The percentage of wetlands in a catchment accounted for about half of the variance in transformed data for concentrations of dissolved organic carbon (DOC) in 42 Nova Scotian streams draining catchments with 11 different kinds of vegetation. Color increased with DOC, as did total dissolved nitrogen (TDN). The color/DOC and DOC/TDN quotients also rose with increasing DOC, indicating a change in the quality of dissolved organic matter with increasing wetland influence. Dissolved Fe, and to a much lesser extent dissolved A1, showed a strong positive correlation with DOC. Stream pH showed a strong negative correlation with DOC, largely from wetlands, and a strong positive correlation with non-marine Ca ~+ weathered from mineral soils. Non-marine SO4 z-from acid deposition had no apparent influence on stream pH and decreased with increasing streamwater DOC in summer, presumably owing to reduction processes in wetlands that mitigated the effects of acid deposition. Apparently, these reduction processes also produced small amounts of dissolved, non-ionic organic sulfur. Non-marine Ca 2+ was related strongly to the percentage of upland hardwood forests in the catchments. Wetlands exert a profound influence on the chemistry of streams, principally through their export of DOC but also because of reduction reactions in their anerobic peats.

A survey of 14 species of Sphagnum has shown that the amino acids and organic acids are essentially those encountered in higher plants. At least one unidentified amino compound occurs in the rare S. strictum. Malic and citric acid are the dominant organic acids, but the amounts of free organic acids in Sphagnum are unusually low. Two tri- and three tetra-saccharides, consisting of fructosylated sucrose, are regular constituents of the neutral fraction of Sphagnum.

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