Relationship between the riparian vegetation environment and stream benthic invertebrate communities at two scales

L. Rios and R.C. Bailey. Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7

Riparian vegetation in streams of the Upper Thames River Watershed in Southwestern Ontario is a mosaic of habitat patches created by differences in land use. The objective of this study was to measure, describe, and interpret the relationship between the riparian vegetation and benthic macroinvertebrate communities in streams at two different scales. A combination of GIS analysis, historical data, and field observations were used to describe the riparian vegetation and the benthic macroinvertebrate community at over 100 sites. Multivariate analysis illustrated the gradient of riparian environments from open, primarily herbaceous agricultural land to closed canopy environments with multi-layer, woody vegetation. Some of the variation among sites in the benthic macroinvertebrate community was explained by this variation in the riparian environment at both the local (site) and drainage basin scales.