9632854 Coleman This research will continue investigations on the extent and complexity of natural and human-caused disturbances, and how they interact with ecological processes along environmental gradients in the landscape. This work builds upon extensive long-term studies of landscape processes in the southern Appalachians and spans four levels of resolution (plot, watershed, landscape and region) in the Little Tennessee and French Broad River basins. Individual and interacting effects of disturbance and environmental heterogeneity on populations, communities, and ecological processes forms the unifying theme of this proposed LTER research. The research team will focus on three areas of inquiry: (1) characterization of disturbance and environmental heterogeneity in the southern Appalachians, (2) effects of disturbance and environmental heterogeneity on populations and communities, and (3) effects of disturbance and environmental heterogeneity on biogeochemical cycling and ecosystem processes. The project builds on extensive understanding of disturbances occurring with the Coweeta basin and continues to characterize environmental heterogeneity, maintaining continuity in the 60+ year record for some variables. As the focus expands to the southern Appalachian region, historical fire regime and socio-economic drivers of land-use change will also be considered. The effects of disturbance and environmental heterogeneity on plant and animal populations will be assessed at a range of scales and key questions will be addressed on the effects of resource variability on terrestrial and aquatic biodiversity. Using a combination of new studies and continued long-term measurements, investigators will examine the role of environmental heterogeneity and disturbance in regulating ecosystem pools and processes in streams, riparian zones, and forests. This research approach utilizes an integrated program of long-term field measurements, experiments and modeling.
