Ecology and Evolutionary Biology Commons^™

Movement Behavior And Metapopulation Connectivity Of Stream Salamanders In Response To Disturbance Events, Kathryn M. Greene

Theses and Dissertations--Biology

Metapopulations are shaped by the dispersal between populations in a landscape. Disturbance events can disrupt this connectivity resulting in local population extinction. For my dissertation, I used a combination of empirical and theoretical techniques to examine dispersal in response to disturbance and assessed it’s population-level consequences. My research used capture-mark-recapture sampling techniques to evaluate stream salamander movement in response to (1) a supraseasonal drought and (2) mountaintop-removal-mining (MTR) and valley-filling (VF) and (3) agent-based simulation modeling to evaluate population extinction risk in response to varying dispersal and mortality rates.

First, I evaluated the effects of a supraseasonal drought, a severe …

Competition And Herbivory Influence The Survival, Growth, And Physiology Of Native Tree Seedlings In The Kentucky Inner Bluegrass Savanna-Woodland, James D. Shaffer

Theses and Dissertations--Biology

Terrestrial plant communities are shaped by competition for resources, herbivory, and abiotic processes. Savanna systems represent a dynamic coexistence of contrasting life forms (grasses and trees) shaped by competition and disturbance. The Kentucky Inner Bluegrass Savanna-Woodland (KIBSW) is described as an open woodland of shade intolerant species; however, climatic, and edaphic conditions can support closed-canopy forest. After European pioneer settlement (c1750-1800), over 99% of “savanna-woodlands” have been lost. KIBSW remnants are experiencing a recruitment failure, leading to a dominance shift in tree communities. I researched how tree-grass competition and mammalian herbivory influence KIBSW regeneration and maintenance. The KIBSW does not …

Landscape Ecology And Population Genomics Of Two Sympatric Pitviper Species Across A Fragmented Appalachian Landscape, Thomas Maigret

Theses and Dissertations--Biology

Understanding the link between landscape patterns and ecological and evolutionary processes is an important prerequisite for informed wildlife conservation and management, especially in rapidly changing landscapes. Until recently, the inaccessibility of spatial and genomic data sets of sufficient resolution limited our ability to incorporate the impacts of landscape patterns into predictions of ecological and environmental outcomes. In this dissertation, I utilized several high-resolution spatial and genomic data sets to address ecological questions in a rapidly fragmenting landscape in southeastern Kentucky. Overall, my results indicate that large-scale surface coal mining is causing widespread homogenization of landforms, resulting in a uniquely permanent …

Genomic Perspectives On Amphibian Evolution Across Multiple Phylogenetic Scales, Paul Michael Hime

Theses and Dissertations--Biology

Genomes provide windows into the evolutionary histories of species. The recent accessibility of genome-scale data in non-model organisms and the proliferation of powerful statistical models are now providing unprecedented opportunities to uncover evolutionary relationships and to test hypotheses about the processes that generate and maintain biodiversity. This dissertation work reveals shallow-scale species boundaries and population genetic structure in two imperiled groups of salamanders and demonstrates that the number and information content of genomic regions used in species delimitation exert strong effects on the resulting inferences. Genome scans are employed to test hypotheses about the mechanisms of genetic sex determination in …