Fig. 6. Depth of soil horizon boundaries vs. transitions in residual flux rate. Depths of inflection points in the cumulative plots (Fig. 4), signifying minor differences in flux, were compared with depths of soil horizon boundaries described in the field. Data are included from all nine profiles for each vegetation type. The chaparral data have a higher coefficient of determination. However, correlation for the 0- to 53-cm depth (the depth range for which data are available for grass) is similar to that for grass. Neither regression equation has a slope that is statistically differentiable from one.