COS 63-7 - Experimental drought in eastern Sierra Nevada streams

Thursday, August 11, 2016: 9:50 AM
304, Ft Lauderdale Convention Center
Parsa Saffarinia1, Dave Herbst2, R. Bruce Medhurst2 and Kurt E. Anderson1, (1)Department of Biology, University of California, Riverside, Riverside, CA, (2)Sierra Nevada Aquatic Research Laboratory, University of California Santa Barbara, Mammoth Lakes, CA

Climate models project less precipitation and a shift in precipitation timing in the Sierra Nevada of California, with implications for the functioning of instream food webs. We experimentally induced flow reductions over two summers (2014-2015) in nine experimental stream channels at the Sierra Nevada Aquatic Research Laboratory (SNARL) to study how drought will affect stream food web, community and trait structure. Incremental flow reductions of baseline to intermittent drying were established in a press-type flow perturbation.


Channels with reduced flow showed decreasing discharge reduced total and EPT insect density, while DO and Chlorophyll-A appeared unaffected. Flow responses of insects appeared idiosyncratic across taxa and functional feeding groups. These results suggest that taxa-specific responses and life histories must be considered when examining responses to flow perturbation in montane streams.