ABSTRACT OPP-9614038 RASTETTER MARINE BIOLOGICAL LABORATORY The goal of this project is to quantify and to improve understanding of changes in carbon storage in terrestrial Arctic ecosystems. The balance between canopy and soil carbon cycling processes, and the interactions between them and soil moisture, will help determine whether the Arctic develops as an important sink or source for carbon. This project will focus specifically on modelling canopy carbon and water exchange, and synthesize information gathered in experimental components of existing programs. A hierarchy of models will be employed that will produce robust regional models of canopy carbon and energy exchange, derived from validated process-based models. The project will integrate information collected from Toolik Lake LTER site, make linkages that will facilitate the construction of simpler and coarsely-scaled models of canopy proecess, and third, create suitably scaled representations of canopy process for use by other regional modelling efforts.