EFFECTS OF RAINFALL ON COMMUNITY COMPOSITION AND STRUCTURE OF CEDAR GLADES

Cedar glades are treeless ecosystems with shallow soil or exposed limestone and are a hotspot of plant endemism in the Southeast United States, predominantly in middle Tennessee. Soil depth is a major factor which influences glade vegetation, and annual rainfall and temperature have increased over time and are predicted to continue. This increase in rainfall has occurred due to the “heat island” effect of Nashville. With an increase in water, we predicted that the number of species, plant growth, and reproduction will increase due to self-thinning and additional water supplies. We studied the effects of rainfall on community composition and structure of the Flat Rocks State Natural Area. Four treatments of varying water regimes were established and examined for differences in number of species, coverage, and flowers in plots with diameters of 50 centimeter. Data were analyzed by RMANOVA, and results showed that there was little variation among treatments, with the number of species and amount of coverage remaining constant. Results may be due to the inability of constructed shelters to restrict rainfall during some storms due to high amounts of surface flow.