Large-Scale Geospatial Mapping of Forest Carbon Dynamics

Abstract

Digital maps of forest dynamics are emerging as a great tool for the increasingly popular area of forest carbon-offset management. We used a geospatial matrix model (GSM) to estimate the amount of carbon dioxide-equivalent sequestered by the aboveground forest under the assumptions of natural growth, constant climate conditions, no human interference, and no natural disturbance. A digital map database was developed to facilitate research and management at various spatial scales.Despite its low potential to be managed for timber yield and net present value, the Alaska boreal forest—capable of offsetting an estimated 2.90 × 107 Mg of CO2-e annually—represented a significant offset resource for the emerging carbon market. The best carbon offset areas were clustered in the moisture-abundant lowlands along the major rivers whereas the worst ones neighbored the four major Alaska urban developments. It was hypothesized that moisture limitation and inappropriate human interference were the main factors affecting carbon offset ability of the Alaska boreal forest. Albeit limitations commonly associated with empirical geospatial models, the present model provided a useful baseline tool for the estimation of future forest carbon dynamics and carbon credits. Forest carbon offset management was suggested to employ spatial-specific regimes and focus on fire prevention and mitigation.