This project is a study of how a native prairie perennial plant is able to persist in an oak savannah woodland developed on a sand plain. The project is based on the notion that explanations of persistence are affected by the spatial scale under study. The study species for this project is Penstemon grandiflorus (Scrophulariaceae) a plant native to midwestern sand prairies and savannahs. Specifically, it is proposed to determine how Penstemon persists at three spatial scales: the plant neighborhood, individual openings in the savannah/forest complex, and the overall landscape. The way in which, pocket gophers, and processes associated with succession interact to affect the persistence of this species at the three different scales will be examined. Small experimental plots will be used to test hypotheses involving persistence at the scale of the neighborhood; larger long-term observation plots will be used to test hypotheses regarding successional dynamics of openings; and aerial photography and computer mapping will be used to test hypotheses at the landscape level.