Estimation of forest stand structure from Landsat TM through inversion of the Li-Strahler model

Results from several National Forests over several years indicate the capabilities and limitations associated with the use of the Li-Strahler invertible forest canopy reflectance model in vegetation mapping. On the basis of single date Landsat Thematic Mapper data, inversion of the Li-Strahler model provides accurate estimates of conifer crown cover, but is less reliable for tree size estimation. The problems in tree size estimation result primarily from estimates of intra-stand variance, which are influenced by factors other than stand structure. Key additional factors influencing variance in reflectance within stands are variation in background materials and prior forest management activities. Research continues on the use of multi-angle and finer resolution imagery to improve tree size estimates.