Using a GIS to model the effects of land use on carbon storage in the forests of the Pacific Northwest, USA

Ameliorating the effects of global climate change on natural and intensively managed ecosystems will require considerably more knowledge than we currently possess about the responses of ecosystems to changes in temperature, moisture and natural and human-caused disturbance. A central question yet to be answered is the role of the terrestrial ecosystem in regulating atmospheric concentrations of greenhouse gases (Houghton et ai, 1987; Keeling et al., 1989; Tans et al., 1990). Answering this question largely depends on our ability to assess how carbon storage in the terrestrial ecosystem will change. Two primary factors can directly alter terrestrial carbon stores: (1) effects of changing climate and atmospheric CO2 concentrations on ecological processes, and (2) natural

disturbances and land use. This study focuses on land use effects, a critical topic globally, and one that has been identified as a priority issue in research initiatives at national and international levels (ISSC, 1990).