Predictive mapping for tree sizes and densities in southeast Alaska

The Forest Service has relied on a single forest measure, timber volume, to meet many management and planning information needs in southeast Alaska. This economic-based categorization of forest types tends to mask critical information relevant to other contemporary forest-management issues, such as modeling forest structure, ecosystem diversity, or wildlife habitat. We propose the joint distribution of tree density and mean tree diameter as a more comprehensive set of forest measures. Focusing on those measures, we build a predictive-mapping model by using existing geographic information system data resources and existing ground-sampled inventory data. The utility of our predictive-mapping model will need to be tested with additional intensive ground-sampled data and in applications that involve forest managers, planners, and biologists. Such tests will reveal the modelʹs utility in addressing contemporary forest-management problems and information needs.