History, dispersal limitation, and environment shape the current and future ranges of forest herbs of the Southern Appalachians

University of Minnesota M.S. thesis. August 2018. Major: Plant Biological Sciences. Advisor: David Moeller. 1 computer file (PDF); iii, 53 pages.As climate changes, favorable climatic conditions for some species might cease to overlap with their current geographic ranges, due to low dispersal rates, barriers to dispersal, or lack of microhabitats, among others. Here, we focus on herbaceous paleoendemics plants in the Southern Appalachian Mountains, possibly threatened by climate change. We developed species distribution models to identify areas of predicted current suitable habitat, both inside and outside of ranges, and evaluated the extent to which these areas shift or move northwards under various future climate scenarios. We discovered predicted suitable habitat in northern areas disjunct from current ranges, suggesting dispersal limitation. We also found severe reductions in predicted suitable habitat under future climate scenarios, both in geographic extent and in percent suitability. Results from models created using more widespread species reinforced these results. Thus, it is imperative to employ conservation efforts in order to prevent species declines or extinctions