To improve habitat quality for wildlife, habitat managers prescribe various disturbances. Habitat management techniques alter the vegetation structure, composition, and quality, changing food and cover resources and availability. To investigate how habitat management and vegetation heterogeneity affect space use by wildlife species, I deployed 81 camera-traps and collected fine scale vegetation data across a variety of treatments (i.e., canopy reduction, prescribed fire, and herbicide application) in a managed loblolly pine forest. I created a new method for accounting for imperfect detection and error in camera count data. My method provided better inference about the effects of variables on animal use. Species responded differently to different functional groups of plants, but predicted use from generalized additive models showed higher use in the most intensively managed pine stands, indicating that management promotes animal use by improving habitat quality. Animals used every treatment, indicating the need for heterogeneity in resources when managing wildlife.

The Bachman’s sparrow (Peucaea aestivalis) is a ground-dwelling, pine-obligate species experiencing range-wide population declines due to land development and fire exclusion. We explored the effects of fire seasonality on wintering Bachman’s sparrow abundance in Southern Mississippi from 2021-2022. We used generalized linear mixed models to investigate differences in sparrow abundance and vegetation characteristics following dormant and growing season fire. We explored the effects of growing season fire on breeding territory vegetation characteristics. Our results indicate that burn type (dormant vs. growing season), native grass groundcover, and shrubs over 1m were the most significant predictors for wintering Bachman’s sparrow abundance. Additionally, native grass groundcover increased in growing season breeding territories post-fire while grass standing crop and shrubs over 1m decreased. We recommend a combination of dormant and growing season fire when feasible to promote a matrix of conditions suitable for Bachman’s sparrows throughout their life cycle in the Southeastern United States.

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Despite the prevalent distribution of bobcats in western Virginia and the broader region of Appalachia, there is a paucity of information on their spatial ecology in this region. Due to the unique ecological conditions of Appalachia, and increasing public interest surrounding the role of bobcats as predators in the region, there is a need for local information on bobcat ecology. I utilized data from 20 GPS collared bobcats (14M, 6F) to investigate bobcat spatial ecology in the mountains of Western Virginia. Average resident male home range size was 33.9 ± 2.6 km^2, nearly 3 times larger than average resident female home range size (12.1 ± 2.4 km^2). Seasonal areas of use did not differ in size among seasons, but exhibited minor shifts in location and shape. Average male movement rates (232.3 ± 12.0 meters/hour) were 1.5 times greater than average female movement rates (154.4 ± 8.9 meters/hour). Male movement rates increased during the dispersal season and female movement rates increased during the denning/kitten-rearing season. Second order resource selection analysis indicates that bobcats of both sexes select home ranges at higher elevations than expected at random, and that selection varies between sexes and among seasons. Third order resource selection analysis indicates that bobcats select for locations near open canopy structure, and avoid forest interior. These findings build upon previous findings regarding bobcat diet and population dynamics to provide a comprehensive understanding of basic bobcat ecology in western Virginia, and will inform further research investigating predator/prey interactions. / Master of Science / Despite the prevalent distribution of bobcats in western Virginia and the broader region of Appalachia, there is a paucity of information on their spatial ecology in this region. Due to the unique ecological conditions of Appalachia, and increasing public interest surrounding the role of bobcats as predators in the region, there is a need for local information on bobcat ecology. I utilized data from 20 GPS collared bobcats (14M, 6F) to investigate bobcat spatial ecology in the mountains of Western Virginia. I found that male bobcats use more space than females, with home ranges nearly 3 times larger and movement rates 1.5 times higher. I found that home ranges do not expand or contract throughout the year, but do shift in shape slightly. I found that bobcats select home ranges at higher elevations, indicating that home ranges are predominantly located on ridges. I found that selection of home ranges differed between sexes and seasons, indicating that shifts in home range shape throughout the year reflect varying habitat selection. Within their home ranges, I found that bobcats select for areas of open canopy resulting from fields, fire, and timber harvest; and avoid areas of forest interior. These findings build upon previous findings regarding bobcat diet and population dynamics to provide a comprehensive understanding of basic bobcat ecology in western Virginia, and will inform further research investigating predator/prey interactions.

Prescribed fire use in Virginia and West Virginia has increased over the past ten years as forest managers on public lands have increasingly used prescribed fire to meet management goals. These goals include hazardous fuel reduction, wildlife habitat restoration and management, and control of less desired vegetation. Research is needed to better understand the effects of wildland fire on forest ecosystems. In this study, we addressed wildland fire's effects on water, vegetation, and soil resources in the central Appalachian Region. Moreover, the long-term efficacy of various types of timber harvests on forest fuel reduction was analyzed. Over fifty peer-reviewed articles were evaluated to characterize the effects of prescribed fire on physical, chemical, and biological water quality parameters throughout the eastern United States. It was determined that fires of low to moderate intensity and severity may cause short-term sediment and nutrient increases in nearby waterbodies, but these effects often dissipate within 2-3 years. Effects on biological organisms are more transient, frequently lasting from a few weeks to a few months. Regeneration following wildfires at three sites in Virginia and West Virginia varied due to fire behavior and time since fire. Preferred and undesired species responded differently at each site. Follow-up treatments and continued monitoring are needed to obtain desired vegetative compositions post-fire. Two dormant season prescribed fires on the Fishburn Forest near Blacksburg, Virginia were studied for mineral soil chemistry effects. Both treatment and time affected macronutrient levels, but no differences were present 6 and 14 months post-fire between burned and unburned locations. Forest fuels were quantified approximately 20 years following different silvicultural harvests on the George Washington-Jefferson National Forest. Fuels of different size classes responded differently to different harvests as fine fuels were reduced by the high-leave shelterwood treatment, and coarse woody fuels were reduced by the clearcut and low-leave shelterwood treatments. Overall, low intensity and low severity fires induce minimal, potentially negative changes in water and soil quality. In contrast, wildfires of high intensity and severity may potentially contribute to changes in species composition and forest floor properties. Furthermore, varying levels of overstory removal may reduce extreme wildfire risk for decades. The findings of this study reinforce the need for continued research and monitoring of both wildfire effects and prescribed fire use in the central Appalachian Region. / Doctor of Philosophy / It is well-documented that fire has occurred in forested ecosystems for millennia. In addition to natural ignitions, indigenous peoples used fire for various reasons, such as understory reduction, hunting, and crop cultivation. As European settlers arrived and advanced across North America, they continued to use fire as a tool to shape the landscape to fit their societal needs. The use of fire by humans in North America all but ceased in the early 20th century. Large fire events in the western United States motivated the newly created United States Forest Service to restrict fire from the landscape. The fire exclusion policy of the early 20th century had unintended consequences, such as increased fire risk due to fuel accumulation and a shift from fire-tolerant species, such as oaks and pines, to fire-intolerant species. More recently, the perception of wildland fire has been re-examined due to ecological and societal issues. Although federal and state agencies are burning more acres, the public's wariness towards wildland fire is prevalent. As attitudes about wildland fire have changed, so have the research needs. Information regarding the effects of both wild and prescribed fires on forest ecosystems is needed throughout the United States, including the eastern United States, and more specifically, within the central and southern Appalachian Mountains. This dissertation discusses the effects of both wild and prescribed fires on various forests processes within these regions. In this dissertation, 1) the impacts of prescribed fire on water quality, 2) the responses of forest vegetation to wildfire, and 3) and the effects of prescribed fire on soil nutrients were investigated. Additionally, different timber harvests were studied to determine their long-term effects on potentially hazardous fuel loads. The results indicated that water quality is generally not impacted by low intensity and severity prescribed fires in the eastern United States. It was determined that vegetation often responds vigorously to wildfires, and subsequent species composition varies based on factors such as fire severity, site conditions, time since fire, and overstory species composition. When examining soil nutrients for 14 months following prescribed fires, nutrient changes occurred in both unburned and burned locations. When fuel loads were compared between timber harvests of varying intensities, woody fuels were reduced in the long-term. This reduction may minimize potential wildfire behavior and effects. While both wild and prescribed fires impact forest processes, they generally do so in different ways. This is mainly due to differences in fire behavior between these fire types. Effects of wildfires on water quality, soil chemistry, and vegetation tend to last longer than prescribed fire. Additionally, prescribed fire, when used in conjunction with other forest management activities, may reduce potentially negative wildfire impacts. Monitoring post-fire effects is critical to understanding the best way to use prescribed fire as a forest management tool.

Lygodium microphyllum, native to the Old World tropics, has invaded central and southern Florida, destroying native habitats, reducing biodiversity and altering fire regimes. Prescribed fire, one of several methods used to manage L. microphyllum infestations, reduces fern biomass over large areas, but its effects on spore viability are unknown. To provide tools to evaluate whether fire-dispersed spores are viable, this research determined how heat affects spore viability. Spores were exposed to temperatures of 50°C to 300°C for durations of 5 seconds to 1 hour, then allowed to germinate on agar in petri plates. Percent germination was assayed after two weeks. Temperatures of 50°C had little effect; 300°C killed spores for all durations. Results indicate that while viability of unburnt spores decreases with increasing temperature and duration of heat exposure, spores are killed when exposed to relatively low temperatures compared to those in fires.

Land managers need to rapidly assess vegetation composition and bare ground to effectively evaluate, manage, and restore shrub steppe communities that have been encroached by pinyon and juniper (P-J) trees. A major part of this process is assessing where to apply mechanical and prescribed fire treatments to reduce fuel loads and maintain or restore sagebrush steppe rangelands. Geospatial technologies, particularly remote sensing, offers an efficient option to assess rangelands across multiple spatial scales while reducing the need for ground-based sampling measurements. High-spatial resolution color-infrared imagery (0.06-m pixels) was acquired for sagebrush steppe communities invaded by P-J trees at five sites in Oregon, California, Nevada, and Utah with a Vexcel Ultra CamX digital camera in June/July 2009. In addition to untreated P-J woodlands, imagery was acquired over P-J woodlands where fuels were reduced by either prescribed fire, tree cutting, or mastication treatments. Ground measurements were simultaneously collected at each site in 2009 on 0.1-hectare subplots as part of the Sagebrush Steppe Treatment Evaluation Project (SageSTEP). We used Trimble eCognition Developer to 1) develop efficient methods to estimate land cover classes found in P-J woodlands; 2) determine the relationship between ground measurements and object-based image analysis (OBIA) land cover measurements for the following classes: trees (live, burned, cut, and masticated), shrubs, perennial herbaceous vegetation, litter (including annual species), and bare ground; and 3) evaluate eCognition rule-sets (models) across four spatial scales (subplot, site, region, and network) using untreated P-J woodland imagery. At the site scale, the overall accuracy of our thematic maps for untreated P-J woodlands was 84% with a kappa statistic of 0.80. For treatments, the overall accuracy and kappa statistic for prescribed fire was 85% and 0.81; cut and fell 82% and 0.77, and mastication 84% and 0.80, respectively, each indicating strong agreement between OBIA classification and ground measured data. Differences between mean cover estimates using OBIA and ground-measurements were not consistently higher or lower for any land cover class and when evaluated for individual sites, were within 5% of each other; all regional and network OBIA mean cover estimates were within 10% of the ground measurements. The trade-off for decreased precision over a larger area (region and network scale) may be useful to prioritize fuel-management strategies but will unlikely capture subtle shifts in understory plant communities that site and subplot spatial scales often capture. Although cover assessments from OBIA differed somewhat from ground measurements, they were accurate enough for many landscape-assessment applications such as evaluating treatment success and assessing the spatial distribution of fuels following fuel-reduction treatments on a site scale.

Following wildfires, plant materials are direct-seeded to limit erosion and annual weed invasion. Seedlings often fail to establish because selected plant materials are not always well adapted to local soil moisture and temperature conditions. In an effort to help improve plant materials selection and to evaluate sites potential revegetation, we have worked toward developing methodology to predict germination and root growth based on site specific soil moisture and temperature conditions. First, we characterized the seedbed environment of 24 sagebrush (Artemisia spp.) steppe sites throughout the Intermountain West to determine the wet-thermal time of five temperature ranges relevant to germination response and thermal-time model accuracy (Chapter 1). Second, we predicted potential germination for 31 plant materials at those same sites (Chapter 2). Third, in preparation to predict root growth at multiple sites, we characterized the drying patterns and the associated plant-available water for in the seedling root zone across nine woodland (Juniperus spp. and Piñus spp.) sites (Chapter 3). For all of these studies, we determined the effects of tree reduction and tree infilling phase at time of tree reduction. Our key findings are that seedbeds generally sum most wet-thermal time at temperature ranges where the germination rates fit thermal accumulation models quite well (R2 ≥ 0.7). The majority of plant materials summed enough wet-thermal time for a potential germination at most sites during the fall, early spring, and late spring. Soil drying primarily occurs from the soil surface downward. Drying rates and Plant available water associated with the first drying event increased with increasing soil depth. Root zone (1-30 cm) plant-available water increased before and decreased after the first spring drying event with increasing soil depth. Tree removal with increasing pretreatment tree infilling phase generally added progress toward germination, plant available water, and wet-thermal time in the seedbed and root zones of the sagebrush steppe in the Great Basin. Because soil moisture and temperature does not appear to be limiting for potential germination, combining germination and root growth models to create a more comprehensive model may allow for a more robust prediction for seedling survival. For either root growth or combined germination and root growth models, plant available water and wet-thermal time before the first spring drying period hold the most potential for successfully predicting seedling survival.

Species-species and species-habitat interactions have been demonstrated to be important in influencing diversity across a variety of ecosystems. Despite generalities in the importance of these interactions, appropriate mechanisms to explain them are absent in many systems. In sandhill systems of the southeast U.S., gopher tortoises have been hypothesized to be a crucial species in the maintenance of diversity and function. However, the mechanisms and magnitude in which they influence their communities and habitats have rarely been empirically quantified. I examined how habitat structure influences tortoise abandonment of burrows and how tortoise densities influence nonvolant vertebrate community diversity. Tortoise burrow abandonment is directly influenced by canopy closure, with each percent increase in canopy cover relating to a ~2% increase in the probability of burrow abandonment. In addition, tortoise burrow density was positively correlated with diversity and evenness, but not species richness. This influence was directly proportional to burrow density, supporting a dominance role for this species and rejecting the commonly asserted keystone species mechanism. I also quantified the influence of tortoises in influencing diversity relative to other environmental and habitat variables. Through this research, I have demonstrated that disturbance and habitat structure are important, but diversity responds most to density of burrows in the habitat. These findings demonstrate the intricate relationships interacting to maintaining diversity in sandhill systems. In particular, habitat change leading to declines of gopher tortoises may have drastic negative impacts on vertebrate species diversity.

Prescribed fire is commonly used to manage white-tailed deer habitat. However, nutrition is still limited during the summer for deer in the Southeast and prescribed fire is commonly restricted to the dormant season. Knowledge of fire phenology effects on summer nutrient availability is relatively unknown. Stump sprouts may also affect available nutrition, which could be important when managing for summer nutrition. To address this summer nutritional stress period, I examined impacts prescribed fire phenology and mechanical stump sprouting had on summer nutritional carrying capacity for deer. Results indicated implementing prescribed fire in both dormant and growing-seasons led to increased summer nutrient availability on the landscape level by increasing forage quality and quantity. Mechanically creating stump sprouts from woody plants led to increased available nutrition on a localized level. Combining these management actions to target summer nutritional stress periods can better help deer meet nutritional demands and reach their full potential.