Figure 7.
Total canopy reflectance (CanR; A and B), transmittance (CanT; C and D), and absorbance (CanA; E and F) in simulated canopies composed of a range of leaf Chl content going from dark-green (500 μmol m−2) to light-green (50 μmol m−2) according to DOY within the growing season. Total values for each optical property were determined by summing the diurnal values for PPFD reflected, transmitted, or absorbed by the canopy divided by the summed total of diurnal incoming PPFD. Simulations were performed assuming leaf reflectance (LeafR)and transmittance (LeafT) covaried according to empirical relationships (A, canopy C, and E; Eqs. 1 and 2) derived from observations of diverse soybean lines (see Fig. 2) spanning a wide range of Chl as indicated by the decreasing Chl displayed on the y axis. Alternatively, canopies were simulated with LeafR set to a negligible value at every Chl (B, D, and F) to show the impact of leaf reflective loss on total canopy optical properties.