INVERSION OF THE LI-STRAHLER CANOPY REFLECTANCE MODEL FOR MAPPING FOREST STRUCTURE

As part of a larger forest vegetation mapping process based on Landsat TM and digitial terrain data, inversion of the Li-Strahler model prov ides estimates of tree size and cover for conifer stands. The vegetati on maps are intended for use in natural resource management by the US Forest Service. Analysis of extensive field data in the form of ''test '' stands from four National Forests indicate the following about the Li-Strahler model: 1) the underlying assumptions of independence betwe en tree size and crown shape are valid, 2) the means for tree geometry parameters vary between forest types, 3) estimates of forest cover ar e reliable, and 4) estimates of tree size are unreliable due to the br eakdown in the relationship between image intra-stand variance and tre e size. Improvements in estimates of tree size will require additional data beyond a single Landsat TM image, with multidirectional data a p romising possibility.