FIGURE 3.

Classification of Populus spp. rhizosphere components using different combinations of visible (VIS) and near infrared (NIR) wave bands to produce spectral reflectance images at days 20, 55, 70, and 170 after planting (DAP). Wavelengths of the three VIS bands (upper row) and the VIS–NIR bands (lower row) are 650, 550, and 480 nm, and 886, 679, and 522 nm, respectively. A color photo at DAP 70 and the false color classification scheme are given. Source images were taken under wet soil conditions (see Nakaji et al., 2008 for details). Images courtesy of T. Nakaji, K. Noguchi and H. Oguma, Japan.