Fig 5. Relationship between cation concentrations and variability in canopy structure and reflectance.

(a) Relationship between soil cation concentrations (the log-transformed sum of Mg, Ca, Na, and K) and coefficient of variation for canopy height. Trend line represents second-order polynomial. (b,c) Average standard deviation for canopy spectra and vertical height profiles, respectively, after grouping by cation concentration quartiles. In (b) and (c), color-coding matches that in Fig. 2d, such that red indicates the first (bottom) quartile, orange the second, green the third, and blue the fourth (top).