Community composition and diversity of ericoid root associated fungi at different elevations in the southern Appalachian Mountains

Toyota Auditorium, Howard H. Baker Jr. Center for Public Policy

Mountains are among the most floristically diverse areas on earth. This is due to the mountain’s perturbation of weather fronts frequently causing increased precipitation, and the temperature gradient caused by ascending higher into the atmosphere. Due to the changes in temperature and precipitation across elevational gradients, associated differences in edaphic conditions such as C/N are also expected to occur. Differences in moisture, temperature, and edaphic conditions may drive changes in the diversity and composition of root associated fungi. Rhododendron maximum is an endemic species found at all elevations in the Southern Appalachians. This study focuses on the dynamics of ericoid mycorrhizal fungal diversity and colonization levels in R. maximum roots along elevational gradients in the southern Appalachian Mountains. To address this we sampled roots and soils from three iso-elevational transects from high to low elevations at two locations. Root associated fungi were cultured from the roots. DNA amplified from these cultures was typed by restriction fragment length polymorphism (RFLP) analysis of the ITS regions and representatives from each group were sequenced. Root colonization was quantified by counting 3 mycorrhizal hyphae at random locations within the root using light microscopy. Preliminary analysis indicates that colonization, diversity, and species composition of fungi within R. maximum roots may be correlated with changes in elevation. This research will provide valuable information on how R. maximum interacts with fungi that inhabit the range of environments in which this species is found.