SFS Annual Meeting

5/23/2019  |   14:00 - 14:15   |  251 DE

ABUNDANCE AND DISTRIBUTION OF LAKES ACROSS CALIFORNIA’S SIERRA NEVADA Small lakes play a disproportionate role in energy flow and the processing of materials at all scales. California’s Sierra Nevada mountain range provides opportunities for testing the applicability of existing limnological conceptual frameworks developed in certain lake-rich regions to other parts of the world. Using remotely-sensed regional mountain lake data from USGS and other global-scale datasets, we pursued a census of all lakes in California’s Sierra Nevada mountain range. Our goal was to develop a comparison of frequency-size (and other) distributions for Sierra lakes to other lake-rich regions of the world. Preliminary analyses show that of 11,667 lakes >2300 m elevation, 57% of lakes are small (<0.002 km^2); expressing a right-skewed distribution. While these results mirror other regions, we hypothesize that distributions differ from other lake-rich regions in unique ways that make it an excellent model system for testing landscape limnological theory. Ultimately, our case study provides applicable information that can be used in translational ecology towards improved and actionable conservation.

Christine Parisek (Primary Presenter/Author), University of California, Davis, cparisek@csustan.edu;


Steve Sadro (Co-Presenter/Co-Author), University of California, Davis, ssadro@ucdavis.edu;


Andrew Rypel (Co-Presenter/Co-Author), University of California-Davis, andrewrypel@gmail.com;


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5/23/2019  |   14:15 - 14:30   |  251 DE

QUANTIFYING HYPORHEIC FLOW IN BEAVER PONDS OF VARYING SIZE AND STREAM MORPHOLOGY Mountain desert ecosystems tend to have intermittent surface water flows. Driven by snowpack melt, these low-order streams lose the majority of their water by the late summer months. Since the reintroduction of beavers (Castor canadensis), surface water is able to remain year round due to a beaver dams ability to slow water velocity and impound water. This results in an increase of water retention time allowing for a greater hyporheic zone and surface to ground water interaction. In theory, beaver ponds of larger sizes should have an increased surface to ground water interaction relative to ponds of smaller size. To test this hypothesis and quantify seepage flux in beaver ponds, 18 seepage meters were placed along 6 beaver ponds of differing area and stream morphology. Sediment samples were taken from each pond and analyzed for particle size, bulk density/porosity, and sediment organic matter. Surface to ground water interactions had a positive relationship with pond size. This supports the hypothesis that beaver dams noticeably affect the interaction of surface and ground water in low-order desert streams. Additionally, there was an observed trend for decreasing groundwater infiltration with decreasing elevation.

Colton Sanders (Primary Presenter/Author), Murray State University, csanders17@murraystate.edu;


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5/23/2019  |   14:30 - 14:45   |  251 DE

ASSESSMENT OF THE FORMATION CRITERIA FOR HYPORHEIC ANOXIC MICROZONES WITH COMPUTATIONAL MODELING: INTERACTIONS OF HYDRAULICS, NUTRIENTS, AND BIOCLOGGING Experimental studies have detected ‘microzones’ in hyporheic zones, which form as small-scale anoxic pores volumes and biofilms embedded within oxygen-rich porous media. Microzones are anaerobic reaction sites where conditions promote production of reduction compounds such as nitrous oxide, a potent greenhouse gas. Microbes are a key control on nutrient transformation within sediments, yet microbial growth is also capable of limiting hydraulic flux in sediment, leading to potential ‘bioclogging.’ These microzone processes are difficult to detect and monitor in the field. Hence, we developed one of the first computational modeling approaches that combines hydraulic and microbial conditions to explore the presence of hyporheic microzones. We used the model to explore sediment conditions with different hydraulic flux, nutrient concentrations, and bioclogging scenarios. Results indicate that microzone formation is controlled by interactions between hydraulic flux, ambient nutrient concentrations, and bioclogging, with bioclogging strongly inhibiting stable microzone formation. Bioclogging scenarios typically produced unstable microzones, which perished a few days after formation. Overall, results show that bioclogging-induced anoxic microzones are likely to form under many realistic hyporheic conditions, but their distribution and biogeochemical function will be dynamic and difficult to measure in the field.

Sinchan Roy Chowdhury (Co-Presenter/Co-Author), Department of Earth and Environmental Sciences, Michigan State University, USA, sinchanrc90@gmail.com;


Mantha Phanikumar (Co-Presenter/Co-Author), Civil and Environmental Engineering, Michigan State University, phani@egr.msu.edu;


Martin Briggs (Co-Presenter/Co-Author), U. S. Geological Survey, Hydrogeophysics Branch, Storrs, Connecticut, USA, mbriggs@usgs.gov;


Fred Day-Lewis (Co-Presenter/Co-Author), U. S. Geological Survey, Hydrogeophysics Branch, Storrs, Connecticut, USA, daylewis@usgs.gov;


Kamini Singha (Co-Presenter/Co-Author), Department of Geology and Geological Engineering, Colorado School of Mines, Golden, CO, USA, ksingha@mines.edu;


Jay Zarnetske (Primary Presenter/Author), Department of Earth and Environmental Sciences, Michigan State University, jpz@msu.edu;


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5/23/2019  |   14:45 - 15:00   |  251 DE

GROUNDWATER FLUXES AS A DRIVER OF SPATIAL PATTERNS OF ECOLOGICAL FUNCTION AND STRUCTURE IN A HEADWATER STREAM NETWORK Fluxes of groundwater to stream ecosystems can influence physicochemical parameters, such as nutrients and temperature that are key drivers of ecological condition. However, the potential for groundwater to influence spatial patterns of ecological condition within a stream network is not well known. We present a multi-reach study assessing concordance of network scale patterns of groundwater influence and indicators of ecological function (decomposition and algal growth rate) and structure (algal biomass) during summer and winter baseflow conditions. The relative influence of groundwater was assessed using stream gaging radon concentration and stream temperature data from 19 reaches within the headwaters of a Thames River tributary in Ontario, Canada. Nutrient availability and its relationship with groundwater influence will also be evaluated. Algal communities were sampled by deploying artificial substrates in riffle, run and pool habitats of each sampling reach. Decomposition was assessed using the cotton strip assay. Spatial patterns of groundwater influence and ecological condition will be determined and correlations between proxies for groundwater influence and ecological conditions assessed for summer and winter samplings. Findings will improve understanding of the role of groundwater fluxes as a driver of spatial heterogeneity in-stream ecological conditions.

Adam G. Yates (Primary Presenter/Author), Western University & Canadian Rivers Institute, adam.yates@uwo.ca;


Shayla Kroeze (Co-Presenter/Co-Author), Western University & Canadian Rivers Institute, skroeze@uwo.ca;


Nicole Gotkowski (Co-Presenter/Co-Author), Western University & Canadian Rivers Institute, ngotkows@uwo.ca;


Max Boreux (Co-Presenter/Co-Author), Western University, mboreux@uwo.ca;


Jim Roy (Co-Presenter/Co-Author), Environment and Climate Change Canada, jim.roy@canada.ca;


Clare Robinson (Co-Presenter/Co-Author), Western University, crobinson@uwo.ca;


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