Fig. 3. Depth profiles of regolith water Cl^– concentrations. Water Cl^– was measured on the same samples used in the water potential analysis. (a) Vegetation means derived from all profiles under each vegetation type (n = 9). The same significant changes are present under grass vegetation at 70 and 100 cm. The high spike at 145 cm for chaparral is due to a single depth increment at one site and suggests local water uptake by a nearby root. (b) Position means for chaparral watersheds (n = 3). Note that the Cl^– concentrations from the summit element are significantly lower within the upper 50 cm. (c) Position means for grass watersheds (n = 3). Standard error is shown for each depth increment.