Aquatic invertebrate use of submersed rootmat habitat created by eight woody riparian species

Submersed fine roots (rootmats) may be important habitats for larval fish and aquatic invertebrate species.  Prior studies indicate they have a distinct faunal composition compared to other in-stream habitat types.  Woody species often have the highest densities of these fine roots at the stream bank where hydraulic stress creates undercut banks. The objective of this study is to examine the invertebrate assemblages inhabiting the roots of eight common woody species in Cuyahoga Valley National Park, Ohio (CVNP).

We collected 50 rootmat samples from pools across 12 CVNP streams. Coarse particulate organic matter, root morphology, and physiochemical variables were measured to characterize the local habitat at each location.  Diversity indices and multivariate techniques are being applied to the dataset to investigate the role of rootmats as habitat. Additionally, invertebrate assemblages of rootmats will be compared to invertebrate assemblages found in adjacent riffles. 

Preliminary results indicate that members of the midge subfamily chironominae and the midge tribe tanytarsini are often dominant and diverse in the samples.  Midge assemblages appear consistent among various tree species, however further evaluations may reveal species trends toward specific habitat preference. Correspondence analyses using species data suggest invertebrate assemblages are clearly different in adjacent rootmat and riffle habitats.