Institute of Ecosystem Studies

2007 BES Annual Meeting Presentation and Poster Abstracts

Suspended Solids and Particulate Organic Matter in Urban Streams: Hydrologic drivers.
Watts, Tonya
Co-Authors: Kenneth Belt, Tonya Watts, Christiane Runyan, William Greenwood, and Istvan Turcsanyi
Abstract: Fine particles in streams, as total suspended solids (TSS) and the organic fraction, Fine Particulate Organic Matter (FPOM) are highly affected by stormwater runoff magnitudes due to increased catchment transport and movement of channel storage pools. TSS tends to impact lotic communities negatively by smothering organisms and habitats. FPOM is important to lotic food webs and as substrate for microbial processes and food for macroinvertebrates. We discuss the effects of hydrology on TSS & FPOM concentrations and fluxes for four streams of the BES LTER network. TSS and FPOM concentrations responded strongly (increased) to flow rate (e.g., power function slopes of 0.67 and 0.42 respectively) at the suburban Villa Nova site. The % organic matter (of TSS), however, decreased with flow rate (slope = -0.25). Moreover, somewhat elevated flows influenced by recent storms (ie., in a post surface runoff state) also had higher FPOM concentrations than base flow, by factors of 18 (forested), 23 (suburban) and 5 (urban). These results suggest that the altered drainage pathways and strong terrestrial-aquatic linkages of urban catchments can produce very high TSS and FPOM fluxes. This has important implications for aquatic food webs and productivity, for associated pollutants, and the management of these inputs.