Effect of beaver dams on nutrient levels in streams.

Abstract

Beaver dams (two occupied and one abandoned) in northern lower Michigan may affect nutrients in streams. The two alternate hypotheses were that nutrient levels would be lower downstream due to increased phytoplankton levels or that they would be higher due to increased allocthanus inputs. No signficant differences were found, except that there was an increase in total phosphorus when only the active dams were looked at. These results suggest that any effects beaver dams have on nutrients would require longer time periods and more sensitive measures to be detected.