Doctor of Philosophy, Miami University, 2009, Zoology

Habitat loss and alteration is a major cause of population declines; thus, habitat conservation is essential for preventing species extinctions. Habitat conservation, however, can be hindered by an inadequate understanding of species' habitat requirements. Pond-breeding amphibians have a biphasic life history, which requires both aquatic and terrestrial habitats; thus, pond-breeding amphibians are particularly vulnerable to habitat alteration because they experience its effects in multiple habitats during successive life stages. The goal of this dissertation was to examine the importance of habitat structure (i.e., vegetation structure, canopy cover) for larval and juvenile pond-breeding amphibians. In the first and second chapters, I assessed how aquatic vegetation structure mediates biotic interactions (competition and predation) for larval amphibians. In the second, third, and fourth chapters, I established that aquatic and terrestrial canopy cover can strongly influence growth and survival of amphibian larvae, as well as locomotor performance, growth, and survival of terrestrial juveniles. Taken together, the findings of my research suggest that, although habitat structure influences growth and survival of larvae, some pond-breeding amphibians appear to be more sensitive to the suitability of their terrestrial habitat; thus, successful conservation of pond-breeding amphibians must involve the preservation of high-quality (i.e., closed canopy) terrestrial habitat and the maintenance of corridors that facilitate juvenile dispersal from natal wetlands to suitable terrestrial habitat.

Committee: Michelle Boone PhD (Advisor); Thomas Crist PhD (Committee Member); Maria Gonzalez PhD (Committee Member); Ann Rypstra PhD (Committee Member); Robert Noble PhD (Committee Member) Subjects: Animals; Behaviorial Sciences; Biology; Ecology; Freshwater Ecology; Zoology