The “Urban Stream Syndrome” is a term that refers to a group of predictable negative impacts to stream ecosystems due to the alteration of the natural hydrologic regime associated with urbanization including increases in the volume and intensity of storm water inputs to streams, channel erosion, streambed sedimentation, and nutrient and pollutant concentrations. These negative impacts of urbanization degrade the habitat available to the aquatic biota in streams. The decline in aquatic insect taxa richness due to urbanization has been well documented. However, the impact of the stressors associated with the increased stormwater flashiness to the composition of the aquatic insect assemblages’ taxa and trait richness and diversity is not well known.
For my dissertation, I proposed three research studies designed to improve the understanding of how the increased stormwater from urban areas impacts the aquatic insect assemblages’ taxa and trait richness and diversity. To do this, I first examined a 26-year data set to study the impact of land use changes on biodiversity and ecosystem function in stream ecosystems in watersheds that span a gradient of impervious cover and stream habitat conditions. Next, to better understand the impact of urbanization on biodiversity and ecosystem function, I examined the relationship between aquatic insect taxa and trait richness and diversity and stream habitat diversity at the watershed scale and the importance of microhabitats at the reach scale. Finally, to better understand stormwater impacts on aquatic insect assemblages, I compared macroinvertebrate taxa and trait richness and diversity in 2 adjacent headwater tributaries that received stormwater runoff through different processes (stormwater infrastructure verse natural overland and subsurface processes).