There is a wide range in threshold responses to urbanization and agriculturalization of catchments.
Riparian buffers have substantial, or little, effect on water-body condition.
I review earlier published work, together with EMAP data from the Appalachians, New England, and Pacific Northwest to help explain differences in disturbance-response plots. Results indicate that organism size, choice of biological metric, location and sub-categories of land use, accuracy and precision of land use measurements, and degree of riparian fragmentation and permeability all cloud pattern detection.