The southern Appalachian Mountains are a biodiversity hotspot undergoing rapid development. They harbor unique species and assemblages, and are the source of freshwater as well as a recreational destination for human populations in nearby metropolitan areas. The total rural and urban population of the southern Appalachian region is expected to continue growing at double-digit rates for the foreseeable future, accompanied by conversion of forested land to developed areas. Forests such as those in southern Appalachia have developed under moisture-rich climates, and may be particularly susceptible to the increased droughts predicted as human demand for water increases and as climate changes. This long-term research addresses the complexity of organismal responses to increasing variability in moisture regimes, linking results of basic research to their practical implications. The Coweeta Listening Project and the Coweeta Scholyard Program translate and communicate community-relevant research results to engage society with science in the southern Appalachian Mountains. Educational activities include field-based environmental education and in-classroom support for middle school teachers and students, as well as outreach programs to land owners on the importance of riparian corridor integrity.

This project will continue to examine how hydroclimate variability and the human-modified landscape separately and interactively alter southern Appalachian Mountain ecosystem processes and biotic communities that, in turn, affect the vulnerabilities of regional socio-ecological systems. The research builds on long-term studies across numerous permanent plots within and beyond the Coweeta Basin that include over 20 years of tree demographic data representing more than 350,000 tree-years. Performance and abundance of a suite of herbaceous, invertebrate, and vertebrate species will be measured within and beyond the Coweeta Basin. A large-scale experiment will be used to assess the post-rhododendron removal rates of recovery for vegetation dynamics, soil microbial communities, soil extracellular enzyme activity, and nutrient pools and fluxes. Treatments will examine processes at the interface between terrestrial and stream ecosystems based on intensive plot-scale and extensive reach-scale measurements. Modeling of past and present hydroclimate variability will be used to establish ecosystem function and risks from local to regional geographies. Understanding the relationships between ecosystems, organisms, and their responses to the forces of hydroclimate variability and human activities on the land are essential if ecological science is to anticipate, respond to, and mitigate these changes and the associated vulnerabilities.