ANALYSIS OF CONIFER FOREST REGENERATION USING LANDSAT THEMATIC MAPPER DATA

Landsat Thematic Mapper (TM) data were used to evaluate young conifer stands in the western Cascade Mountains of Oregon. Regression and correlation analyses were used to describe the relationships between Tm band values and age of young Douglas-fir stands (2 to 35 years old). Spectral data from well regenerated Douglas-fir stands were compared to those of poorly regenerated conifer stands. TM bands 1, 2, 3, 5, 6, and 7 were inversely correlated with the age (r greater-than-or-equal-to - 0. 80) of well regenerated Douglas-fir stands. Overall, the ''structural index'' (Tm 415 ratio) had the highest correlation to age of Douglas-fir stands (r = 0.96). Poorly regenerated stands were spectrally distinct from well regenerated Douglas-fir stands after the stands reached an age of approximately 15 years.