As for Larix gmelinii, in the image acquired on September 5, 1999, the reflectance of band 5 has the highest correlation with forest age (, ), while the reflectance of band 2 is not significantly correlated with the forest age (). The reflectance of bands 3, 5, and 7 shows similar trends changing with the age. It declines to minimums at stand age of years and then increases. The reflectance of band 4 shows an opposite trend changing with stand age, peaking when stands are years old. In the image acquired on January 27, 2000, the reflectance of all bands is significantly correlated with forest age, with in the range from 0.024 (band 7, ) to 0.095 (band 1, ). The spectral response of all bands to stand age is similar, with reflectance minimizing when stands were to 100 years old. For Betula platyphylla, in the leaf-on image acquired on September 5, 1999, the reflectance of all bands decreases quickly with the age when forest is young and then changes marginally. The reflectance of bands 1, 2, 3, and 4 has stronger correlations with the forest age than that of bands 5 and 7 in the leaf-off image acquired on January 27, 2000. The highest values are 0.579 (band 5, ) and 0.447 (band1, ) for the leaf-on and leaf-off images, respectively.