Kaplan, L.A., R.A. Larson, and T.L. Bott. 1980. Limnology and Oceanography 25:1034–1043.
Two distinct patterns of dissolved organic carbon (DOC) in transport were observed in a southeastern Pennsylvania piedmont drainage basin under low flow conditions. In relatively undisturbed woodland spring seeps, DOC concentrations increased with distance from the groundwater sources as did the apparent percentage of high molecular weight DOC, changes in pH, color, and phenolic-C paralleled those for total DOC in a seep, while the concentration of carbohydrate-C remained relatively constant. In headwater areas perturbed by humans, cattle, or waterfowl, elevated DOC concentrations decreased rapidly from point source inputs.