Baltimore Ecosystem Study Institute of Ecosystem Studies

2016 BES Annual Meeting Presentation and Poster Abstracts

Biogeochemical Symptoms of the Urban Stream Syndrome: Evidence from multiple scales of investigation
Reisinger, Alexander
Co-Authors: Emma J. Rosi-Marshall*, Peter M. Groffman, Thomas R. Dooy, and Sujay S. Kaushal *Dr. Rosi-Marshall will be presenting the talk for me as I am unable to attend the meeting

Abstract: Urbanization causes multiple alterations to the landscape, which in turn change physicochemical and biological properties of urban streams. These landscape changes include altered lithology (e.g., asphalt, concrete), leaky sewage infrastructure, and other human activities (road salt, fertilizer, industrial processes, etc.), leading to a multitude of physicochemical stressors ever-present in urban streams. We used multiple lines of inquiry to establish the chemical stressors occurring in urban streams and the consequences of these stressors on stream ecosystem functioning. First, we used long-term BES monitoring data to establish chemical fingerprints of streams within BES. Next, we performed a meta-analysis to quantify ecosystem functioning in urban streams. Finally, we used empirical field studies to quantify whole-stream metabolism and nitrogen (N) uptake across a range of restored and unrestored streams throughout Baltimore. Using these multiple lines of inquiry, we found that urban streams are highly bioreactive despite the multitude of physicochemical stressors associated with the urban stream syndrome. Our multivariate analysis of water quality across BES found that urban streams indeed exhibit a unique chemical fingerprint, largely driven by variation in chloride and sulfate. Despite these multiple chemical stressors, N dynamics in urban streams were comparable to reference streams, and our empirical work found the highest demand for N at an unrestored, concrete lined channel. Our results suggest that urban streams may be more resistant to physicochemical stress than reference ecosystems, or simply that the low biodiversity commonly associated with the urban stream syndrome does not equate to similar low rates of ecosystem functioning.