In forested ecosystems, salamanders occupy important ecological roles as predator, prey and as potential regulators of ecological processes. The effects of forest management, particularly clearcut harvesting, on salamanders have been well documented; removal of overstory trees negatively affects abundances of salamanders. However, the length of time that salamander populations remain depressed following forest harvesting and factors limiting population recovery have been a source of controversy in the literature and are the goal of this dissertation. As part of the Southern Appalachian Silviculture and Biodiversity (SASAB) project (Chapter 1), a long-term replicated field experiment designed to evaluate a range of silvicultural treatments on biodiversity, I evaluated specific hypotheses related to salamander populations, their prey, and their habitat. First, I examined long-term trends in salamander abundances across a range of silvicultural treatments to determine whether negative effects of forest harvesting persisted for 13-years after harvest (Chapter 2) and to document the effects of multiple harvests on salamanders (Chapter 3). The relative abundances of terrestrial salamanders were quantified in six silvicultural treatments and an unharvested control and on six replicated field sites with night-time, area-constrained searches. Across 13-years of post-harvest data, terrestrial salamander abundances generally were lower in silvicultural treatments with some disturbance to the canopy (group selection harvest through silvicultural clearcut). Further, a comparison of demography of common species of salamanders suggested that differences in habitat quality existed between harvested and unharvested experimental units (EUs). A second harvest in the shelterwood plots to remove overwood had a cumulative negative effect on salamanders at one of two sites studied. Additionally, I conducted a sensitivity and elasticity analysis for eastern red-backed salamanders (Plethodon cinereus) and modeled population growth to evaluate the contribution of demographic parameters to population recovery. These analyses indicated that adult survival was the parameter with the greatest influence on the population growth rate and that >60 years would be required for recovery of salamander populations to preharvest levels even if habitat conditions were restored to preharvest conditions immediately. Next, I quantified the bioenergetics of salamanders across a disturbance gradient to evaluate whether changes to (1) invertebrate prey, (2) energy expenditure for basic maintenance costs, and or (3) an index to body condition could help explain observed changes to abundances or demography of salamanders from forest harvesting (Chapter 4). Although I did not detect a difference in abundances of invertebrates along the disturbance gradient, I determined that salamanders in recently disturbed forest stands expended approximately 33% more energy for basic maintenance costs in an active season and the body condition of salamanders was greater at one of two sites in disturbed EUs. Thus, the bioenergetics of terrestrial salamanders may have been affected by increasing temperatures from silvicultural disturbance and may cause salamanders to allocate less energy to reproduction or growth because of increased maintenance costs. In collaboration with Eric Sucre, Department of Forestry at Virginia Tech, I examined the effects of salamanders on invertebrates and ecosystem processes, specifically leaf litter decomposition. We constructed 12 in situ field mesocosms and I manipulated densities of red-backed salamanders into zero, low, and high density treatments. From June 2006-June 2008, I estimated invertebrate abundances, rates of leaf litter decomposition and food habits of salamanders across treatments. I found that invertebrate abundances were more affected by season than by the density of salamanders and that rates of leaf litter decomposition did not differ among salamander treatments. Salamanders were euryphagic and consumed more (by abundance and volume) herbivorous invertebrates than predators or detritivores. Finally, I modeled habitat relationships of terrestrial salamanders at two spatial scales on the SASAB study sites (Chapter 6). I quantified abundance of salamanders with area-constrained searches during warm rainy nights and measured forest characteristics related to foraging or refugia habitats or that described the overstory and understory of forest stands. At the scale of the 30 m2 transect and the 10 m2 sub-transect, abundance of salamanders was best described by models that incorporated descriptors of canopy cover and woody and herbaceous understory vegetation. Thus, terrestrial salamanders may have responded positively to forest stands with a mature overstory and structurally diverse understory for foraging habitat. Collectively, these data suggest that recovery of salamander populations after forest harvesting will take approximately 60 years, and that life history characteristics (low fecundity, late sexual maturity) and possibly changes to bioenergetics may contribute to the slow recovery. Further, silvicultural practices that retain some canopy trees through a rotation may have a more rapid return of salamander populations to preharvest levels and may encourage development of understory structure for salamander foraging. Although these data fill some gaps in knowledge of relationships between silviculture and terrestrial salamanders, many questions about long-term effects of disturbances on populations and habitats remain. My modeling of recovery of salamander populations depended on estimates of a survival from a congener, and I did not document whether forest harvesting decreases survival of terrestrial salamanders. Lastly, the influence of stochastic events on population dynamics particularly in disturbed stands was not examined in this dissertation. Therefore, future research on the SASAB study sites should continue to track abundances and demography across the disturbance gradient, acquire age-specific estimates of survival, determine whether salamanders exhibit density dependence, develop estimates of entire energy budgets, and use manipulative laboratory experiments to describe the role of plethodontid salamanders in ecosystem functions. / Ph. D.

The overall goal of this project was to provide baseline data on amphibian species richness, relative abundance, and habitat use for a long-term landscape ecology study on MeadWestvaco industrial forest in the Allegheny Highlands of West Virginia. From results of area-constrained daytime searches (10 m x 10 m plots) across the landscape, I developed 9 regression models to predict amphibian relative abundance. I constructed models for each year for all plots on all habitat types, plots that were in a Stream Management Zone (SMZ), and plots that were in upland, or non-SMZ, habitat. Distance to perennial or ephemeral streams or perennial ponds (SMZ classification), the amount of available rocks along transects, and site index were the 3 most important habitat variables in models for all plots combined and were responsible for 24-32% of the inherent variation in population relative abundance. Other habitat variables that were significant in models were year, % canopy cover, the amount of available woody debris of decomposition classes 3-5 along transects, % woody stems (<7.5 cm DBH), soil pH, and % herbaceous vegetation. R2PRESS values for all 9 models ranged from 0.08 to 0.35. Amphibian relative abundance showed positive relationships with all significant habitat variables with the exception of year and % woody stems. In natural cover object use/availability analyses, I discovered salamanders preferred rocks over woody debris, relative to the amount available of each. Salamanders preferred flat rocks to any other shape, flagstones to any other type of rock, and rock lengths in the 31-40 cm class. Preferred wood widths were in class 5-10 cm, while preferred wood lengths were in class <50 cm; salamanders exhibited strong preferences for wood in higher states of decomposition (class 3-5). I provided baseline, preharvest data for 28-acre reference areas on 9 forest compartments scheduled for clearcuts. I sampled all 9 reference areas preharvest and sampled 3 during year 1 postharvest using coverboard and night plot surveys. On these 3 areas, species richness declined from preharvest to postharvest, but species diversity showed little change. Overall relative abundance declined significantly preharvest to postharvest with coverboard sampling (p=0.0172) and night plot sampling (p=0.0113). At coverboard stations, relative abundance declined significantly from preharvest to postharvest at a distance of 5-10 m (p=0.0163) and 40-50 m (p=0.0193) away from adjacent mature forest. Finally, using Pianka's index, I compared the night plot and coverboard sampling techniques in terms of proportions of the 4 most common species captured. These sampling techniques on average were >80% similar for all reference areas. / Master of Science

Environmental and anthropogenic stressors negatively affect amphibians in a variety of ways, often increasing their vulnerability to pathogen infection and mortality. Sampling for the pathogenic fungus Batrachochytrium dendrobatidis (Bd) was conducted in order to: 1) determine the presence of chytrid infection in stream-associated plethodontid salamanders of southeastern Kentucky, and 2) evaluate differences in infection intensity between salamanders residing in intact forest streams, timber-harvested streams, and surface-mined streams. During 14 sampling sessions occurring between March, April and May of 2013, DNA samples from 306 individual salamanders within 8 species from the family Plethodontidae were collected; additional amphibians (i.e. frogs, newts) were opportunistically sampled when encountered. Approximately 2.1% of the salamanders and 50% of the frogs sampled from intact streams, 2.3% of the salamanders and 80% of the frogs sampled from the harvested streams, and none of the salamanders and 100% of the frogs sampled from the mined streams tested positive for Bd. No significant differences in occurrence of Bd or infection intensity were detected between the treatment sites (x2 = 0.59; p-value = 0.75), or between individuals of a species between different treatments (see tables). These findings are the first to demonstrate that Batrachochytrium dendrobatidis is present in amphibians of eastern Kentucky.

No description available.

Amphibians, because of their semi-permeable skin, sensitivity to changing microclimates, and important role in ecosystems, are often viewed as indicators of ecosystem health. They make excellent organisms for studies on the effects of silvicultural practices. My goal was to provide recommendations for forest management in the southern Appalachians so that harvesting operations are compatible with maintaining healthy populations of forest amphibians. I tested previously created habitat models that determined the most important habitat characteristics for salamanders. I counted salamanders in 240 10 x 10 m plots located in the MeadWestvaco Wildlife and Ecosystem Research Forest in north-central West Virginia. We also collected a variety of habitat data in these plots to predict salamander abundance with previously created models. These simple linear regression analyses of predicted versus observed values suggest for most models (7 out of 9) a weak relationship between predicted and observed values (R2 from 0.0033 to 0.2869, p from < 0.0001 to 0.7490). However, one of the models showed characteristics suggesting that it predicted new data as well or better than the original data, and therefore was the most accurate at predicting salamander abundance, and could be used for management purposes, although there was still much unexplained variation. This model included the variables woody stems (< 7.5 cm DBH), available rock, riparian status (i.e., within 15 m of a stream), percent overstory canopy cover, and available highly decomposed woody debris (decomposition classes 3 to 5). All of these relationships were positive except for woody stems, suggesting that in order to maintain healthy populations of salamanders, we should protect areas next to streams, with high amounts of rock, decomposed woody debris, overstory canopy cover, and few woody stems. I also examined the immediate effects of clearcuts on salamander movement and population estimates. I batch marked salamanders in plots at the edges of a clearcut, and in a control plot. Using the Schnabel estimator, I estimated population sizes in each plot. I then compared population estimates pre- and post-harvest on the interior (harvested) and exterior (unharvested) sides of the plots, taking into account the control plot. I also examined adult-juvenile ratios and movements from one side of the plot to the other. I found no significant changes (p > 0.05) following harvest in any of these measures, suggesting that salamanders do not move out of the harvested area post-harvest, at least over the short term (10 months of this study). This suggests that a longer period of time (> 1 year) is required to observe the population declines detected in most studies. / Master of Science