The type and amount of organic matter, particulate and dissolved, present in surface water has a very real effect upon the ecological status of the stream itself as well as downstream ecosystems. The objectives of this study were to evaluate the quantity of certain N and C compounds in stream water from 4 communities; pine and juniper, mixed conifer, spruce and fir, and aspen. These studies were performed on gauged watersheds to calculate absolute quantities. Significant differences were found between the streams of different vegetational communities. Concentrations of inorganic N and dissolved C compounds were highest in the stream water of the mixed conifer community. For each community the highest concentrations of all compounds occurred during the high stream discharge following snow melt. Concentrations of tannin and lignill also were highest in the mixed conifer community while phenol concentrations were high in both the mixed conifer and aspen communities. A number of factors are involved including organic matter accumulation, decomposition rates, plant tissue composition, evapotranspiration, and stream discharge.

Project No. 3109-146