9411975 Foster Forest ecosystems worldwide are changing in response to direct and indirect human activities. These present a significant challenge requiring interpretation of the driving variables across wide temporal and spatial scales. These dynamics also present an opportunity to evaluate the mechanisms regulating ecosystem responses. Harvard Forest LTER I assessed temperate forest response to human (atmospheric deposition and climate change) and natural (wind damage) disturbances. The research was structured around five primary areas: (1) retrospective studies of long-term changes in forest composition, disturbance, and environment; (2) studies of current forest conditions, (3) experimental manipulations to evaluate forest response to disturbance, (4) modeling studies of responses to disturbance over a range of temporal and spatial scales; and (5) cross-site studies. Results from LTER I have transformed understanding of forest response to disturbance and have emphasized the importance of integrated studies across time, space and discipline. In particular, results document that temperate forests must be interpreted in the context of past disturbance, particularly land-use. LTER II research is focused on the study of legacies of human land-use on modern regional scale forest processes. Studies will continue to emphasize keystone long-term experiments and measurements with a focus on the five LTER core areas. New studies will (1) strengthen the temporal and spatial resolution; (2) evaluate population responses to disturbance and patterns of species distribution; (3) assess human-induced alteration of ecosystem function, especially C and N dynamics; (4) evaluate controls on C exchange at leaf to stand levels; and (5) synthesize our work across scales through continued modeling, inter-site, and comparative studies.
