Riparian (i.e., stream side) forests are known to restrict light availability and plant growth in streams while providing organic matter that fuels stream food webs. Lateral interactions of this type generate intimate links between terrestrial and aquatic systems. There are equally strong upstream and downstream linkages within streams. By altering the linkages between terrestrial and aquatic elements, forest harvest is a disturbance that influences both hillslope and stream subsystems of watershed landscapes. Riparian processes may dictate how hillslope disturbance influences streams. In this project, the investigators address how interactions between riparian vegetation and streams influence stream responses to forest clear-cutting. They focus on the role of riparian vegetation through comparative studies among watersheds where clear-cutting will remove upslope vegetation but leave riparian zones of differing widths. Two research elements are designed to, 1) address how riparian vegetation buffers disturbance to the stream and organizes lateral linkages between terrestrial and lotic ecosystems, and 2) quantify in-stream gradients or 'recovery distances' when different widths of riparian vegetation remain after forest harvest. Response variables include aspects of the stream's physical template (sediment, light, heat), organic matter dynamics (leaf breakdown), biogeochemistry (nutrient composition and concentration), and biotic composition. search. The project will interact directly with members of the NSF Coweeta LTER program and further development of the research and education infrastructure. Finally, results will advance our understanding of disturbance and its influences, link research and policy formation, and address manager's concerns for southern Appalachian watersheds.
