Date of Award

12-2018

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Division of Agriculture (SAFES)

Committee Member

Dr. Kyle Barrett, Committee Chair

Committee Member

Dr. Catherine Jachowski

Committee Member

Dr. Rob Baldwin

Abstract

Urbanization is among the largest threats to amphibian populations through habitat fragmentation, isolation, and outright destruction. Urban open spaces, such as parks and golf courses, have the potential to provide amphibians with suitable habitat within an urbanized matrix. During the spring and summer of 2018, I conducted dip net surveys and active call surveys to determine the presence and abundance of anurans at 51 wetland sites within the Piedmont ecoregion of South Carolina. Nearly one-third of these wetlands were located within urban open spaces, while the others were situated along a rural – urban gradient. Impervious surface and road density surrounding the wetlands were measured at a core habitat scale (300 m) and average maximum migration scale (750 m). Urban Open Space wetlands were found to have levels of impervious surface similar to High Urbanization wetlands at the larger scale and were intermediate between Low and High Urbanization wetlands at the smaller scale. Road densities were higher at Urban Open Space wetlands at both scales compared to Low and High Urbanization sites. Species richness decreased as impervious surface and road density increased among all wetlands. Wetland category was not a significant driver explaining species richness, but β-diversity was higher among Urban Open Space wetlands than either Low or High Urbanization wetlands. I also evaluated species-specific relative abundances as a function of wetland type (Urban Open Space, High Urbanization, or Low Urbanization), several within-wetland variables and two landscape-scale covariates. No species were influenced by wetland type, however impervious surface had a negative influence on the abundance of one species whereas road density negatively affected three species of anurans. Urban Open Space wetlands did not appear to increase suitability for anurans relative to urban wetlands, instead showing higher variability in species composition; perhaps attributable to the diversity among sites represented in the Urban Open Space category. Conservation efforts conducted within open spaces should attempt to focus on issues not only at an individual wetland scale, but also at larger scales surrounding the open spaces themselves. Understanding how urbanization at various spatial scales effects anuran species can bolster amphibian conservation efforts in urban matrices.

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