Glossary Major issues and findings Instream and riparian habitats Habitat characteristics can affect biological communities in many different ways. For example, trees along streambanks provide shade, erosion protection, and leaf litter to a stream.
Several factors can affect aquatic habitats, which then affect biological communities.
Many habitat characteristics appeared to be influenced more by basin size than by land use. Physiography, geology, basin size, and land use are among the factors that can affect aquatic habitats. Sites with larger basins tend to be wider, deeper, more sinuous streams with greater water velocity and larger canopy angles. Sites with smaller basins tend to have steeper basin and stream gradients. Small streams in agricultural areas generally have fewer trees and other woody plants in the riparian zone than do small streams in forested areas.