Date of Award

January 2014

Degree Type

Open Access Thesis

Degree Name

Master of Science (MS)

Department

Biological Sciences

First Advisor

Stephen C. Richter

Department Affiliation

Biological Sciences

Second Advisor

Patrick J. Calie

Department Affiliation

Biological Sciences

Third Advisor

Amy Braccia

Department Affiliation

Biological Sciences

Abstract

An important aspect of conservation biology is understanding how land-use changes impact biodiversity. Ridge-top wetlands are unique habitat for pond-breeding amphibians and the Daniel Boone National Forest (DBNF) contains natural forested ridge-top wetlands in close proximity to constructed wetlands intermixed across the same landscape. Genetic data can be used to address current population status, probability of persistence, and population connectivity. The objective of this study was to determine the amount and distribution of population genetic diversity of wood frogs in natural ridge-top wetlands and what factors influence this. Genetic data were analyzed for nine microsatellite DNA loci from twenty-five wood frog egg clutches at each of five randomly selected natural wetlands. Overall, genetic variation was measured by calculating observed heterozygosity (0.250-0.960), expected heterozygosity (0.270-0.913), and mean allelic richness (8.83-11.95). The results from program STRUCTURE gave support for 3 genetic clusters, and overall FST was 0.054 ± 0.022 SE among populations. Three populations exhibited signs of a recent population bottleneck event within populations. Pairwise FST and DST values were correlated, with DST indicating slightly higher population divergence. Isolation by distance was significant (P = 0.0354; R2 = 0.445), indicating that geographic distance between the wetlands was an important factor explaining genetic differentiation. Future work should focus on expanding the sampling to a larger scale and sampling both natural and constructed wetlands between the sites to understand more fully how the genetic variation is partitioned across the landscape. For example, wood frogs have been observed breeding in both constructed and natural wetlands, which may demonstrate source/sink dynamics, and predation on wood frog eggs in constructed wetlands may decrease overall wood frog genetic diversity over time.

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