Assessing Wetland-Riparian Amphibian and Reptile Communities of the Mid-Atlantic Region

Abstract

The dependency of many amphibian and reptile species on aquatic habitats is well known. Here, we summarize four studies that investigated aspects of herptile life histories and developed models and tools to assess their responses to disturbance and changing environmental conditions. An Amphibian Index of Biological Integrity (AIBI) was developed and tested for amphibian communities found in headwaters of the Ridge and Valley ecoregion of Pennsylvania. The AIBI demonstrated how amphibian species are significantly and negatively affected by changes in land use, and how conserving an intact wetland-riparian corridor is extremely important for maintaining amphibian biodiversity. A study of pond-breeding assemblages of amphibians in the Delaware Water Gap National Recreation Area demonstrated their response to a hydrologic gradient of connectivity. The degree of pond isolation, as defined by hydrologic connectivity, land use, and predator access, significantly impacted these assemblages, and thus, can be used as predictors of amphibian species occurrence. This study confirmed the importance of protecting isolated wetlands in the landscape. A third study investigated the response of the stream-dwelling plethodontid salamanders to acidified conditions caused by atmospheric deposition and acid mine drainage in western Pennsylvania. This study revealed that stream plethodontid abundance, presence, and diversity were severely suppressed in acidified environments. The value of stream salamanders as a bioindicator was confirmed by this and a subsequent study of similar assemblages throughout the Mid-Atlantic Highlands. The final study involved development of a Habitat Conservation Plan (HCP) for the federally threatened bog turtle, a wetland-dependent reptile with a stronghold in southeastern Pennsylvania and northwestern Delaware. Teams of investigators from multiple organizations assessed ecological, legal, socioeconomic, and land management factors to arrive at a recommended HCP. A process to locate and operate conservation banks in prime recovery areas was established. Through a system of credit generation, critically important habitats for breeding colonies of bog turtle would be protected.