We are investigating the joint effects of habitat fragmentation and climate change on native plant populations using Pityopsis graminifolia, a common forb that is native to the Southeastern US. Extreme alterations in the climate have already caused local extinctions; species that were well-adapted to their local environment are unable to survive when faced with a novel climate. Fragmentated habitats, isolated populations with reduced population size, may not be able to maintain positive population growth rates due to reduced gene flow. Small, isolated populations are often genetically depauperate and have reduced potential to adapt to environmental changes, such as climate change. We are also studying a rare congener of P. graminifolia, Pityopsis ruthii, in order to determine if the variation between two congeneric plant species can explain the differences the two species’ abundances. P. ruthii is only found along riparian areas in Polk County, Tennessee. This project is part of a larger collaborative effort to uncover the causes of rarity in plants by conducting experiments with common and rare congeners.
