Research about Minnesota River basin

USGS2003

Influence of local riparian cover and watershed runoff potential on invertebrate communities in agricultural streams in the Minnesota River Basin

During the summer of 1997, 23 streams in the highly agricultural Minnesota River Basin were studied to determine the influence of local riparian cover conditions (wooded or open) and watershed runoff potential (high or low) on invertebrate community composition. A two by two-factorial analysis of variance was used to determine differences in invertebrate community measures among the design classes While it is difficult to determine the relative influence of watershed runoff potential and local riparian cover, invertebrate communities may be more strongly influenced by local wooded riparian cover than by watershed runoff potential. Invertebrate community measures indicate greater degradation at the open riparian cover, high runoff potential sites and less degradation at the wooded riparian cover, low runoff potential sites. In addition, differences between streams with wooded riparian cover and sites with open riparian cover were greater in watersheds with high runoff potential. The variance explained by riparian cover and runoff potential is relatively independent of other land-use effects. Wooded riparian cover influences invertebrate community composition by its relation to the other physical environmental variables. This study indicates that wooded riparian cover may be effective in maintaining stream biotic integrity in watersheds dominated by agricultural land use.

Iowa, Minnesota, South Dakota↗

USGS2000

The relation of fish community composition to riparian cover and runoff potential in the Minnesota River basin, Minnesota and Iowa, 1997

The relation of fish community composition to riparian cover and runoff potential was investigated in 20 streams in the Minnesota River Basin during the summer of 1997 as part of the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Program (fig.1). Analysis of variance statistics indicated significant differences in the composition of the fish community due to both riparian cover (wooded or open) and runoff potential (high or low). An Index of Biotic Integrity (IBI), species richness, and diversity were used to measure the community response and health. Fish communities in streams with significant wooded riparian cover had higher IBI scores, species richness, and diversity than streams with little wooded riparian cover. Streams with low runoff potential had higher IBI scores and species richness than streams with high runoff potential. IBI scores and species richness responded independently to riparian cover and runoff potential. Although both factors were important, riparian cover influenced fish community composition more than runoff potential in these streams, indicating that local factors (close to the stream) dominate landscape or basin-wide factors (Stauffer and others, 2000).

Iowa, Minnesota↗