You are here:
Burial affects the biogeochemistry of headwater streams in a midwestern US metropolitan area
Citation:
BEAULIEU, J., S. S. Kaushal, P. MAYER, M. J. Pennino, C. P. Arango, D. A. Balz, K. M. FRITZ, AND B. C. Hill. Burial affects the biogeochemistry of headwater streams in a midwestern US metropolitan area. Presented at Society for Freshwater Science Annual Meeting, Louisville, KY, May 20 - 24, 2012.
Impact/Purpose:
To inform the public.
Description:
Nitrogen (N) retention in stream networks is an important ecosystem service that may be affected by the widespread burial of headwater streams in urban basins. Urban stream burial has only recently been recognized by ecologists and little research has addressed the extent to which burial may affect N retention. We measured nitrate (NO3-) removal rates using whole stream 15NO3- isotope tracer releases in buried and day-lighted reaches of three streams in Cincinnati, Ohio (USA) during three seasons. During the summer, NO3- uptake lengths in buried reaches (2029 – 8581m) were a factor of 3-23 greater than day-lighted reaches (88 – 2952m), which is partially attributable to differences in water velocities (buried= 4.6m/s, day-lighted=1.3m/s). The artificial stream bottoms in the buried reaches supported heterotrophic biofilms (standing stocks=10.2, 8.4, 0.45 gAFDM/m2), but had lower detrital organic matter standing stocks and ecosystem respiration rates than day-lighted reaches (p<0.04). Our results suggest the combined effects of elevated water velocity and reduced biological activity in buried reaches inhibits NO3- retention, exacerbating the export of excess N to downstream water bodies.