predation risk and group dynamics on white-tailed deer foraging behavior in a longleaf pine savanna

Author:

Cherry, M. J.

Conner, L. M.

Warren, R. J.

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

Costs associated with antipredator behaviors can have profound effects on prey populations. We investigated the effects of predation risk on white-tailed deer foraging behavior by manipulating predator distributions through exclusion while controlling for effects of habitat type. In 2003, we constructed predator exclosures on 4 of 8 approximately 40-ha study plots in southwestern Georgia, USA. We examined the seasonal and sex-specific effects of predator exclusion, and group size and composition on the behavioral state (i.e., feeding or vigilant) of foraging white-tailed deer at baited camera traps during 2011–2012. Predator exclusion resulted in a 5% increase in the time females spent feeding during the summer, concurrent with fawning; and 13.4% increase in the time males spent feeding during winter, while in postrut condition. Males were more vigilant than females and demonstrated a stronger response to predator exclusion. Males showed no response to group size or composition, whereas females and juveniles decreased foraging when males were present during the summer. Our results suggest that white-tailed deer alter vigilance levels in response to predator distributions independent of habitat cues. We propose that expanding coyote populations in the southeastern USA influence white-tailed deer numerically through predation of juveniles, and behaviorally by inducing antipredator responses that likely carry foraging costs. This emerging predator–prey dynamic may have strong nonconsumptive effects on naive white-tailed deer populations that experienced little nonanthropogenic predation risk for decades.

Title:

Characterizing the dynamics of cone production for longleaf pine forests in the southeastern United States

Author:

Chen, X.

Brockway, D. G.

Guo, Q.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine (Pinus palustris Mill.) forests are historically and ecologically important and also endangered ecosystems in the southeastern United States. In addition to extensive exploitation and land use conversion, one characteristic which contributed to their dramatic decline and presents a continuing challenge to their future recovery is the sporadic timing of their seed production. In this study, about 60 years of cone production data for longleaf pine forests at four different sites were quantitatively characterized from different perspectives. Results indicated that longleaf pine was different from masting species and there was no general trend of increasing coefficient of variation (CV) in cone production through time. On a decade scale, there was a significantly positive correlation between the CV of cone production and CV of average annual air temperature, but the CV of annual precipitation was negatively correlated with the CV of cone production at the Escambia (AL) and Blackwater (FL) sites. Phase coupling of cone production with a strength of approximately 0.4 existed only between the Escambia and Blackwater sites and no significant phase coupling was found between other sites. The implications of these results for forest management are discussed from a perspective of spatial and temporal complexity.

Title:

Analyzing the complexity of cone production in longleaf pine by multiscale entropy

Author:

Chen, X.

Guo, Q.

Brockway, D. G.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

The longleaf pine (Pinus palustris Mill.) forests are important ecosystems in the southeastern USA because of their ecological and economic value. Since European settlement, longleaf pine ecosystems have dramatically declined in extent, to the degree that they are now listed as endangered ecosystems. Its sporadic seed production, which limits the frequency of natural regeneration, is identified as a significant factor in this decline. Previous studies did not characterize the complexity in cone production. Here a method of multiscale entropy is used to analyze long-term data for cone production in longleaf pine forests at six sites across its native range. Our results indicate that there exists a regime shift for cone production at each site. The corresponding time scales of the regime shift are generally 1–9, 10–12, 13–16, and 17–24 yr. Overall patterns for the complexity of cone production with the change of time scale are similar among sites, with exception of the Red Hills (FL). There are high correlations between entropy of cone production and entropy of annual mean air temperature and annual total precipitation at all sites. These results provide new insight into the complexity of cone production of longleaf pine forests with significant management implications.

Title:

Height-diameter relationships in longleaf pine and four swamp tree species

Author:

Chen, X.

Brockway, D. G.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

The scaling relationship between height and diameter is important for understanding the dynamic patterns of tree growth and estimating the accrual of tree biomass. Metabolic ecology predicts that tree growth follows a universal scaling invariant relative to the height-diameter relationship (i.e., no variation based on taxonomy or resource availability). Comparing field data for different tree species across a range of site conditions should be an informative test of that prediction. Our results indicate that the scaling exponents of height and diameter for longleaf pine (Pinus palustris Mill.) vary at the four locations across its natural range. As for swamp trees, the scaling exponents for red maple (Acer rubrum L.) and river birch (Betula nigra L.) were consistent with that predicted by metabolic ecology; however, those for water tupelo (Nyssa aquatica L.) and bald cypress (Taxodium distichum (L.) Rich) were not. Our study confirms that high plasticity and variation in allometric scaling of the tree height and diameter relationship may very well be the rule, rather than the exception.

Title:

Functional relationships reveal keystone effects of gopher tortoise on vertebrate diversity in a longleaf pine sanavva

Author:

Catano, C. P.

Stout, I. J.

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

Keystone species are important drivers of diversity patterns in many ecosystems. Their effects on ecological processes are fundamental to understanding community dynamics, making them attractive conservation targets for ecosystem management. However, many studies assume keystone effects are constant. By developing functional relationships of species’ effects and assessing how they vary with context, we can design more efficient conservation strategies to maintain keystone impacts. The threatened gopher tortoise (Gopherus polyphemus) is presumed to be a keystone species promoting biodiversity in endangered longleaf pine ecosystems of the Southeastern Coastal Plain, USA. Although many commensals use tortoise burrows, their putative keystone influence on emergent diversity patterns lacks critical evaluation. We quantified the functional relationship between tortoise burrow density and non-volant vertebrate diversity in a longleaf pine savanna, located in central Florida. Tortoise burrow density had a positive effect on vertebrate diversity and evenness but did not affect species richness. This relationship was robust across fire disturbance regimes and was the primary factor explaining diversity at the local scale. Our results demonstrate keystone effects of the gopher tortoise through an ecosystem engineering mechanism. Continued gopher tortoise population declines will have large, negative impacts on vertebrate diversity in this biodiversity hotspot. Therefore, maintaining gopher tortoise populations is critical to effectively conserve dependent species and the function of endangered longleaf pine ecosystems. We show that developing a functional understanding of keystone relationships (not a binomial categorization) can lead to important insights into community processes.

Title:

Tree species effects on understory forage productivity and microclimate in a silvopasture of the southeastern USA

Author:

Castillo, M. S.

Tiezzi, F.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Ecosystem services provided by silvopastoral systems are mediated by specific management practices, environmental conditions, and overall design of the system. We hypothesized that selection of tree species affects understory forage nutritive value and productivity, light/shade environment, and microclimate. The silvopastoral system was located at the Center for Environmental Farming Systems in Goldsboro, North Carolina, USA. Three overstory tree-species were Pinus palustris (PP; longleaf pine), Pinus taeda (PT; lobloblly pine), and Quercus pagoda (QP; cherrybark oak). The understory forage component consisted of a four-way mixture of native warmseason grasses [big bluestem (Andropogon gerardii, ‘Eastern’, KY origin), eastern gamagrass (Tripsacum dactyloides, MO origin), indiangrass (Sorghastrum nutans, ‘NC ecotype’), and switchgrass (Panicum virgatum, ‘Alamo’)]. The experimental design was an RCBD with 3 replicates. There was no effect of seedbed preparation (till versus no-till) on forage establishment. Understory dry matter yield, crude protein and total digestible nutrient concentrations of the harvested forage were not affected by tree species, with the exception at the 3.5 south sampling point. Overstory effects on microclimate variables were not different among tree-species, but were more noticeable during the daytime of the summer months, and were at the most 1-degree point for temperature and temperature-humidity index and 3 points for relative humidity. The silvopasture design in our study provided year-round shade by the tree-component, with varying levels of shade (ranging from 90 to 6% of incident photosynthetic active radiation) due to geographic location, tree species, and season. Our results describe and highlight the potential of trees in a silvopasture design in the southeastern USA to mitigate changes in temperature, humidity, the temperature-humidity index, and forage productivity and as a function of tree species and at different distance from the trees.

Title:

Genetic variation in water-use efficiency (WUE) and growth in mature longleaf pine

Author:

Castillo, A. C.

Goldfarb, B.

Johnsen, K. H.

Roberds, J. H.

Nelson, C. D.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

The genetic and physiological quality of seedlings is a critical component for longleaf pine (Pinus palustris Mill.) restoration, because planting genetic material that is adapted to environmental stress is required for long-term restoration success. Planting trees that exhibit high water-use efficiency (WUE) is a practice that could maximize this species’ survival and growth in a changing climate. Our study evaluates genetic variation in WUE and growth, as well as WUE-growth relationships, a key step to determine potential for breeding and planting trees with high WUE. We measured carbon isotope discrimination (D)—a proxy for WUE—in 106 longleaf pine increment cores extracted from trees belonging to nine full-sib families. Tree diameter and total tree height were also measured at ages 7, 17, 30 and 40 years. Each increment core was divided into segments corresponding to ages 7–17, 18–30 and 31–40, representing early, intermediate and mature growth of the trees. We identified significant genetic variation in DBH and WUE among families that merit further exploration for identifying trees that can potentially withstand drought stress. Mean family growth rates were not associated with mean family values for carbon isotope discrimination. Family variation in both diameter growth and WUE but no relationship between family values for these traits, suggests it is possible to improve longleaf pines in both diameter growth and WUE through appropriate breeding.

Title:

The conservation reserve program and wildlife habitat in the southeastern United States

Author:

Carmichael, D. B.

Year published:

1997

Publication Type:

Peer-reviewed literature

Title:

Effects of prescribed fire and other plant community restoratino treatments on tree mortality, bark beetles, and other saproxylic Coleoptera of longleaf pine, Pinus palustris Mil., of the Coastal Plain of Alabaman

Author:

Campbell, J. W.

Hanula, J. L.

Outcalt, K. W.

Year published:

2008

Publication Type:

Peer-reviewed literature

Abstract:

Treatments to restore understory plant communities of mature (50-80-year old) longleaf pine (Pinus palustris Mill.) and reduce risks of wildfire were applied to 10 ha plots that had a substantial shrub layer due to lack of fire. Plots were located in the Coastal Plain of Alabama and treatments consisted of: (1) untreated control, (2) growing season prescribed bum, (3) thin only. (4) thin plus growing season bum, and (5) herbicide plus growing season bum. Thin plus bum plots had significantly higher tree mortality compared to bum only and control plots and, overall, fire was the primary cause of tree death. Most tree mortality occurred within 1-year of treatment. From 2002 to 2004, we captured 75,598 Coleoptera in multiple funnel traps comprising 17 families and 130 species. Abundance of all Coleoptera combined was not different among treatments. Species richness was significantly higher on thin plus bum plots compared to thin only and control plots. Scolytinae (Coleoptera: Curculionidae) were more abundant on thin plus burn plots compared to control plots in fall 2002 but in fall 2003 they were more abundant on thin plus bum, thin only, and herbicide plus bum compared to controls. Among Scolytinae, Dendroctonus terebrans (Olivier), Xyleborinus saxeseni (Ratzeburg), Xyleborus sp. 3, and Hylastes tenuis (Eichhoff), showed varying responses to the treatments. Other Curculionidae were significantly more abundant on thin only and herbicide plus bum plots compared to all other treatments in spring 2003 and in spring 2004 they were more abundant on herbicide plus bum plots compared to thin plus bum treatments. Among Cerambycidae, Xylotrechus sagittatus (Germar) was higher in abundance in fall 2003 on thin plus bum plots compared to all other treatments except herbicide plus burn plots. Within the predator complex, Trogositidae were higher on thin plus bum plots compared to all other treatments except thin only plots in spring 2003, and Cleridae abundance was higher in spring 2004 on bum only plots compared to all other treatments. Linear regression analyses of dead trees per plot versus various Colwptera showed captures of Buprestidae, Cerambycidae, Trogositidae, Acanthocinus nodosus (Fabricius), Ternnochila virescens (Fabricius), and X. saxeseni increased with increasing number of dead trees. Our results show that the restoration treatments tested did not cause increased bark beetle-related tree mortality and they did not negatively affect populations of early successional saproxylic beetle fauna.

Title:

Determination of grazing values of native vegetation on southern pine forest ranges

Author:

Campbell, R. S.

Year published:

1946

Publication Type:

Peer-reviewed literature

Title:

Intra-annual variation in soil C, N and nutrients pools after prescribed fire in a Mississippi longleaf pine (Pinus palustris Mill.) plantation

Author:

Butnor, J. R.

Johnsen, K. H.

Maier, C. A.

Nelson, C. D.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Prescribed fire is an essential tool that is widely used for longleaf pine (Pinus palustris Mill.) stand management; periodic burning serves to reduce competition from woody shrubs and fire-intolerant trees and enhance herbaceous diversity. Low-intensity, prescribed burning is thought to have minimal long-term impact on soil chemistry in southern pine forests, although few studies report the intra-annual variation in soil chemistry after burning. We monitored changes in C, N, oxidation resistant C (CR), pH and elemental nutrients in the forest floor and soil (0–5, 5–10 cm depths) before and after burning (1, 3, 6, 12 months) in a mature longleaf pine plantation at the Harrison Experimental Forest, near Saucier, Mississippi. Prescribed fire consumed much of the forest floor (11.3 Mg ha?1; ?69%), increased soil pH and caused a pulse of C, N and elemental nutrients to flow to the near surface soils. In the initial one to three months post-burn coinciding with the start of the growing season, retention of nutrients by soil peaked. Most of the N (93%), Ca (88%), K (96%) and Mg (101%), roughly half of the P (48%) and Mn (52%) and 25% of the C lost from the forest floor were detected in the soil and apparently not lost to volatilization. By month 12, soil C and N pools were not different at depths of 0–5 cm but declined significantly below pre-burn levels at depths of 5–10 cm, C ?36% (p < 0.0001), N ?26% (p = 0.003), contrary to other examples in southern pine ecosystems. In the upper 5 cm of soil, only Cu (?49%) remained significantly lower than pre-burn contents by month 12, at depths of 5–10 cm, Cu (?76%), Fe (?22%), K (?51%), Mg (?57%), Mn (?82%) and P (?52%) remain lower at month 12 than pre-burn contents. Burning did not increase soil CR content, conversely significant declines in CR occurred. It appears that recovery of soil C and N pools post-burn will require more time on this site than other southern pine forests.

Title:

Pollen limitation and self-compatibility in three pine savanna herbs

Author:

Burt, M. A.

Brudvig, L. A.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

There is substantial interest in the restoration of the Pinus palustris (Longleaf Pine) savannas in the southeastern US Coastal Plain, one of the most endangered ecosystems in the world and also home to a diverse plant assemblage. Better understanding of the pollination ecology of these plants is necessary for their successful conservation and restoration. In this study, we assessed the rates of self-compatibility and pollen limitation in Carphephorus bellidifolius (Sandywoods Chaffhead), Liatris squarrulosa (Appalachian Blazing Star), and Aristida beyrichiana (Wiregrass)—3 perennial understory herbaceous species of conservation interest. We measured self-compatibility with a pollination-exclusion–bag experiment and pollen limitation with a pollen-supplementation experiment within South Carolina populations. We found no evidence of pollen limitation in any of these 3 species. This result is surprising given the high incidence of pollen limitation typically found in other study systems. Our pollination-exclusion bag experiment showed that Sandywoods Chaffhead likely requires out-cross pollen for successful pollination, whereas both Appalachian Blazing Star and Wiregrass appear to exhibit at least low levels of self-compatibility. Taken together, our results may indicate that the active management of the Longleaf Pine ecosystem with prescribed fire and overstory tree removal has supported sufficient pollination in these plant populations.

Title:

Landscape connectivity promotes plant biodiversity spillover into non-target habitats

Author:

Brudvig, L. A.

Damschen, E. I.

Tewksbury, J. J.

Haddad, N. M.

Levey, D. J.

Year published:

2009

Publication Type:

Peer-reviewed literature

Abstract:

Conservation efforts typically focus on maximizing biodiversity in protected areas. The space available for reserves is limited, however, and conservation efforts must increasingly consider how management of protected areas can promote biodiversity beyond reserve borders. Habitat corridors are considered an important feature of reserves because they facilitate movement of organisms between patches, thereby increasing species richness in those patches. Here we demonstrate that by increasing species richness inside target patches, corridors additionally benefit biodiversity in surrounding non-target habitat, a biodiversity ‘‘spillover’’ effect. Working in the world’s largest corridor experiment, we show that increased richness extends for approximately 30% of the width of the 1-ha connected patches, resulting in 10–18% more vascular plant species around patches of target habitat connected by corridors than around unconnected but otherwise equivalent patches of habitat. Furthermore, corridor-enhanced spillover into non-target habitat can be predicted by a simple plant life-history trait: seed dispersal mode. Species richness of animal-dispersed plants in non-target habitat increased in response to connectivity provided by corridors, whereas species richness of wind-dispersed plants was unaffected by connectivity and increased in response to changes in patch shape—higher edge-to-interior ratio—created by corridors. Corridors promoted biodiversity spillover for native species of the threatened longleaf pine ecosystem being restored in our experiment, but not for exotic species. By extending economically driven spillover concepts from marine fisheries and crop pollination systems, we show how reconnecting landscapes amplifies biodiversity conservation both within and beyond reserve borders.

Title:

Land-use history, historical connectivity, and land management interact to determine longleaf pine woodland understory richness and composition

Author:

Brudvig, L. A.

Damschen, E. I.

Year published:

2011

Publication Type:

Peer-reviewed literature

Abstract:

Restoration and management activities targeted at recovering biodiversity can lead to unexpected results. In part, this is due to a lack of understanding of how site-level characteristics, landscape factors, and land-use history interact with restoration and management practices to determine patterns of diversity. For plants, such factors may be particularly important since plant populations often exhibit lagged responses to habitat loss and degradation. Here, we assess the importance of site-level, landscape, and historical effects for understory plant species richness and composition across a set of 40 longleaf pine Pinus palustris woodlands undergoing restoration for the federally endangered red-cockaded woodpecker in the southeastern United States. Land-use history had an overarching effect on richness and composition. Relative to historically forested sites, sites with agricultural histories (i.e. former pastures or cultivated fields) supported lower species richness and an altered species composition due to fewer upland longleaf pine woodland community members. Landscape effects did not influence the total number of species in either historically forested or post-agricultural sites; however, understory species composition was affected by historical connectivity, but only for post-agricultural sites. The influences of management and restoration activities were only apparent once land-use history was accounted for. Prescribed burning and mechanical overstory thinning were key drivers of understory composition and promoted understory richness in post-agricultural sites. In historically forested sites these activities had no impact on richness and only prescribed fire influenced composition. Our findings reveal complex interplays between site-level, landscape, and historical effects, suggest fundamentally different controls over plant communities in longleaf pine woodlands with varying land-use history, and underscore the importance of considering land-use history and landscape effects during restoration.

Title:

The influence of habitat fragmentation on multiple plant-animal interactions and plant reproduction

Author:

Brudvig, L. A.

Damschen, E. I.

Haddad, N. M.

Levey, D. J.

Tewksbury, J. J.

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

Despite broad recognition that habitat loss represents the greatest threat to the world's biodiversity, a mechanistic understanding of how habitat loss and associated fragmentation affect ecological systems has proven remarkably challenging. The challenge stems from the multiple interdependent ways that landscapes change following fragmentation and the ensuing complex impacts on populations and communities of interacting species. We confronted these challenges by evaluating how fragmentation affects individual plants through interactions with animals, across five herbaceous species native to longleaf pine savannas. We created a replicated landscape experiment that provides controlled tests of three major fragmentation effects (patch isolation, patch shape [i.e., edge-to-area ratio], and distance to edge), established experimental founder populations of the five species to control for spatial distributions and densities of individual plants, and employed structural equation modeling to evaluate the effects of fragmentation on plant reproductive output and the degree to which these impacts are mediated through altered herbivory, pollination, or pre-dispersal seed predation. Across species, the most consistent response to fragmentation was a reduction in herbivory. Herbivory, however, had little impact on plant reproductive output, and thus we found little evidence for any resulting benefit to plants in fragments. In contrast, fragmentation rarely impacted pollination or pre-dispersal seed predation, but both of these interactions had strong and consistent impacts on plant reproductive output. As a result, our models robustly predicted plant reproductive output (r2 = 0.52-0.70), yet due to the weak effects of fragmentation on pollination and pre-dispersal seed predation, coupled with the weak effect of herbivory on plant reproduction, the effects of fragmentation on reproductive output were generally small in magnitude and inconsistent. This work provides mechanistic insight into landscape-scale variation in plant reproductive success, the relative importance of plant-animal interactions for structuring these dynamics, and the nuanced nature of how habitat fragmentation can affect populations and communities of interacting species.

Title:

Vegetation response to midstorey mulching and prescribed burning for wildfire hazard reduction and longleaf pine (Pinus palustris Mill.) ecosystem restoration

Author:

Brockway, D. G.

Outcalt, K. W.

Estes, B. L.

Rummer, R. B.

Year published:

2009

Publication Type:

Peer-reviewed literature

Abstract:

Dense midstorey vegetation, developed during fire exclusion, not only reduces understorey plant diversity and increases the risk of damaging wildfire but also impedes efforts to safely restore prescribed burning in longleaf pine (Pinus palustris Mill.) ecosystems. Our study examined the effects of midstorey reduction on stand structure and plant diversity in a forest treated by mulching alone and also when followed by prescribed fire during the winter, spring or summer. For trees ≥ 5 cm diameter at breast height (d.b.h.), mulching reduced stand density (1220 – 258 trees ha-1) and basal area (24 – 17.7 m2 ha -1) and increased mean d.b.h. (12.8 – 29.2 cm), with the largest reductions in loblolly pine (Pinus taeda L.), sweetgum (Liquidambar styraciflua L.) and oaks (Quercus spp. L.). Removing hardwoods and smaller pines resulted in a decline in tree species richness (8.9 – 4.4). Despite a modest increase in evenness (0.72 – 0.79), tree species diversity (H ′ = 1.32 – 0.84) dynamics were largely driven by changes in richness. While the cover of tree seedlings initially declined from 32.4 to 16.9 per cent, rapid regrowth of hardwoods led to recovery by end of the second growing season. This, along with gains by shrubs, vines, grasses and forbs, resulted in a near doubling of understorey plant cover. Although tree seedling increases were not related to fi re season, peak responses occurred for shrubs and vines after winter fire and spring fire, grasses following winter fire and forbs after summer fire. An increase in species richness (18.7 – 24.5) and decline in species evenness (0.86 – 0.70) produced only a small increase in understorey species diversity (H ′ = 2.31 –2.45). The greater number of understorey species following treatment were less equitably distributed as a result of differential rates of plant growth. While mulching led to a short-term increase in woody and herbaceous understorey plants, prescribed fi re is needed to curtail redevelopment of the woody midstorey and further increase grasses and forbs.

Title:

Influence of reproduction cutting methods on structure, growth and regeneration of longleaf pine forests in flatwoods and uplands

Author:

Brockway, D. G.

Outcalt, K. W.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Though longleaf pine (Pinus palustris Mill.) forests have been primarily managed with even-aged methods, interest is increasing in uneven-aged systems, as a means of achieving a wider range of stewardship goals. Selection silviculture has been practiced on a limited scale in longleaf pine, but difficulty with using traditional approaches and absence of an evaluation across a range of site types has left managers in doubt concerning its suitability. This study was conducted to quantify the effects on stand dynamics of applying single-tree selection, group selection, irregular shelterwood and uniform shelterwood in longleaf pine forests on flatwoods and uplands of the southeastern United States. Selection treatments reduced stand basal area to ~11.5 m2 ha-1 and shelterwood treatments left a basal area of ~5.8 m2 ha-1. In spite of initial decreases in tree density and standing volume, growth rates were normal in all stands (1–5% per year), as were subsequent increases in basal area and tree density. Despite the continuing abundance of saw-palmetto (Serenoa repens W. Bartram) cover and absence of prescribed fire during the eight post-treatment years, significant increases in pine regeneration were observed in all treated stands in the flatwoods. Because of a multi-year drought in the uplands, pine seedling numbers dramatically declined, no matter which reproduction approach was employed. Although seedling numbers eventually began to recover, they were again precipitously depressed by a wildfire in 2013. Even with such losses, sufficient pine seedlings remained in each treatment to foster successful stand regeneration. Single-tree selection produced less overall change in the forest ecosystem than group selection, which caused less alteration than shelterwood treatment. Single-tree selection appears to be an effective way for achieving stand regeneration, while maintaining a continuous canopy cover that aids in the control of woody competitors and supports an array of resource values. Selection silviculture seems to be a lower risk approach for guiding forests along a trajectory of gradual improvement, with adjustments provided by frequent surface fires and periodic tree harvest. Long-term observation will be required to verify that selection can sustain forest ecosystems on sites characterized by differing environments.

Title:

Gap-phase regeneration in longleaf pine wiregrass ecosystems

Author:

Brockway, D. G.

Outcalt, K. W.

Year published:

1998

Publication Type:

Peer-reviewed literature

Abstract:

Naturally regenerated seedlings of longleaf pine are typically observed to cluster in the center of tree fall canopy gaps and be encircled by a wide zone from which they are generally excluded. Twelve representative canopy gaps distributed across 600 ha of a naturally regenerated uneven-agedlongleaf pine forest in the sandhills of north central Florida were examined to determine which aboveground and belowground factors are responsible for development of this seedling exclusionary zone. Within 12 m of adult trees growing along the gap edge, significantly fewer longleaf pine seedlings were present. The canopy of overstory trees, however, extended only 4-5 m into the gap. The relatively open structure of the longleaf pine canopy (57% cover) allowed photosynthetically active radiation (PAR) to be evenly distributed upon the forest floor across each canopy gap. Thus, light avail-ability was not related to pine seedling clustering near gap centers. Significantly greater forest litter mass beneath adult trees (5 Mg ha-1) could result in fires more intense than would be supported by the litter mass near gap centers (2.5 Mg ha-1). However, litter mass was significantly elevated only within 4 m of the gap edge. The fine root biomass within 12 m of the gap edge (3-4.5 Mg ha-1) was two to six times that measured near the gap center and most closely coincided with the width of the seedling exclusionary zone along the margin of each gap. Thus, while the canopy of adjacent adult trees may indirectly influence seedling mortality through deposition of needle litter and greater fire intensity within 4 m of the gap edge, the root systems of these adults also appear to directly compete with seedlings within 12-16 m of the gap edge for limited site resources. To effectively regenerate and sustain longleaf pine wiregrass ecosystems, caution should be used in prescribing single-tree selection harvest methods so as not to create gap openings so small(< 30 m diameter) that intraspecific competition from adult trees totally excludes seedlings. Group selection methods may prove more effective in creating canopy gaps of sizes suitable (>= 40 m diameter) for ensuring that intraspecific competition from adults is maintained at a level which allows for survival and growth of seedlings. Shelterwood and deferment methods may also prove useful where more open canopy conditions are desired. However, the pine seedlings' need for light cannot be used as an appropriate rationale for application of clearcutting methods.

Title:

Influence of deer, cattle grazing and timber harvest on plant species diversity in a longleaf pine bluestem ecosystem

Author:

Brockway, D. G.

Lewis, C. E.

Year published:

2003

Publication Type:

Peer-reviewed literature

Abstract:

Despite a recent slowing in the negative historical trend, losses of naturally-regenerated longleaf pine forests currently continue, largely as a result of conversion to plantations of faster growing pine species. Comparing the impacts of type conversion with silvicultural approaches that maintain longleaf pine and ascertainin,0 their interaction with the influence of other resource management practices, such as grazing, on plant species diversity are essential in discerning the effects of these activities on the long-term sustainability of these ecosystems. A flatwoods longleaf pine bluestem ecosystem, which naturally regenerated following timber harvest during the early 20th century, on the coastal plain of southern Alabama was thinned to a residual basal area of 17 m2/ha or clearcut, windrowed and planted with slash pine (Pinus elliottii) seedlings in 1972 and then fenced in 1977 to differentially exclude grazing by deer and cattle. Neither grazing by deer alone nor deer in combination with cattle significantly altered vascular plant cover or species diversity; however, substantial differences were noted between the understory plant communities in the thinned forests and clearcut areas. Woody understory vegetation steadily increased through time, with woody plant cover in clearcuts (41%) dominated by the tree seedlings of Pinus elliottii and Quercus spp. being greater than that in thinned forests (3 1%) which were dominated by shrubs, principally Ilex glabra. While grass cover dominated by Schizacharium scoparium and Andropogon spp. remained stable (-8 I %), the foliar cover of all forbs declined through time (from 42 to 18%) as woody plant cover increased. Although the overall species richness and diversity declined and evenness increased through time, understory species richness and diversity were consistently higher in thinned forests than in artificially-regenerated clearcuts. Despite a modest short-term decline in this differential, indicating a partial recovery of the clearcut areas over time, the disparity in understory plant diversity between thinned forests and clearcuts persisted for at least a decade. Whether grazing includes domestic cattle or is limited to native ungulates, such as white-tailed deer, we recommend that longleaf pine forests nor be clearcut and replaced by plantations of other pines, if the ecological diversity is to be conserved, high quality habitat is to be maintained and longleaf pine ecosystems are to be sustained.

Title:

Long-term effects of dormant-season prescribed fire on plant community diversity, structure and productivity in a longleaf pine wiregrass ecosystem

Author:

Brockway, D. G.

Lewis, C. E.

Year published:

1997

Publication Type:

Peer-reviewed literature

Abstract:

A flatwoods longleaf pine wiregrass ecosystem, which regenerated naturally following wildfire in 1942, on the Coastal Plain of southern Georgia was treated over a period of four decades with prescribed fire at annual, biennial and triennial intervals during the winter dormant season. Burning caused substantial changes in the understory plant community, with significant reductions in the folk cover of Zlex &bra in the shrub layer resulting in corresponding increases in the cover of Vaccinium myrsinites, Sporobolus cur&ii, Aristida stricta and Andropogon spp. Understory plant species richness, diversity and evenness also increased as a result of periodic fire. Dormant-season burning decreased the cover of litter on the forest floor and significantly increased the standing biomass of A. strictu, S. curtissii, Andropogon spp., all other grasses and all forbs. Recurrent fire also prevented the development of a vigorous midstory, that impedes understory growth and poses a serious fire hazard to the stand. Overstory trees were largely unaffected by burning. Historical light grazing on the site produced no measurable effects on the plant community. Findings suggest that the biennial burning interval results in declines of I. glabru in the shrub layer and litter cover on the forest floor, leading to the largest increases in understory plant species richness and diversity and the biomass productivity of grasses and forbs. Although flatwoods plant communities evolved in environments characterized by growing-season fires of variable frequency, long-term application of dormant-season fire is also recommended as a useful option for sustaining resource values in this and similar longleaf pine wiregrass ecosystems.

Title:

A method for evaluating outcomes of restoration when no reference sites exist

Author:

Brewer, J. S.

Menzel, T.

Year published:

2009

Publication Type:

Peer-reviewed literature

Abstract:

Ecological restoration typically seeks to shift species composition toward that of existing reference sites. Yet, comparing the assemblages in restored and reference habitats assumes that similarity to the reference habitat is the optimal outcome of restoration and does not provide a perspective on regionally rare off-site species. When no such reference assemblages of species exist, an accurate assessment of the habitat affinities of species is crucial. We present a method for using a species by habitat data matrix generated by biodiversity surveys to evaluate community responses to habitat restoration treatments. Habitats within the region are rated on their community similarity to a hypothetical restored habitat, other habitats of conservation concern, and disturbed habitats. Similarityscores are reinserted into the species by habitat matrix to produce indicator (I) scores for each species in relation to these habitats. We apply this procedure to an open woodland restoration project in north Mississippi (U.S.A.) by evaluating initial plant community responses to restoration. Results showed a substantial increase in open woodland indicators, a modest decrease in generalists historically restricted to floodplain forests, and no significant change in disturbance indicators as a group. These responses can be interpreted as a desirable outcome, regardless of whether species composition approaches that of reference sites. The broader value of this approach is that it provides a flexible and objective means of predicting and evaluating the outcome of restoration projects involving any group of species in any region, provided there is a biodiversity database that includes habitat and location information.

Title:

Phosphorus addition reduces invasion of a longleaf pine savanna (Southeastern USA) by a non-indigenous grass (Imperata cylindrica).

Author:

Brewer, J. S.

Cralle, S. P.

Year published:

2003

Publication Type:

Peer-reviewed literature

Abstract:

Imperata cylindrica is an invasive C4 grass, native to Asia and increasing in frequency throughout the tropics, subtropics, and southeastern USA. Such increases are associated with reduced biodiversity, altered fire regimes, and a more intense competitive environment for commercially important species. We measured rates of clonal spread by I. cylindrica from a roadside edge into the interior of two longleaf pine savannas. In addition, we measured the effects of fertilization with nitrogen and phosphorus on clonal invasion of one of these sites. Clonal invasion occurred at both sites and at similar rates. Older portions of an I. cylindrica sward contained fewer species of native pine-savanna plants. Clonal growth rates and aboveground mass of I. cylindrica were reduced by the addition of phosphorus relative to controls by the second growing season at one site. As a group, native species were not affected much by P-addition, although the height of legumes was increased by P addition, and the percent cover of legumes relative to native non-legumes decreased with increasing expected P limitation (i.e., going from P-fertilized to controls to N-fertilized treatments). Clonal invasion was negatively correlated with the relative abundance of legumes in control plots but not in P-fertilized plots. Species richness and percent cover of native plants (both legumes and non-legumes) were dramatically lower in N-fertilized plots than in controls or P-fertilized plots. Species richness of native plants was negatively correlated with final aboveground mass of I. cylindrica in control and P-fertilized plots, but not in N-fertilized plots. The results suggest that I. cylindrica is a better competitor for phosphorus than are native pine-savanna plants, especially legumes, and that short-lived, high-level pulses of phosphorus addition reduce this competitive advantage without negatively affecting native plant diversity. Ratios of soil P to N or native legume to non-legume plant species may provide indicators of the resistance of pristine pine savannas to clonal invasion by I. cylindrica.

Title:

Declines in plant species richness and endemic plant species in longleaf pine savannas invaded by Imperata cylindrica

Author:

Brewer, J. S.

Year published:

2008

Publication Type:

Peer-reviewed literature

Abstract:

Despite the widespread perception that non-native species threaten biodiversity, there are few documented cases of non-native species displacing rare or specialized native species. Here, I examined changes in plant species composition over 5years during patch expansion of a non-native grass, Imperata cylindrica, in longleaf pine flatwoods in Mississippi, USA. I used a multivariate approach to quantify the degree of habitat specialization and geographic range of all species encountered. I examined losses of species collectively as a function of plant height (controlling for initial frequency) and then the relationship between height and the degree of association with longleaf pine flatwoods, disturbed habitats, and the outer Gulf Coastal Plain of the southeastern USA. Patch expansion resulted in dramatic declines in species richness and increases in ground-level shade at both sites in just 3years. Most tall saplings, shrubs, and vines were not endemic to longleaf pine communities and were less likely to be displaced than short herbs, most of which were indicative of longleaf pine communities. These results suggest that invasion of longleaf pine communities by I. cylindrica will likely cause significant losses of short, habitat-specialists and reduce the distinctiveness of the native flora of these threatened ecosystems.

Title:

Restoration increases bee abundance and richness but not pollination in remnant and post-agricultural woodlands

Author:

Breland, S. J. R.

Turley, N. E.

Gibbs, J.

Isaacs, R.

Brudvig, L. A.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Human land use, including agriculture, is a leading contributor to declining biodiversity worldwide and can leave long-lasting legacies on ecosystems after cessation. Ecological restoration is an approach to mitigate these impacts. However, little is known about how animal communities and plant–animal interactions respond to the combined effects of land-use legacies and restoration.We investigated how restoration and agricultural history affect bee (Hymenoptera: Apoidea: Anthophila) communities and pollination function. In 27 paired remnant (no history of agriculture) and post-agricultural longleaf pine (Pinus palustris Mill.) woodlands, we established 4–10 1-ha plots (126 total) and experimentally restored half of them, while the other half were left as unrestored controls. Restoration was accomplished through canopy thinning which reinstates open savanna-like conditions. We collected bees in each plot using a combination of bowl trapping and standardized netting transects. Thinning increased bee abundance by 169% and bee richness by 110%, but agricultural land use had no effect on these variables. Bee community composition was affected by restoration and was marginally affected by agricultural history. To measure pollination function, we conducted a sentinel plant experiment in which potted black mustard (Brassica nigra L.) plants were placed out in a subset of these sites (n = 10) and either bagged to exclude pollinators or left open for pollinator access. Then, we measured fruit and seed set of sentinel plants to compare pollination function among the restoration and land-use history treatments. Seed set and fruit set of sentinel plants were higher in open than bagged plants, indicating that this model system effectively measured pollination, but we found no differences in pollination based on restoration or agricultural history. These results indicate that although pollinator communities may show clear responses to restoration that are largely independent of prior land-use impacts, this does not necessarily translate into differences in pollination function after restoration.

Title:

Preliminary observations on effects of using different stocking rates of meat goats to control understory vegetation in longleaf pine stands

Author:

Bowie, D. D.

Kumi, A. S.

Min, B. R.

Smith, R. C.

Davis, R. J.

Elliot, A. W.

Gurung, N. K.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

The use of goats for clearing longleaf pine (Pinus palustris Mill.) stand undergrowths has potential as an alternative tool to prescribed burning. Objectives of the experiment were to determine the effects of using different stocking rates of meat goats on understory plant biomass height and quantity, understory crown cover density, animal productivity, soil characteristics and damage to pine trees. A 4.86 ha of 8–9 years old longleaf pine stands with 1112 trees/ha was divided into twelve 0.40 ha at Tuskegee, AL. The understudy vegetation contained many volunteer tree species with Broomsedge (Andropogon virginicus L.) being the predominant grass cover. Fifty-four mature Kiko wether goats (initial BW = 48.5 ± 2.5 kg) were allocated randomly to four treatments (0, 3, 6, 9 goats/0.4 ha) with three replications per treatment for 83 days in 2013 according to a completely randomized block design. The data was analyzed using the GLM procedure of SAS. The tree damage was monitored. Results showed that both initial and the final soil bulk density and soil compaction, plant biomass heights and quantity were not significantly different (P[0.05) among treatments. Average daily BW gains were not significantly different (P = 0.76) but daily gains were close to zero. The combined final crown cover density percent at 2.0 m decreased linearly (P\0.05) with increasing stocking rates. The tree damage was minimal even at the highest stocking rates. The results suggest that goats have potential to manage understory vegetation under longleaf pines.

Title:

The economic impact of green-up contraints in the southeastern United States

Author:

Boston, K.

Bettinger, P.

Year published:

2001

Publication Type:

Peer-reviewed literature

Abstract:

Green-up, or adjacency, requirements are a common constraint in forestry. The American Forest and Paper Association has developed a Sustainable Forestry Initiative that includes a green-up constraint which limits the average clearcut opening to 48 ha for 3 years or until the average height of the regenerated trees is >1.4 m. In addition to constraining the average clearcut size, many forestry companies in the southeastern USA voluntarily limit their maximum clearcut size to between 60 and 90 ha. In this research, a heuristic algorithm was used to develop tactical forest plans that consider both the maximum and average clearcut sizes. Economic effects of the green-up constraints were estimated for situations where intensive management can reduce the length of the green-up time from 3 to 2 years on a 21 600 ha ownership in Georgia (USA). For a 60-ha maximum opening size, this reduction in green-up time from 3 to 2 years resulted in an additional US$ 66 600 in present net worth (PNW) over a 10-year analysis period. This corresponds to a US$ 10 per harvested ha, or a 0.8% increase in PNW. The bene®t gained by reducing the length of the green-up period is less with a 90-ha maximum clearcut size, where PNW increases by US$ 45 600, or US$ 6.70 per harvested ha, a 0.5% increase. While the total volume per period was near the volume goal produced by a strategic forest plan, the spatial restrictions and the desire to maximize net present value resulted in lower volume of timber products (sawlogs and chip-and-saw logs) from older forest stands. A sensitivity analysis showed that an increase in price or yield further reduced the economic incentive for the reduction of the length of the green-up constraint. As price or volume decreased below expectations, however, the incentive to use intensive forest management practices to reduce the length of the green-up constraint became more attractive, since the differences between a 2-year and 3-year green-up time requirement may be large enough to pay for more intensive management practices.

Title:

Dynamic site index equation for thinned stands of even-aged natural longleaf pine

Author:

Lauer, D. K.

Kush, J. S.

Year published:

2010

Publication Type:

Peer-reviewed literature

Abstract:

A dynamic site equation derived using the generalized algebraic difference approach was developed for thinned stands of natural longleaf pine (Pinus palustris Mill.) in the East Gulf region of the United States using 40 years of measurements on 285 permanent plots. The base model predicts height growth of trees once they reach 4.5 ft and was fit using a varying parameter for each tree and global parameters that are constant for all 3,267 trees. Parameters were estimated in one step using the dummy variable approach and a first-order autoregressive error term to account for serial correlation. The final base-age invariant equation allows the user to specify the number of years required for trees to reach 45 It in height.

Title:

Variability in fire prescriptions to promote wildlife foods in the longleaf pine ecosystem

Author:

Lashley, M. A.

Chitwood, M. C.

Harper, C. A.

DePerno, C. S.

Moorman, C. E.

Year published:

2015

Publication Type:

Peer-reviewed literature

Abstract:

Prescribed fire is commonly used to restore and maintain the longleaf pine (Pinus palustris Mill.) ecosystem (LLPE). A key function of the LLPE is the provisioning of food for wildlife. Despite the plethora of literature evaluating the effects of fire season and fire-return interval on plant community dynamics, little attention has been given to the response of wildlife foods to fire season or fire-return interval. We measured the availability of key wildlife foods (fleshy fruit [i.e., seed containing a nutritious pericarp] and understory plant biomass) in upland pine forest following dormant-season (December–February) and growing-season (April–June) fires in a chronosequential design. Also, we quantified the relative contributions of the upland hardwood and bottomland hardwood forest types, which often are intentionally suppressed in the LLPE. In 2011 and 2012, we measured understory leafy biomass, biomass of forages selected by whitetailed deer (Odocoileus virginianus Zimm.), and soft mast production chronosequentially in relation to years-since-fire, fire season, and vegetation type in the LLPE at Fort Bragg Military Installation, North Carolina, USA. Understory leafy biomass increased in upland pine and hardwood forests as years-since-fire increased until two years post fire. Selected forages decreased in upland pine forest and increased in upland hardwood forest as time-since-fire increased. In upland pine forests burned during the growing season, 94% of the fruit was detected two years after fire, 6% one year after fire, and 0% the same year as fire. In June, fruit density was greatest in bottomland hardwood forest; in July, fruit density was greatest in dormant-season burned upland pine forest; in August, fruit density was greatest in upland hardwood forest; and in September, fruit density was greatest in upland hardwood and bottomland hardwood forest. Overall summer fruit density (i.e., the sum of fruit density detected each month) was greatest in upland hardwood forest. Understory leafy biomass and deer-selected forages were stable in bottomland hardwood forest because they were not burned, thereby providing a relatively high and stable availability from year to year. Our data demonstrate the importance of diversity in fire season and frequency, and diversity in vegetation types to promote key wildlife foods in the LLPE.

Title:

Subtle effects of a managed fire regime: a case study in the longleaf pine ecosystem

Author:

Lashley, M. A.

Chitwood, M. C.

Prince, A.

Elfelt, M. B.

Killburg, E. L.

DePerno, C. S.

Moorman, C. E.

Year published:

2014

Publication Type:

Peer-reviewed literature

Abstract:

Land managers often use fire prescriptions to mimic intensity, season, completeness, and return interval of historical fire regimes. However, fire prescriptions based on average historical fire regimes do not consider natural stochastic variability in fire season and frequency. Applying prescribed fire based on averages could alter the relative abundance of important plant species and structure. We evaluated the density and distribution of oak (Quercus spp.) and persimmon (Diospyros virgiana) stems and mast after 22 yr of a historical-based growing-season fire prescription that failed to consider the variability in historical fire regimes. We randomly established 30 25-m transects in each of 5 vegetation types and counted reproductively mature oak and persimmon stems and their fruits. In upland longleaf pine (Pinus palustris) stands, this fire regime killed young hardwood trees, thereby decreasing compositional and structural heterogeneity within the upland pine vegetation type and limiting occurrence of the upland hardwood vegetation type. Acorns and persimmons were disproportionately distributed near firebreaks within low intensity fire transition zones. Mast was maintained, though in an unnatural distribution, as a result of an elaborate firebreak system. Our data indicate managed fire regimes may fail to mimic spatial distribution, frequency, and intensity of historical disturbances even when the fire prescription is based on empirical reference fire regimes. To maximize structural heterogeneity and conserve key ecosystem functionality, fire prescriptions should include variations in frequency, season, application method, and fire weather conditions rather than focusing on an average historical fire regime.

Title:

Effects of prescribed fire on the herpetofauna of a southern Mississippi pine savanna

Author:

Langford, G. J.

Borden, J. A.

Major, C. S.

Nelson, D. H.

Year published:

2007

Publication Type:

Peer-reviewed literature

Abstract:

Despite the recent popularity of prescribed burns in the southeast USA, little research is available on the effects of prescribed fire on herpetofauna in the western coastal plain (Gulf Coast, USA). We assessed the effects of a restoration prescribed burn on herpetofauna and composed an inventory of amphibians and reptiles on the Grand Bay National Estuarine Research Reserve (GBNERR) and surrounding Grand Bay National Wildlife Refuge (GBNWR), Jackson County, Mississippi. We used visual encounter surveys (VES), minnow traps, and polyvinyl chloride (PVC) tubes to sample herpetofauna. We recorded 429 individuals and 29 species from January-June, 2004. We found greater numbers of herpetofauna in burned than unburned stands, while species diversity indices were equal between burn treatments. Our results provide the first herpetological survey of the reserve, providing a baseline for monitoring herpetofauna population and community trends.

Title:

Longleaf pine forests of the Southeast: requiem or renaissance?

Author:

Landers, J. L.

Van Lear, D.

Boyer, W. D.

Year published:

1995

Publication Type:

Peer-reviewed literature

Title:

Longleaf pine: a sustainable approach for increasing terrestrial carbon in the southern United States

Author:

Kush, J. S.

Meldahl, R. S.

McMahon, C. K.

Boyer, W. D.

Year published:

2004

Publication Type:

Peer-reviewed literature

Abstract:

Natural communities dominated by longleaf pine (Pinus palustris Mill.) once covered an estimated two thirds of the forested area in the southeastern United States. Today, less than 1.2 million ha remain. However, over the past 10-15 years, public land managers have begun to restore many longleaf pine forests. More recently incentive programs have prompted reforestation and afforestation promgrams on onindustrial private lands. These activities have been facilitated by improved longleaf regeneration technology and by expanded educational and outreach efforts. In the South, there is also a growing trend towards longer rotations due to changes in wood/fiber markets and prices. These trends suggest a new strategy to increase terrestrial carbon storage in the southeastern United States in a way that provides many simultaneous ecological and economic benefits. For example, longleaf pine is a long-lived species with a low mortality rate. Among the southern pine species, it has a high specific gravity and can tolerate a wide variety of habitats. Longleaf pine is better able to sustain growth at older ages (over 150 years) and is tolerant to fire and many insects and diseases. Recent research also indicates that longleaf pine managed for longer rotations outperforms other commercial southern pine species on most sites and might better adapt to future climate scenarios with higher temperatures and higher atmospheric CO2 levels. Moreover, the higher-value, longer-lasting wood products derived from longleaf pine forests will continue to store carbon over long time periods.

Title:

Composition of a virgin stand of longleaf pine in south Alabama

Author:

Kush, J. S.

Meldahl, R. S.

Year published:

2000

Publication Type:

Peer-reviewed literature

Abstract:

The Flomaton Natural Area is a virgin stand of longleaf pine located in Escambia County, Alabama. Fire has been absent for at least the past 45 years from the stand. Efforts are underway to restore this fire-dependent ecosystem through the re-introduction of fire. This paper presents data collected in advance of the re-introduction of fire. A substantial hardwood understory and midstory have developed and a thick litter layer has accumulated in the absence of fire. Longleaf pine (Pinus palustris) regeneration and herbaceous vegetation are almost nonexistent. Considering all trees>1.25 em DBH, longleaf pine averages 309 stemslha and 19 m2/ha, or 65% of total stand basal area. The predominant hardwood species are water oak (Quercus nigra), laurel oak (Q. laurifolia), southern red oak (Q. falcala) , and black cherry (Prunus seratinaJ. Together these hardwoods average 929 stemslha and 6.5 m'/ha, or 22% of the total stand basal area. Other pines and hardwoods comprise 8% and 5% of total stand basal area, respectively. Considering only saplings (1.25 to 12.7 em DBH), longleaf accounts for only 11% and the four major hardwoods 64% of total sapling basal area.

Title:

White-tailed deer use of overstory hardwoods in longleaf pine woodlands

Author:

Kroeger, A. J.

Moorman, C. E.

Lashley, M. A.

Chitwood, M. C.

Harper, C. A.

DePerno, C. S.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Restoration of the longleaf pine ecosystem is a conservation priority throughout the southeastern United States, but the role of hardwoods in providing food and cover for wildlife within this system is poorly understood. We investigated white-tailed deer (Odocoileus virginianus) movement and habitat selection relative to overstory hardwood distribution in a longleaf pine ecosystem at Fort Bragg Military Installation in the Sandhills physiographic region of North Carolina from March 2011–July 2013. We monitored GPS-collared female white-tailed deer and used generalized linear mixed models and step-selection functions to determine the influence of overstory composition and understory cover on seasonal white-tailed deer habitat selection. During fall and winter, deer selection increased with increasing upland hardwood overstory until reaching an upper threshold (12% and 7%; respectively) where increasing cover of upland hardwoods no longer increased selection. Also, in the fall and winter, deer selected areas with greater bottomland hardwood overstory until an upper threshold of 33% bottomland hardwood overstory was reached. In the spring, deer selected areas with<22% upland hardwood overstory. The effect size of understory cover, defined as lidar-classified vegetation with height<2 m, was larger than any other variable, regardless of season, and deer consistently selected areas with 20–75% understory cover. When managing longleaf pine woodlands for white-tailed deer, our results indicate maintaining a well-developed woody understory with 20–50% canopy closure is important, ideally with mature upland hardwood overstory cover between 4 and 12% to ensure mast production in fall and winter.

Title:

Long-duration soil heating resulting from forest floor duff smoldering in longleaf pine ecosystems

Author:

Kreye, J. K.

Varner, J. M.

Kobziar, L. N.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Prescribed fire is commonly used in southeastern US forests and is being more widely applied in fire-prone ecosystems elsewhere. Research on direct effects of burning has focused on aboveground impacts to plants with less attention to belowground effects. We measured soil heating during experimental burns in longleaf pine sandhill and flatwoods ecosystems in the southeastern US. Soil heating was minimal in frequently burned sites. Where fire had been excluded for several decades, however, we detected substantial soil heating sustained for considerable durations. Long-duration heating was most prominent where accumulated forest floor duff (Oe and Oa organic horizons) was deepest, particularly at the base of mature pines in long-unburned sites. Temperatures potentially lethal to plant tissues (≥60°C) were sustained for several hours as deep as 10 cm near pines in flatwoods sites. Sustained temperatures ≥300°C, when impacts to soil nutrients can occur, were observed for up to 35 min at mineral soil surfaces. Patterns of heating were similar in long-unburned sandhill sites; however, temperatures were generally lower and durations more brief. Heat transfer resulting from smoldering in forest floor duff deserves further attention to predict mineral soil heating, forecast fire effects, and inform restoration efforts in fire-prone ecosystems.

Title:

Pine cones facilitate ignition of forest floor duff

Author:

Kreye, J. K.

Varner, J. M.

Dugaw, C. J.

Cao, J.

Szecsei, J.

Engber, E. A.

Year published:

2013

Publication Type:

Peer-reviewed literature

Abstract:

The ignition and combustion of forest floor duff are poorly understood yet have been linked to soil heating and overstory tree mortality in many temperate coniferous forests. Research to date has focused on the characteristics of duff that facilitate ignition and spread, including fuel moisture, mineral content, and depth. Field observations suggest that the presence of pine cones on and within the forest floor might facilitate ignition of intermixed forest floor fuels. We investigated the effect of cone fuel additions on the ignition of underlying forest floor from fuels collected in long-unburned longleaf pine (Pinus palustris Mill.) forests in northern Florida, USA. Fuels were wetted to threshold gravimetric moisture contents to evaluate the relative effect on ignition. In stark contrast to fuel beds without cones, in which duff ignition only occurred in 17% of samples, those with cones added ignited the underlying duff 94% of the time. Flame heights were 40% taller and flaming duration was 47% longer in fuel beds with cones. Where present, pine cones act as vectors of ignition for forest floor fuels, and their role in fires deserves more attention to enhance our understanding of forest floor combustion. 

Title:

Fire generates spatial gradients in herbivory: an example from a Florida sandhill ecosystem

Author:

Knight, T. M.

Holt, R. D.

Year published:

2005

Publication Type:

Peer-reviewed literature

Title:

Prescribed fire affects diurnal vertebrate use of gopher tortoise (Gopherus polyphemus) burrows in a longleaf pine (Pinus palustris) forest

Author:

Knapp, D. D.

Howze, J. M.

Murphy, C. M.

Dziadzio, M. C.

Smith, L. L.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Frequent fires are essential for maintaining the Longleaf Pine (Pinus palustris) ecosystem and are beneficial to the Gopher Tortoise (Gopherus polyphemus), a Longleaf Pine specialist that excavates burrows used by many commensal species. Presumably, burrows offer important refugia to commensals both during and after fires, but no published studies have confirmed this. Therefore, the objective of this study was to examine how prescribed fire influences diurnal vertebrate use of Gopher Tortoise burrows. We deployed trail cameras in 46 burrows before a prescribed fire and monitored vertebrate activity until we removed cameras 11 d after the fire. We compared vertebrate burrow use before and during the prescribed fire and also used data from a previous study to compare vertebrate use of burrows on an unburned site to that of our recently burned site. We observed one vertebrate commensal at 43 monitored burrows (0.02 vertebrates per camera) on the day before the burn and nine vertebrates at 41 burrows (eight species, 0.22 vertebrates per camera) during the burn. In addition, we observed 8.5 times more vertebrates using burrows at the recently burned site than at an unburned site (51 individuals of seven species versus six individuals of three species, respectively). Our results suggest that Gopher Tortoise burrows offer important diurnal refugia to commensals from direct (risk of mortality) and indirect (perceived risk of predation and/or injury) effects of fire. Additional studies would be beneficial on nocturnal vertebrate burrow use, longer-term trends as vegetative cover regenerates following fire, and relative importance of other refugia for vertebrates.

Title:

Fire effects on a fire-adapted species: response of grass stage longleaf pine seedlings to experimental burning

Author:

Knapp, B. O.

Pile, L. S.

Walker, J. L.

Wang, G. G.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Background: Longleaf pine (Pinus palustris Mill.) seedlings have a morphological “grass stage” that is considered to be an adaptation to frequent surface fire regimes. However, fire can kill longleaf pine seedlings and thus may play an important role in longleaf pine regeneration dynamics. We used a prescribed burn simulation tool designed to treat individual grass stage longleaf pine seedlings with controlled delivery of fire treatments and then measured survival and growth responses through two growing seasons. Naturally regenerated grass stage longleaf pine seedlings were randomly selected from three size classes and each assigned one of four treatments (Control, no treatment; Clip, mechanical needle removal; LB, a low-temperature burn treatment; or HB, a high-temperature burn treatment) in both the dormant season (January) and the growing season (May). Results: Seedlings greater than 15 mm root collar diameter had greater than 0.5 probability of survival after the first growing season in the HB treatment, regardless of the season of treatment application, and seedlings across all sizes had greater than 0.6 probability of survival in the LB treatment after the first growing season. The growing season treatment application resulted in additional mortality during the second growing season, across all seedling size classes, which was not observed in the dormant season application. Burning reduced root collar growth through two growing seasons, likely due to needle mortality and the subsequent prioritization of growth to needle production rather than to root or stem growth. Conclusions: Our results suggest that the interplay between seedling size and fire intensity likely contributes to the success of longleaf pine natural regeneration and that seedling size should be considered when scheduling the first burn following planting of longleaf pine seedlings.

Title:

Effects of site preparation treatments on early growth and survival of planted longleaf pine (Pinus palustris Mill.) seedlings in North Carolina

Author:

Knapp, B. O.

Wang, G. G.

Walker, J. L.

Cohen, S.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

We tested the effects of eight site preparation treatments on early growth and survival of container-grown longleaf pine (Pinus palustris Mill.) seedlings. Treatments included an untreated check, six combinations of two initial vegetation control treatments (chopping or herbicide) with three planting site conditions (flat [no additional treatment], mounding, or bedding), and a more intense treatment consisting of chopping, herbicide, and bedding. A11 plots were prescribed burned after site preparation and before planting. Seedling survival was not significantly different among treatments at either 12 (p = 0.768) or 20 (p = 0.881) months after planting. Both bedding and mounding increased root collar diameter after 20 months when compared to flat treatments (p 5 0.002). Between the vegetation control treatments, herbicides increased root collar diameter growth over chopping ( p = 0.002) while chopping did not significantly differ from the check. The most root collar growth occurred on the chopping/herbicide/bedding and herbicide bedding treatments, with the least on the flat (check) and chopping/flat treatments. The percentage of seedlings in height growth 20 months after planting was higher on bedding and mounding treatments when compared to flat treatments ( p < 0.003). Herbicide was also significantly better than chopping with respect to the percentage of seedlings in height growth (p = 0.016). The treatments with the most seedlings in height growth were chopping/herbicide/bedding followed by herbicide/bedding and herbicide/mounding.

Title:

Prescribed fire effects on Pinus palustris woodland development after catastrophic wind disturbance and salvage logging

Author:

Kleinman, J. S.

Goode, J. D.

Hart, J. L.

Dey, D. C.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Scientifically informed strategies to manage naturally disturbed forests are critical to support the sustained provisioning of ecosystem goods and services. In fire-adapted ecosystems, catastrophic canopy removal can disrupt surface fuel continuity and challenge the continued use of low-intensity prescribed fire. Although salvage logging is used globally after natural disturbance events, little information is available on how salvage logging interacts with subsequent use of prescribed fire. This study investigated the impacts of operational-scale prescribed fire on Pinus palustris (longleaf pine) stand development in areas differentially impacted by an April 2011 EF3 tornado and a subsequent salvage logging operation. Twenty 0.04-ha nested plots were systematically established in mature, wind-disturbed, and salvage-logged sites (n = 60) to measure seedlings, saplings, woody fuels, organic litter, and mineral soil before and after prescribed fire. Prescribed fire-induced fine fuel consumption, mineral soil exposure, and substantial sapling density reductions were observed throughout the treatment area. Prescribed fire effects were not apparently impacted by salvage logging, which did not alter the amount of fine fuels available for prescribed fire consumption. Despite overall sapling density reductions, fire-resistant P. palustris saplings exhibited increased densities on wind-disturbed and salvage-logged sites. Pinus palustris seedlings, however, exhibited marked post-fire reductions, which contrasted with a strong resprouting response observed among top-killed hardwood species. Concerning woody plant recovery, this study indicated that salvage logging was not detrimental to P. palustris stand development and that prescribed fire effectively enhanced recovery in unlogged and logged wind-disturbed sites.

Title:

Vascular flora of longleaf pine woodlands after wind disturbance and salvage harvesting in the Alabama Fall Line Hills

Author:

Kleinman, J. S.

Hart, J. L.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

The Oakmulgee District of the Talladega National Forest is the largest remnant of the endangered longleaf pine (Pinus palustris) ecosystem in Alabama. A partial floristic survey using nested plots and survey plots was conducted May–July 2016 in longleaf pine woodlands of the Oakmulgee District that were differentially impacted by a 27 April 2011 EF3 tornado and a subsequent salvage harvesting operation. Vascular plants were identified and ranked by frequency of occurrence (rare, occasional, common, and abundant) in three disturbance categories: undisturbed, wind-disturbed, and compound-disturbed (wind-disturbed and salvage-harvested). Overall, 192 plant taxa in 68 families and 137 genera were documented. Plant taxonomic richness was lowest on undisturbed sites (90 taxa), greatest on wind-disturbed sites (160 taxa), and reduced on compound-disturbed sites (126 taxa). Although salvage harvesting reduced taxonomic richness, 46 of the 48 plant taxa unique to unharvested wind-disturbed sites were rare (occurred on <10% of nested plots). Moreover, undisturbed sites had only nine unique taxa, of which eight were rare. Decisions on whether to salvage harvest must consider the ecological significance of these rare plants. Wind- and compound-disturbed areas may recover toward predisturbance conditions, and the floristic list presented here provides the baseline to monitor this succession. The documented floristic composition also provides insight on short-term responses of vascular plants to differential disturbance impacts in an understudied region of the longleaf pine ecosystem.

Title:

Changes in tree canopy, groundcover, and avian community following restoration of a montane longleaf pine woodland

Author:

Klaus, N. A.

Rush, S. A.

Weitzel, S. L.

Holdrege, M. C.

Year published:

2020

Publication Type:

Peer-reviewed literature

Abstract:

Fire suppression and hardwood encroachment are two of the most significant threats to the imperiled, fire-dependent montane longleaf pine ecosystem. We examined the effects of restoration of a montane longleaf pine forest in Paulding County, Georgia, U.S.A. on tree canopy, groundcover and bird communities over a decade. The restoration included a program of prescribed fire and selective thinning to reduce tree canopy density and reduce or remove offsite species. Several conservation goals were met including the recovery of characteristic tree composition and groundcover. Birds responded with sharp increases in richness and abundance, with many shrub and woodland dependent species of high conservation value detected post-restoration. Our research demonstrates these sites are easily restorable and such projects will likely yield significant gains for conservation.

Title:

Specialist and generalist amphibians respond to wetland restoration treatments

Author:

Klaus, J. M.

Noss, R. F.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Available habitat within a landscape is often more limited for specialist species than for generalists. Therefore, specialists are potentially more vulnerable to extinction. The goal of our study was to better understand the ephemeral wetland habitat associations of specialist and generalist amphibians within a longleaf pine landscape in the southeastern United States. We also sought to determine specialist (e.g., oak toad [Anaxyrus quercicus], Maybee’s salamander [Ambystoma maybeei], pine woods treefrog [Hyla femoralis], carpenter frog [Lithobates virgatipes]) and generalist (e.g., spotted salamander [Ambystoma maculatum], Cope’s gray treefrog [Hyla chrysoscelis], southern leopard frog [Lithobates sphenocephalus]) species’ responses to specific habitat restoration treatments. From 2005–2010, we examined the relationship between aquatic specialist and generalist amphibian species occupancy and wetland vegetation structure. We measured vegetation and amphibian responses to prescribed fire and vegetation mulching (a fire surrogate), plus a combination of mulching and burning. Untreated controls were wetlands that had not burned for 4–15 years. We combined data from this study and a previous study to elucidate patterns in amphibian assemblages in relation to fire history. Specialist relative species richness was highest when canopy openness was high and leaf litter depth was low, conditions best achieved by mulching plus burning. Some specialist species were not detected in wetlands with >8 years since fire, and some generalist species were not detected in wetlands with <2 years since fire, indicating that as vegetation structure changes with time since fire, there is a corresponding shift in the amphibian assemblage. Important patterns in species distributions can be overlooked if relationships to environment and responses to habitat change are too generalized and do not account for shifts in community composition. For conservation of longleaf pine specialist species, we recommend that uplands continue to be prescribed-burned on a 1–3-year return interval. Burning should occur during the early growing season when possible tomaximize the probability that wetland basins burn. In cases where species of high conservation value are at imminent risk of extinction, we recommend a combination of mulching and burning to most quickly restore suitable habitat structure.

Title:

Fire history of a Georgia montane longleaf pine (Pinus palustris) community

Author:

Klaus, N. A.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Montane longleaf pine forests, woodlands, and savannas are endangered, firedependent ecosystems of the Piedmont, Ridge and Valley, Appalachian, and Cumberland Plateau physiographic provinces of Georgia, Alabama, and North Carolina. Compared to other longleaf pine ecosystems, e.g., longleaf pinewiregrass, little has been published about montane longleaf pine ecosystems. Understanding the historic fire regimes that once maintained montane longleaf pine ecosystems is an important first step toward achieving restoration and conservation goals for this ecosystem. I used two approaches to investigate historic fire regimes: 1) a dendrochronological study of fire scars on Sprewell Bluff Wildlife Management Area and 2) calculations of the average fire tolerance of tree species recorded on 1820s land lottery maps and 2005 surveys. Three distinct periods of fire history were revealed: pre-1840, with an average fire interval of 2.6 years; 1840–1915, with an average fire interval of 1.2 years; and 1915–present, with an average fire interval of 11.4 years. Season of fire differed between periods with all seasons of fire common prior to 1840, mostly winter fires from 1840 to 1915, and mostly spring and early summer fires from 1915 to the present. Land lottery data suggested montane longleaf ecosystems of the 1820s were most similar in fire tolerance to areas of longleafwiregrass, as compared to several other historic Georgia forest types. Modern forests had much lower scores of fire tolerance. Differences in species composition accounted for these changes in scores; historic montane longleaf ecosystems had larger components of pine (Pinus spp.), post oak (Quercus stellate Wangenh.), and blackjack oak (Q. marilandica Muenchh.), while modern forests had higher densities of chestnut oak (Q. prinus Willd.) and hickory (Carya spp.). My results suggest a fire return interval of two to three years is needed to halt the continued loss of the montane longleaf pine ecosystem.

Title:

Productivity and species richness in lonfleaf pine woodlands: resource-disturbance influences across an edaphic gradient

Author:

Kirkamn, L. K.

Giencke, L. M.

Taylor, R. S.

Mitchell, R. J.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

This study examines the complex feedback mechanisms that regulate a positive relationship between species richness and productivity in a longleaf pine-wiregrass woodland. Across a natural soil moisture gradient spanning wet-mesic to xeric conditions, two large scale manipulations over a 10-yr period were used to determine how limiting resources and fire regulate plant species diversity and productivity at multiple scales. A fully factorial experiment was used to examine productivity and species richness responses to N and water additions. A separate experiment examined standing crop and richness responses to N addition in the presence and absence of fire. Specifically, these manipulations addressed the following questions: (1) How do N and water addition influence annual aboveground net primary productivity of the midstory/overstory and ground cover? (2) How do species richness responses to resource manipulations vary with scale and among functional groups of ground cover species? (3) How does standing crop (including overstory, understory/midstory, and ground cover components) differ between frequently burned and fire excluded plots after a decade without fire? (4) What is the role of fire in regulating species richness responses to N addition? This long-term study across a soil moisture gradient provides empirical evidence that species richness and productivity in longleaf pine woodlands are strongly regulated by soil moisture. After a decade of treatment, there was an overall species richness decline with N addition, an increase in richness of some functional groups with irrigation, and a substantial decline in species richness with fire exclusion. Changes in species richness in response to treatments were scale-dependent, occurring primarily at small scales (≤10 m2). Further, with fire exclusion, standing crop of ground cover decreased with N addition and non-pine understory/midstory increased in wet-mesic sites. Non-pine understory/midstory standing crop increased in xeric sites with fire exclusion, but there was no influence of N addition. This study highlights the complexity of interactions among multiple limiting resources, frequent fire, and characteristics of dominant functional groups that link species richness and productivity.

Title:

Predicting plant species diversity in a longleaf pine landscape

Author:

Kirkman, L. K.

Goebel, P. C.

Palik, B. J.

West, L. T.

Year published:

2004

Publication Type:

Peer-reviewed literature

Abstract:

In this study, we used a hierarchical, multifactor ecological classification system to examine how spatial patterns of biodiversity develop in one of the most species-rich ecosystems in North America, the fire-maintained longleaf pine-wiregrass ecosystem and associated depressional wetlands and riparian forests. Our goal was to determine which landscape features are important controls on species richness, to establish how these constraints are expressed at different levels of organization, and to identify hotspots of biological diversity for a particular locality. We examine the following questions: 1) How is the variance in patterns of plant species richness and diversity partitioned at different scales, or classification units, of the hierarchical ecosystem classification developed for the study area? 2) What are the compositional similarities among ecosystem types? 3) For our study area, what are the sites expected to harbour highest species richness? We used a spatially explicit map of biodiversity to project abundance of species-rich communities in the landscape based on a previously developed ecological classification system for a lower Gulf Coastal Plain landscape. The data indicate that high species richness in this ecosystem was found in sites with frequent fire and high soil moisture. Sites in fire-maintained landscapes with lower frequency of fire were associated with geomorphological characteristics, suggesting a dependence of the diversity-disturbance relationship with soil type. With more frequent fire on some sites, high diversity shifts from canopy component to ground flora, with an overall increase in total species richness. Our approach demonstrates how potential species richness can be identified as a restoration goal and that multiple vegetation endpoints may be appropriate vegetation objectives. We identify basic management needs for the maintenance of biodiversity in this ecosystem that can he derived from an understanding of the combination of factors that most strongly predict diverse plant communities.

Title:

Conservation management of Pinus palustris ecosystems from a landscape perspective

Author:

Kirkman, L. K.

Mitchell, R. J.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

Question: Do case studies from silvicultural and restoration studies and applied conservation management in second-growth Pinus palustris stands provide unique insights for conservation models? Methods: A review of management paradigms that conserve the high biological diversity and rare species, drawn from characteristics in both second-growth and old-growth stands, is presented for fire-maintained Pinus palustris (longleaf pine) forests. Results: A common assumption that old-growth stands provide the primary information for the development of conservation management strategies de-emphasizes lessons learned from second-growth and restoration studies. Primary conservation management goals for the Pinus palustris ecosystem include the perpetual regeneration of the fire-maintained forest and conservation of the characteristically high biological diversity and rare species. Several attributes, such as a sustained population of Picoides borealis (red-cockaded woodpecker), Aristida stricta (wiregrass)-dominated ground cover, and undisturbed upland-wetland ecotones, can predict a diverse and ecologically functional ecosystem. Such indicators are linked to critical structural and functional features of the system and reflect previous land management histories that suggest sustainable approaches. Conclusions: A traditional definition of ‘old-growth’ relying on overstorey may be limited in describing important features of healthy, diverse Pinus palustris ecosystems. Some characteristics are significantly more important for maintenance of diversity than age of the trees and these features may be present in old- or second-growth forests. We advocate that the management history, structural characteristics and landscape context of stands that harbour desirable conservation attributes (red-cockaded woodpeckers, wiregrass, gopher tortoises and undisturbed upland-wetland ecotones) can be used as indicators to identify important conservation and forest management principles.

Title:

Hardwood management and restoration of longleaf pine ecosystems may affect raccoon daytime resting sites

Author:

Kirby, R. B.

Muller, L. I.

Chamberlain, M. J.

Conner, L. M.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Fire-maintained Pinus palustris (longleaf pine) ecosystems are species rich and considered a top conservation priority in the southeastern United States. Ground-nesting species such as Gopherus polyphemus (gopher tortoise) and Colinus virginianus (northern bobwhite) thrive in longleaf ecosystems. However, the generalist carnivore Procyon lotor (raccoon) is a significant predator of these endemic ground nesters. In forested ecosystems, raccoons prefer hardwood-dominated habitats. Removal of hardwood trees, which is a common longleaf pine ecosystem restoration tool, affects habitat use of this predator.We examined 269 daytime resting sites (DRS) associated with 31 radio-collared adult raccoons (18 M, 13 F) during 2014–2015 on a longleaf pine-dominated site in southwestern Georgia. We developed 26 a priori models using an information theoretic approach to evaluate factors affecting use of DRS by raccoons. The top two models (?AIC<2) had combined model weights of 0.75 and contained tree diameter, tree type, presence of nearby hardwood, and distances to pine, hardwood, mixed forest, and agriculture as predictors. However, the only informative variables were tree type and tree diameter. Raccoons used DRS in all available forest types, but were less likely to use pine trees (n=7) relative to hardwoods (n=247), and there was a positive relationship with tree diameter. Females used smaller trees farther from agriculture and primary roads, and were closer to wetlands than those used bymales. Hardwood removal fromwithin longleaf pine ecosystem affects habitat use of this predator, specifically DRS.

Title:

The influence of financial incentive programs in promoting sustainable forestry on the nation’s family forests

Author:

Kilgore, M. A.

Green, J. L.

Jacobson, M. G.

Straka, T. J.

Daniels, S. E.

Year published:

2007

Publication Type:

Peer-reviewed literature

Abstract:

Financial incentive programs were evaluated to assess their contribution to promoting sustainable forestry practices on the nation's family forests. The evaluation consisted of an extensive review of the literature on financial incentive programs, a mail survey of the lead administrator of financial incentive programs in each state forestry agency, and focus groups with family forest owners in four regions of the country. The study found that financial incentive programs have limited influence on forest owners' decisions regarding the management and use of their land. Family forest owners viewed one-on-one access to a forester or other natural resource professional to "walk the land" with them and discuss their management alternatives as the most important type of assistance that can be provided. Recommendations for increasing the effectiveness of financial incentive programs in promoting sustainable forestry are discussed.

Title:

Raising goats in the southern-pine silvopasture system: challenges and opportunities

Author:

Karki, U.

Karki, Y.

Khatri, R.

Tillman, A.

Poudel, S.

Gurung, N.

Kumi, A.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Pasture-based goat operation is popular among small-scale farmers; however, it may be challenging when forage availability is limited. Grazing opportunity can be increased by developing silvopastures after thinning pine plantations. To successfully manage silvopastures, it is important to understand animals’ interaction with trees. The objective of this study was to evaluate the use of goats in the southern pine silvopasture system. Studies were conducted at two sites: Atkins Agroforestry Research and Demonstration Site, Tuskegee (Site 1), and Plantersville Silvopasture Demonstration Site, Plantersville, Alabama (Site 2). Site 1 consisted of six acres of longleaf (Pinus palustris Mill.) and loblolly (Pinus taeda L.) pine trees (10–11 years old, 147 ± 21.1 trees/acre; longleaf 52.14%, loblolly 47.86%). Site 2 comprised of 14 acres of 17–18 years old loblolly pine silvopastures. Both sites were planted with cool- and warm-season forages, and plots were rotationally grazed with goats (Site 1—Kiko wethers; Site 2— mixed breed of goats) during the 2015–2016 grazing seasons. Goat performance (live weight, body condition score, and FAMACHA score) was monitored every 2 weeks in Site 1, and trees were inspected for possible damage in both sites. Goats performed better while grazing cool-season forages during the spring. In Site 1, goats debarked pine trees, especially longleaf pines during the cool-season grazing period. No debarking was observed in Site 2. This study showed that southern pine silvopastures could provide a good grazing opportunity, but trees can be vulnerable to goats even when they are 10–11 years of age.

Title:

A Gingrich-style stocking chart for longleaf pine (Pinus palustris Mill.) forests

Author:

Kara, F.

Loewenstein, E. F.

Lhotka, J. M.

Kush, J. S.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Because of the dramatic decline in longleaf pine (Pinus palustris Mill.) acreage, concern about restoration and management of these ecosystems has increased in recent years and created a need for effective silvicultural management tools. Stocking charts are useful quantitative tools to allocate tree area to meet specific silvicultural objectives including restoration; however, there has not been one created specifically for longleaf pine forests. Because successful management of longleaf pine is often associated with density management at or near the onset of full site occupancy, which is readily determined on a stocking chart, the development of the chart for the species was needed. We developed a Gingrich-style stocking chart for longleaf pine forests using published approaches and models from the literature. Average maximum density (A-line stocking) was determined using forest inventory data whereas onset of full site occupancy (B-line stocking) was derived from an existing open-growth crown width equation. Reduced major axis regression was used to determine size-density relationships because it gives less biased and more efficient estimates than ordinary least squares regression. Previous studies, physiological data, and longleaf pine silvical traits all support the size-density characteristics depicted on this stocking chart. We found that percent stocking was better than basal area as a predictor of tree growth, although the difference between the two measures was not significant in understocked stands. The difference between percent stocking and stand density index as a predictor of tree growth was not statistically significant. With the stocking chart presented in this article, tree area relationships can be effectively and easily used to achieve specific silvicultural objectives.

Title:

Author:

Kara, F.

Loewenstein, E. F.

Brockway, D. G.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Aim of study: Uneven-aged (UEA) management systems can achieve multiple-use objectives, however, use of UEA techniques to manage longleaf pine (Pinus palustris Mill.) forests are still open to question, because of the species’ intolerance of competition. It was our aim to examine the influence of different levels (9.2, 13.8 and 18.4 m2 ha-1) of residual basal area (RBA) on longleaf pine seedling survival and growth following three growing seasons. Area of study: This study was conducted at the Escambia Experimental Forest, located on the Southern Coastal Plain of Alabama, in the southeastern United States. Material and Methods: Selection silviculture was implemented with the Proportional-Basal Area (Pro-B) method. Prescribed burning was conducted before seed dispersal and in the second year after germination. Photosynthetically active radiation (PAR) was measured under the canopy in the study plots. Survival and growth of longleaf pine seedlings were observed for three growing seasons. Main results: An inverse relationship was found between the number of germinants and RBA, but the mortality of germinants and planted seedlings was not affected by RBA. At age three, an inverse relationship was observed between root-collar diameter (RCD) growth of the germinants and RBA, but RCD growth of planted seedlings was not affected by RBA. Most of the study plots contained more than the projected number of seedlings needed to sustain the target diameter structure. Research highlights: Long-term continuous monitoring of seedling development and recruitment into canopy is required to determine the efficacy of UEA management. However, current data suggest that UEA methods may be a viable alternative to the use of even-aged (EA) methods in longleaf ecosystems.

Title:

Environmental factors affecting brown-spot infection on longleaf pine

Author:

Kais, A. G.

Year published:

1975

Publication Type:

Peer-reviewed literature

Abstract:

Indirect evidence suggested that light enhances infection of Pinus palustris by stimulating the opening of stomata through which the brown-spot fungus Scirrhia acicola penetrates the needles. In the absence of light, the fungus functions primarily as a wound parasite. Exposure of seedlings to high humidity both before and after inoculation shortened the incubation period and greatly increased the degree of infection. Delaying the high-humidity treatment of inoculated seedlings did not decrease infection. Although infection occurred over a wide range of temperature, a regimen of 35 C day and 27 C night was inhibitory. Maximum infection occurred under a 30 C day and a 21 C night. An efficient inoculation procedure is proposed for brown-spot studies.

Title:

Invasibility of a fire-maintained savanna-wetland gradient by non-native, woody plant species

Author:

Just, M. G.

Hohmann, M. G.

Hoffmann, W. A.

Year published:

2017

Publication Type:

None

Abstract:

Fire-promoting, open-canopy ecosystems are under threat of conversion to a fire-deterring, closed-canopy condition due to woody encroachment. This conversion of vegetation structure has been fostered by introduced woody plant species. We performed a field experiment to quantify growth, survival, and establishment success of six invasive, woody species along a managed longleaf pine savanna–wetland gradient in the Sandhills of North Carolina, USA. We investigated the effects of prescribed fire, fire history, dispersal, and abiotic conditions on the invasibility of sites along the gradient. Across 18 study sites, seeds of the six woody species were sown using three sowing methods that mimicked primary and secondary dispersal; each site contained paired plots located in savanna and savanna-wetland ecotone vegetation communities. We identified sowing treatment, abiotic conditions, seedling size, and prescribed fire as important factors for controlling woody invasion, as they prevented 5 of 6 study species from establishing in the landscape. However, the landscape was not immune to invasion. At the end of the 42-month study period, three species had established in unburned sites. In sites burned after seedling emergence, only one species, Pyrus calleryana, survived and established. We found P. calleryana survival and establishment to be a function of seedling size, soil humic matter content, and sowing treatment. Successful invasion and establishment of woody individuals in open-canopied systems increases the likelihood of fire-deterrence and further woody encroachment, threatening ecosystem integrity.2017

Title:

Where fire stops: vegetation structure and microclimate influence fire spread along an ecotonal gradient

Author:

Just, M. G.

Hohmann, M. G.

Hoffmann, W. A.

Year published:

2016

Publication Type:

Peer-reviewed literature

Abstract:

Positive feedbacks influenced by direct and indirect interactions between fire, vegetation, and microclimate can allow pyrophilic and pyrophobic ecosystems to co-occur in the same landscape, result ing in the juxtaposition of flammable and non flammable vegetation. To quantify the drivers of these feedbacks, we combined measurements of vegetation, fuels, and microclimate with observations of fire spread along ecotonal gradients. We established 113 permanent transects (consisting of 532 plots), each traversing an ecotone between savanna and wetland in the Sandhills of North Carolina, USA. In each plot, we recorded cover of ten plant functional types. We collected surface fuels at a subset of our transects. We continuously monitored microclimate (nine meteoro logical variables) across 21 representative ecotones. Following prescribed fire, we measured fire spread along each transect. Vegetation structure and micro climate significantly predicted fire spread along the savanna-wetland ecotone. Fire spread was most influ enced by vegetation structure, specifically C4 grass cover, which accounted for 67 % of the variance explained by our model. We have identified the components of the fire, vegetation, and microclimate feedback that control where fires stop under current conditions, but their control should not be considered absolute. For example, when ignited in savanna, prescribed burns continued through wetland vegeta tion 43 % of the time. The feedback operating within these systems may be relatively weak as compared to other savanna systems. Environmental changes may alter fire spread extent, and with it ecosystem bound aries, or even ecosystem states

Title:

Habitat associations of gopher tortoise burrows on industrial timberlands

Author:

Jones, J. C.

Dorr, B. S.

Year published:

2004

Publication Type:

Peer-reviewed literature

Abstract:

The western population of the gopher tortoise (Gopherus polyphemus) was listed as threatened under the Endangered Species Act in 1987 due to extensive population declines. Declines have been linked to site conversion of native pine (Pinus spp.) forests for urban development, agriculture, and commercial forest management. We conducted surveys to detect tortoise burrows on corporate timberlands in southern Mississippi and southwestern Alabama during summer 1994. We surveyed 2,759 0.5-ha strip transects on soil types of 9 different suitability categories for gopher tortoises. We found 460 active and 264 abandoned burrows on the 1,380 ha surveyed. Edaphic and vegetative conditions, such as sandy soils and total and midstory canopy coverage, influenced gopher tortoise occurrence. Logistic regression analyses revealed that active burrow occurrence was related positively to deep, sandy soils and related negatively to total canopy closure and fine loam soils with limited sand content. Abandoned burrow occurrence was related positively to increasing midstory canopy closure and selected soil types. Sandy soils and open overstory canopy that created favorable burrowing, nesting, and foraging conditions were important influences in active burrow occurrence. Vegetation management techniques, such as prescribed fire, midstory control, and intermediate forest stand thinning, are recommended on gopher tortoise conservation areas and connective corridor habitats on commercial timberlands. We theorize that restoration of longleaf pine (P. palustris) forests on sandy ridges can produce desirable core habitats and dispersal corridors for gopher tortoises in landscapes dominated by intensively managed pine plantations.

Title:

Defining old-growth stand characteristics in fragmented natural landscapes: a case study of old-growth pine in Florida (USA) state parks

Author:

Johnson, E. D.

Spector, T.

Hiers, J. K.

Pearson, D.

Varner, J. M.

Bente, J.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Despite historically dominating many landscapes of the southeastern United States, oldgrowth stands of southern pine (Pinus palustris, P. elliottii var. densa, P. elliottii Engelm. var. elliottii, P. echinata, and P. taeda) are extremely rare and have high ecological value, but may be underrepresented and mischaracterized due to small fragment size and restrictive definitions. Such misunderstanding is a barrier to future old-growth management and conservation. To quantify, characterize, and conserve these remnants, we conducted inventories for five species of old-growth southern pines on 16 sites across ~44,110 forested ha managed by the Florida Park Service. We used characteristics of old-growth pines and forests from the literature to locate potential sites and assess status and threats. This inventory documented 4697.5 ha of old-growth southern pines in 16 parks throughout Florida. The median size stand we inventoried or included due to existing documentation is 121 ha, with stands as small as eight ha and as large as 2020 ha. Despite their small relative extent, these stands harbor rare, threatened, or endangered species and represent significant conservation areas in the region. A threat common to most of the old-growth stands in Florida State Parks is complications from reintroduction of prescribed fire following prolonged fire exclusion. Heavy fuel loading and invasion of off-site species has resulted in high post-fire mortality linked to both forest floor duff consumption and overstory crown consumption. Management measures are presented to improve conditions of old-growth southern pines in Florida State Parks, and have relevance to broader conservation efforts in the southeastern USA.

Title:

Fox squirrel response to firest restoration treatments in longleaf pine

Author:

Boone, W. W.

McCleery, R. A.

Reichert, B. E.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

Restoration of the longleaf pine (Pinus palustris; LLP) ecosystem and its associated fauna is a principal goal of many land-management agencies in the southeastern United States. Prescribed fire and herbicide application are 2 common methods of LLP restoration. We employed a multi-scale approach to investigate how occurrence of fox squirrels (Sciurus niger) was influenced by fire frequency and herbicide application in LLP communities of northern Florida. We sampled 9-point, 4-ha grids of camera traps with 106 grids in fire treatments, 23 herbicide treatment grids, and 27 control grids. We evaluated a priori models for occurrence of fox squirrels at point, 4-ha patch, and home-range scales, and the influence of fire and herbicides on vegetation structure. Fox squirrel occurrence was positively associated with densities of turkey oak (Quercus laevis) at the patch scale, which were significantly less abundant in herbicide-treated areas. Fox squirrel occurrence was negatively correlated with fire interval and positively correlated with oak densities at a localized point scale. Additionally, fox squirrel point occurrences declined over time since the last fire. Fire produced habitat more favorable for fox squirrels than did herbicide treatments.

Title:

Evaluation of sowing methods to determine the role of hypocotyl lift in longleaf pine seedling development

Author:

Bolner, N. G.

Jackson, D. P.

Olatinwo, R.

Barnett, J. P.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Sonderegger pine (Pinus x sondereggeri H.H. Chapm.) is a hybrid pine species of loblolly pine (Pinus taeda L.) and longleaf pine (Pinus palustris Mill.) that is culled when noticed during seedling processing and packing in the nursery. Early indication of the hybrid has been theorized as the absence of a seed wing stub or hypocotyl lift off of the growing medium surface, although neither of these theories has been proven. Two trials were conducted to determine the role of container cell color, growing medium depth in the cells, and the presence of a seed wing stub on longleaf pine hypocotyl lift. Seedlings grown in black container cells had increased hypocotyl lift and tendency for reductions in root-collar diameter growth regardless of seed wing stub presence. Genetic testing indicated that both wingless and winged seeds were true longleaf pine.

Title:

Control of invasive Japanses climbing fern (Lygodium japonicum) and response of native ground cover during restoration of a disturbed longleaf pine ecosystem

Author:

Bohn, K. K.

Minogue, P. J.

Pieterson, E. C.

Year published:

2011

Publication Type:

Peer-reviewed literature

Abstract:

Japanese climbing fern (Lygodium japonicum) is an invasive species prevalent through the southeastern United States that grows on, around, and intermingles with native groundcover in a variety of forest ecosystems. Management of this species can be problematic because herbicide control must also ensure minimal impact to native plants, particularly in ecosystems undergoing restoration and recovery from disturbance. We tested 3 herbicides (glyphosate, imazapyr, and metsulfuron methyl) at various rates, alone and in combination, to evaluate their efficacy for fern control and impacts to non-target, native groundcover in a longleaf pine (Pinus palustris) ecosystem subject to dormant season burns and hurricane and salvage logging disturbances. All herbicide treatments reduced Japanese climbing fern cover by 77–98% at 1 yr following treatment, but at 2 yr there was considerable re-growth on imazapyr and metsulfuron-methyl treated plots. Glyphosate applied alone as a 2 or 4% solution provided 91–98% fern control after 2 yr, and there was no significant improvement using combinations of glyphosate with other herbicides. Climbing fern cover increased by 70% in the untreated control. We found a significant correlation between reduction in fern cover and increase in other vegetation, though species composition changed minimally. Species richness at 2 yr after treatment increased by 2–3 species following application of glyphosate alone or in combination, and decreased on the untreated control. We recommend directed spray applications using 2% glyphosate solutions for efficient control. Using this approach on matted fern should result in little detriment to native groundcover, even with this broad-spectrum herbicide.

Title:

Infulence of selection method on skidder-trail soil compaction in longleaf pine forest

Author:

Bigelow, S. W.

Jansen, N. A.

Jack, S. B.

Staudhammer, C. L.

Year published:

2018

Publication Type:

Peer-reviewed literature

Abstract:

Silvicultural selection systems present trade-offs between concentrating soil impacts in small areas and dispersing them across a stand. We applied three selection methods in longleaf pine forest on coarse-textured soils: single-tree, group (ca. 0.2 ha opening size), and group with reserved trees. Area disturbed was determined from GPS units on skidders, soil compaction was inferred from bulk density and penetration resistance, and tree growth was measured on longleaf seedlings planted in skidder trails. Skidder trails covered an average 3.5 ± 1.5% (sd) of stand area. Under single-tree selection, more area was affected by single passes than higher numbers of passes, but under group and group with reserves selection more area was affected by higher numbers of passes. Bulk density and penetration resistance went up rapidly as number of skidder passes increased, as did seedling growth. Of concern was that penetration resistance at 20–30 cm depth exceeded theoretical thresholds for root growth after 15 passes. Overall, somewhat more compaction occurred under group methods than the single-tree method. Despite absence of predicted compaction impacts on early longleaf pine growth, foresters should stay alert to the possibility of later productivity declines in heavily used skid trails due to subsurface soil compaction and consolidation

Title:

Longleaf pine proximity effects on air temperatures and hardwood top-kill from prescribed fire

Author:

Bigelow, S. W.

Whelan, A. W.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Regulation of the dominance of resprouting understory hardwoods is a common objective for prescribed fire in open-canopy longleaf pine (Pinus palustris Mill.) woodland of the southeastern USA. Nevertheless, little is known about the influence of individual pines on fire and hardwood mortality. We studied growing-season fires in stem-mapped stands in southwest Georgia, USA; the stands displayed large variation in structure due to cutting treatments applied seven years earlier. We measured air temperature and heating duration, and measured post-fire sprouting behavior of four guilds of understory hardwoods: mesic oaks (Quercus spp. L.), upland oaks, xeric oaks, and fleshy-fruited hardwoods. Mean air temperature (i.e., of flames, buoyant plume, and smoldering combustion) and heating duration (time over 60 °C) were analyzed with respect to fuel-bed conditions and neighboring tree density. Hardwood top-kill was analyzed with respect to neighboring tree density and hardwood height. The basal area of nearby pines strongly affected heating duration (time over 60 °C), which increased linearly from a mean of 87 s to a mean of 234 s across a gradient of pine basal area from 0 to 30 m2 ha−1. Mean air temperature during prescribed fire was unaffected by pine density but increased linearly from a mean of 114 °C to a mean of 148 °C across a gradient of wiregrass (Aristida stricta Michx.) cover from 0 to 100%, respectively. Neighborhood models showed that time over 60 °C during the burns was longest at the base of pines and decreased by two thirds at 3.3 m distance. Pines affected hardwood top-kill probability at a similar scale, the effect at 4.4 m decreasing by two thirds compared to at the base of the pine. The four hardwood guilds were readily top-killed when ≤1 m tall, but at 2 m height, upland and xeric oaks had become more resistant to top-kill than mesic oaks or fleshy-fruited hardwoods. The influence of individual pine trees on heating duration and top-kill power of prescribed fire drops by two thirds of maximum within 3 to 4 m of a tree, compared to a maximum at the base of the tree. Neighborhood models provide a method to estimate tree effects on prescribed fire heating duration and top-kill probability, and thus a way of predicting stand structures that provide ecological benefits of openings while remaining below thresholds that trigger vigorous hardwood response.

Title:

A systems model approach to determining resilience surrogates for case studies

Author:

Bennett, E. M.

Cumming, G. S.

Peterson, G. D.

Year published:

2005

Publication Type:

Peer-reviewed literature

Abstract:

Resilience theory offers a framework for understanding the dynamics of complex systems. However, operationalizing resilience theory to develop and test empirical hypotheses can be difficult. We present a method in which simple systems models are used as a framework to identify resilience surrogates for case studies. The process of constructing a systems model for a particular case offers a path for identifying important variables related to system resilience, including the slowly-changing variables and thresholds that often are keys to understanding the resilience of a system. We develop a four-step process for identifying resilience surrogates through development of systems models. Because systems model development is often a difficult step, we summarize four basic existing systems models and give examples of how each may be used to identify resilience surrogates. The construction and analysis of simple systems models provides a useful basis for guiding and directing the selection of surrogate variables that will offer appropriate empirical measures of resilience.

Title:

Landscape-scale restoration of the longleafpPine ecosystem

Author:

Johnson, R.

Gjerstad, D.

Year published:

1998

Publication Type:

Peer-reviewed literature

Title:

Forest vegetation and vascular flora of Reed Brake Research Natural Area, Alabama

Author:

Beckett, S.

Golden, M. S.

Year published:

1982

Publication Type:

Peer-reviewed literature

Abstract:

Eight forest community types are defined and described for Reed Brake Research Natural Area, a 242 ha tract in the Hilly Coastal Plain of central Alabama. Community locations are related to topographic position, past logging history, slope direction, and slope steepness. The community types are: Longleaf Pine, Shortleaf Pine-Hardwoods, Southern Red Oak-Mixed Oak, Chestnut Oak, Loblolly Pine-Upland Hardwoods, Loblolly Pine-Lowland Hardwoods, Sweetgum-Yellow-Poplar, and Swamp Tupelo-Sweetbay. Due to fire protection, hardwoods are increasing in importance in the Longleaf Pine communities. An annotated floristic list is presented, with 235 vascular plant taxa referable to 75 families and 153 genera.

Title:

The effect of spatially variable overstory on the understory light environment of an open-canopied longleaf pine forest

Author:

Battaglia, M. A.

Mou, P.

Palik, B. J.

Mitchell, R. J.

Year published:

2002

Publication Type:

Peer-reviewed literature

Abstract:

Spatial aggregation of forest structure strongly regulates understory light and its spatial variation in longleaf pine (Pinus palustris Mill.) forest ecosystems. Previous studies have demonstrated that light availability strongly influences longleaf pine seedling growth. In this study, the relationship between spatial structure of a longleaf pine forest and spatial pattern of understory light availability were investigated by comparing three retention harvest treatments: singe-tree, small-group, large-group, and an uncut control. The harvests retained similar residaul basal area but the spatial patterns of the residual trees differed. Hemispherical photographs were taken at 300 stations to calculate gap light index (GLI), an estimate of understory light availability. Stand-level mean, variation, and spatial distribution of GLI were determined for each treatment. By aggregating residual trees, stand mean GLI increased by 20%, as well as its spatial variation. Spatial autocorrelation of GLI increased as the size of the canopy gaps increased and the gaps were better defined; thus, the predictability of GLI was enhanced. The ranges of detrended semivariograms were increased from the control to the large-group harvest indicating the spatial patterns of understory GLI became coarser textured. Our results demonstrated that aggregated canopy structure of longleaf pine forest will facilitate longleaf pine seedling regeneration.

Title:

An annoted checklist of bees (Hymenoptera: Apoidea) in longleaf pine savannas of souther Louisiana and Mississippi

Author:

Bartholomew, C. S.

Prowell, D.

Griswold, T.

Year published:

2006

Publication Type:

Peer-reviewed literature

Abstract:

We cataloged the bee fauna to determine potential pollinators in upland and wet longleaf pine savannas in Louisiana. A total of 122 species of bees were collected from four savanna sites. A regional list of 165 species was produced by adding species collected from nearby savannas in Mississippi. Our Louisiana survey documented range extensions for 23 species, 64 new state records, and two possible new species. Upland savannas contained a higher proportion of range restricted bees. Three species collected at upland sites are typically associated with prairies or grasslands and are potential targets for conservation efforts. Biogeographically, the fauna is eastern or southeaster with 68% of the species ranges extending eastward. Species composition comparisons of the Louisiana savanna fauna with other grassland and sand scrub habitats indicated 45% overlap with Mississippi, 30% with southern Florida, 29% with Indiana/Illinois, and 22% with Minnesota. Based on our Louisiana study and one nearby in Mississippi, longleaf pine savannas on the western edge of East Gulf Coastal Plain are likely to contain close to 200 species of bees.

Title:

A review of chemical treatments to improve germination of longleaf pine seeds

Author:

Barnett, J. P.

Varela, S.

Year published:

2004

Publication Type:

Peer-reviewed literature

Abstract:

Nursery managers can improve germination of longleaf pine (Pinus palustris P. Mill. [Pinaceae]) seeds and seedling establishment by reducing seedborne pathogenic fungi with appropriate sterilants and fungicides. We have tested many chemicals, but hydrogen peroxide, thiophanate methyl, and thiram seem to provide the best results in reducing the large populations of microorganisms carried on the large, thin, and fibrous seed coats. Our evaluations of longleaf seeds indicate that Fusarium spp. are major seedborne pathogens that cause mortality to seeds and newly germinated seedlings. Seeds of other southern pines have denser coats and are less adversely affected by the presence of seedborne pathogens. The increased demand for longleaf pine seeds in the last few years makes reducing this contamination an important consideration by seed dealers and nursery managers.

Title:

Longleaf pine ecosystem restoration: the role of fire

Author:

Barnett, J. P.

Year published:

1999

Publication Type:

Peer-reviewed literature

Abstract:

Longleaf pine (Pinus palustris Mill.) ecosystems once occupied over 36 million hectares in the southeastern United States’ lower coastal plain. These fire-dependent ecosystems dominated a wide range of coastal plain sites, including dry uplands and low, wet flatlands. Today, less than 1.3 million hectares remain, but these ecosystems represent significant components of the Region’s cultural heritage, ecological diversity, timber resources, and present essential habitat for many animal and plant communities. Fire was an essential component of the original longleaf pine ecosystems. The landscapes were characterized by open stands of mature iongleaf pine with a savanna-like understory that were biologically diverse. Recent improvements in the technology to artificially regenerate longleaf pine has stimulated interest in restoring longleaf pine on many sites. Long-term studies show that the frequent use of fire hastens initiation of height growth, reduces undesirable competing vegetation, and stimulates growth and development of the rich undcrstory. So,fire is an important element in establishing the species and is critical toachieve and maintain the biologically diverse understory that is characteristic of the ecosystem

Title:

Sixty years of management on a small longleaf pine forest

Author:

Barlow, R.

Kush, J. S.

Boyer, W. D.

Year published:

2011

Publication Type:

Peer-reviewed literature

Abstract:

In 1948, the US Forest Service set aside a 40-ac tract on the Escambia Experimental Forest in South Alabama to demonstrate longleaf pine (Pinus palustris Mill.) management for the small landowner. At that time, the management goal for this “Farm 40” was to produce high-quality poles and logs on a 60-year rotation. The goal was to be accomplished entirely through management of the existing natural forest, with little to no capital investment other than the cost for prescribed burning, marking trees for cut, and limited control of cull hardwoods. Management of the forest has continued making the Farm 40 an excellent demonstration of small-scale longleaf pine management. Frequent harvests and small capital outlay continues to make this type of management strategy especially appealing to today’s landowners with limited resources.

Title:

Agricultural land-use history does not reduce woodland understory herb establishment

Author:

Barker, C. A.

Turley, N. E.

Orrock, J. L.

Ledvina, J. A.

Brudvig, L. A.

Year published:

2019

Publication Type:

Peer-reviewed literature

Abstract:

Agricultural land use is a leading cause of habitat degradation, leaving a legacy of ecological impacts long after agriculture has ceased. Yet the mechanisms for legacy effects, such as altered plant community composition, are not well understood. In particular, whether plant community recovery is limited by an inability of populations to establish within post-agricultural areas, owing to altered environmental conditions within these areas, remains poorly known. We evaluated this hypothesis of post-agricultural establishment limitation through a field experiment within longleaf pine woodlands in South Carolina (USA) and a greenhouse experiment using field-collected soils from these sites. In the field, we sowed seeds of 12 understory plant species associated with remnants (no known history of agriculture) into 27 paired remnant and post-agricultural woodlands. We found that post-agricultural woodlands supported higher establishment, resulting in greater species richness of sown species. These results were context dependent, however, with higher establishment in post-agricultural woodlands only when sites were frequently burned, had less leaf litter, or had less sandy soils. In the greenhouse, we found that agricultural history had no impact on plant growth or survival, suggesting that establishment limitation is unlikely driven by differences in soils associated with agricultural history when environmental conditions are not stressful. Rather, the potential for establishment in post-agricultural habitats can be higher than in remnant habitats, with the strength of this effect determined by fire frequency and soil characteristics.

Title:

Evaluating the relationship between vegetative composition and forest aesthetics of prescribed fire management in longleaf pine (Pinus palustris Mill.) forests

Author:

Atasoy, M.

Barlow, R. J.

Kush, J. S.

Year published:

2017

Publication Type:

Peer-reviewed literature

Abstract:

The majority of the coastal plain from Virginia to Texas was predominantly covered by longleaf pine (Pinus palustris Mill.) stands. These forests were described as 'park like' forests with a clean, aesthetic, and picturesque understory. However, European settlement dramatically degraded the longleaf pine ecosystem. Today, suppression of fires has substantially reduced the pine reproduction, increased the woody understory vegetation, and has significantly decreased the stand maintenance and regeneration of longleaf pine stands. Yet, there is a gap in understanding the relationship between the scenic beauty, forests aesthetics and how prescribed fire treatments impact the public perception of longleaf pine forests. This study aims to evaluate how different seasons and timing of prescribed fire treatments impact the scenic beauty of longleaf pine forests on the Escambia Experimental Forest near Brewton, Alabama. The main objectives of this research was to examine the forest measurements associated with each of the prescribed fire treatments in an attempt determine additional factors that may contribute to the scenic beauty of a forest scene.

Title:

The initial phase of a longleaf pine-wiregrass savanna restoration: species establishment and community responses

Author:

Aschenbach, T. A.

Foster, B. L.

Imm, D. W.

Year published:

2010

Publication Type:

Peer-reviewed literature

Abstract:

The significant loss of the longleaf pine‐wiregrass ecosystem in the southeastern United States has serious implications for biodiversity and ecosystem functioning. In response to this loss, we have initiated a long‐term and landscape‐scale restoration experiment at the 80,125 ha (310 mi2) Department of Energy Savannah River Site (SRS) located near Aiken, South Carolina. Aristida beyrichiana (wiregrass), an important and dominant grass (i.e., a “matrix” species) of the longleaf pine savanna understory, and 31 other herbaceous “non‐matrix” species were planted at six locations throughout SRS in 2002 and 2003. Of the 36,056 transplanted seedlings, 75% were still alive in June 2004, while mean 1–2 year survival across all planted species was 48%. Lespedeza hirta (hairy lespedeza) exhibited the greatest overall survival per 3 × 3 m cell at 95%, whereas Schizachyrium spp. (little bluestem) exhibited the greatest mean cover among individual species at 5.9%. Wiregrass survival and cover were significantly reduced when planted with non‐matrix species. Aggregate cover of all planted species in restored cells averaged 25.9% in 2006. High rates of survival and growth of the planted species resulted in greater species richness (SR), diversity, and vegetative cover in restored cells. Results suggest that the loss of the longleaf pine‐wiregrass ecosystem may be ameliorated through restoration efforts and illustrate the positive