Forest structure classification in the North Columbia mountains using the Landsat TM Tasseled Cap wetness component

The goal of this study is to determine the potential of satellite remote sensing image data as a predictive measure of forest structural complexity and stand age. Empirical relationships between forest structural parameters and Landsat Thematic Mapper data were analyzed for a sample of cedar/hemlock, Engelmann spruce/subalpine fir stands, near Revelstoke, British Columbia. The methods used to measure forest stand structure are outlined, followed by a discussion of the correlation analysis between field variables, and the creation of a structural complexity index (SCI) derived from a principal components analysis of several individual stand variables. TM Tasseled Cap wetness values were highly correlated to stand age and structural complexity,for mature and old growth stands. The spatial distribution of TM Wetness values was shown to be related to the vegetation composition and structure of climax communities within two major biogeoclimatic subzones that occupy the region. Empirical relations between TM Wetness and seral and late seral stand structure were variable. A heterogeneous species composition of these communities may explain the weaker statistical relationships. The results support the application of the TM Wetness component for mature and old growth forest structural classification and habitat mapping within the study area.