Amphibian Population and Community Characteristics, Habitat Relationships, and First-Year Responses to Clearcutting in a Central Appalachian Industrial Forest
Williams, Lori Ann
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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 PiankaÃ Âs 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.
- Masters' Theses