Fig. 5. Best-fit regressions of leaf chlorophyll a and chlorophyll b concentrations versus leaf reflectance (R), transmittance (T), and absorptance (A) band ratios. Regressions were based on a power function as indicated atop the figure and data combined among the four planar-leaved species. Regression parameters, including the coefficient of determination (r²) and standard deviation of the estimate (s), are listed for each regression (168 samples).