POLAR DISTURBANCE AND ECOSYSTEM
type: Concept
definition: The goal of this project is to document pan-arctic changes in large-scale disturbances (thermokarst, fire, insect outbreaks, and forest harvest), relate these to climatic and social change, and to assess their ecological, climatic, and societal consequences in high-latitude ecosystems (tundra and boreal forest). Recent trends suggest that continued high-latitude warming will likely be accompanied by increases in disturbances such as fire, insect outbreaks, thermokarst, and potentially forest harvest and land-cover conversion to grassland or agriculture. These disturbances have qualitatively different effects on the climate system, ecological processes, and therefore society than do those ecological processes that are more continuous functions of climatic change. Large-scale disturbances have the practical advantage that they can be quantified regionally by remote sensing so processes studied locally are more readily extrapolated to large scales. The program builds on existing research programs in Alaska, Canada, Scandinavia, and Russia and on global remote-sensing and inventory programs. We choose a pan-arctic scale so we can relate our results to the functioning of arctic climate system and take advantage of geographic variation in climate and disturbance regime. We also build from national and site-based research programs and databases, providing the opportunity to link processes and local, regional, and global scales. We address the following questions: 1. How have changes in climate affected disturbance regime across the arctic and boreal zones, and how have these changes in disturbance affected climate through changes in trace gas emissions, smoke, and energy exchange? Do feedbacks from land-surface processes to climate buffer or amplify the initial climate trends? In other words, what is the net effect of these high-latitude climate feedbacks on the global climate system? We currently have circumboreal databases of disturbances (fire, insects, and forest harve…
in scheme: projects

P - R
type: Concept