Parameters, a and b, and associated statistics from the fitting of an exponential distribution r(z) = a e−bz to the average root profile in the vertical (z) direction.

The parameters aL, bL, and associated statistics from the fitting of an exponential distribution rL(z) = aL e−bLz to the average root density (figure 3) are shown in italic fonts. The distribution is calculated as an average of three plots (20 soil pits per plot) at five depths.