Dynamics of water chemistry in hardwood and pine ecosystems.

This paper summarizes the alteration of water chemistry during its passage through different ecosystem compartments for three forest types in the Southern Appalachians. There is a significant depletion of hydrogen ions in pine and oak-hickory forests as water passes through successive canopy, forest floor, and soil compartments. The net change in H7 concentrations between precipitation and stream water is equivalent to about 2 pH units; i.e., pH increases from 4.5 to 6.5. Patterns of base cation changes through compartments are generally similar for the two pine and the hardwood forest types, but with a few exceptions. Patterns between forests appear to be most different for NO3 and SO4, which are mediated by microbial transformations.