Knickpoint effects on macroinvertebrates, sediment, and discharge in urban and forested streams: urbanization outweighs microscale habitat heterogeneity

• DOI: 10.1899/11-010.1
• Publication Date: 2012-05-15T21:20:00Z
• Authors: Jeffrey D. Muehlb...; Martin W. Doyle
• Keywords: Spatial heterogeneity; Biota

Knickpoints are dynamic geomorphic formations in the longitudinal stream profile that have long been a subject of interest for geomorphologists, but largely unstudied ecology. We measured discharge, bed sediment, and macroinvertebrate communities around knickpoints forested urban catchments. introduced microscale heterogeneity discharge. This may be important providing refugia benthic biota during low-flow conditions, depending on condition sediment below knickpoint, which was highly variable. In addition, supported unique filterer-dominated community macroinvertebrates not found elsewhere reach. The knickpoint itself also maintain higher overall density comparison to other habitats reach, this prediction only weakly supported. Instead, largest differences metrics were consistently between knickpoints. Decreases density, species richness, diversity from greatly outweighed any within individual sites. Thus, we conclude serve as hotspots biodiversity provide substantial habitat over small area, valley-scale influence catchment land use far outweighs effect these features influencing communities.