The influence of beaver dams on animal communities of streams and surrounding riparian zones

Beaver dams tend to increase habitat heterogeneity by breaking up streams into lentic and lotic sections. I investigated the impact of beaver dams on macroinvertebrates in and near Cart Creek in Newbury, MA. I found that the high spatial density of dams on this small creek suppresses aquatic species diversity, but the ponds might be increasing the species diversity of terrestrial macroinvertebrates. I also found that significant trophic subsidies are present between aquatic and terrestrial organisms, with terrestrial predators feeding on aquatic animals and aquatic herbivores and detritivores feeding on leaf litter and other detritus fallen into the creek from the land.