The Cumberland Plateau Disjunct Paradox and the Biogeography and Conservation of Pond-breeding Amphibians

Abstract

I inventoried 26 vernal pools on the Cumberland Plateau in Tennessee to assess amphibian species richness and clarify distribution patterns. Eighteen pond associated species were found out of 21 known to breed in the region, which is comparable to the richness of temporary wetland habitats throughout the southeastern U.S. Many of the observations were new county records and I extended the southwestern edge of the entire range of the wood frog (Rana sylvatica) nearly to the Alabama state line and onto Walden's Ridge for the mole salamander (Ambystoma talpoideum). Combining the overall distribution patterns with evidence from fossil, geological, palynological and recently published phylogeographic studies helped to clarify disjunct amphibian distribution patterns on the Cumberland Plateau. Most amphibian range disjunctions appear to have arisen from species-specific responses to long running cycles of climate driven habitat change, rather than wholesale community-wide shifts. Thus, the two paradoxical hypotheses for Cumberland Plateau disjuncts were both over simplifications of more complex biogeographical processes.