SFS Annual Meeting

5/24/2018  |   14:00 - 14:15   |  310 B

ASSESSING THE STATE OF FRESHWATER ECOSYSTEMS AT THE CATCHMENT SCALE TO SUPPORT THE ENVIRONMENTAL MANAGEMENT OF RIVERS Most freshwater ecosystems are confronted with multiple anthropogenic impairments at the same time. This calls for comprehensive management strategies to counteract, or even prevent, long-term impacts on habitats and their biodiversity, as well as on their ecological functions and services. Nevertheless, most ecological assessments are designed to determine the state of single sites, or single stream reaches. This information is insufficient to capture the condition of an entire river system and may mislead environmental managers and conservation practitioners in their decision making. We present an approach to describe the state of entire catchments using decision support methods, based on surveyed morphological and modeled nutrient data on the reach scale. For this purpose, we developed a set of spatial criteria summarizing the existing information based on the concept of ecological resilience in a spatially explicit way. The results of our approach are compared to data currently available for decision making, such as point based biotic indicators for benthic macroinvertebrates. The potential applications of the proposed approach are discussed, particularly for supporting the strategic planning and spatial prioritization of restoration measures.

Mathias Kuemmerlen (Primary Presenter/Author), Eawag, mathias.kuemmerlen@eawag.ch;


Diana van Dijk (Co-Presenter/Co-Author), Eawag, 'diana_van_dijk@yahoo.com';


Rosi Siber (Co-Presenter/Co-Author), Eawag, Rosi.Siber@eawag.ch;


Nele Schuwirth (Co-Presenter/Co-Author), Eawag, Nele.Schuwirth@eawag.ch;


Peter Reichert (Co-Presenter/Co-Author), Eawag, Peter.Reichert@eawag.ch;


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5/24/2018  |   14:15 - 14:30   |  310 B

BEYOND “DONORS AND RECIPIENTS”: IMPACTS OF SPECIES GAINS AND LOSSES REVERBERATE AMONG ECOSYSTEMS DUE TO CHANGES IN RESOURCE SUBSIDIES Pervasive environmental degradation has altered biodiversity at a global scale. At smaller scales, species extirpations, invasions, and replacements have greatly influenced how ecosystems interact by affecting the exchanges of energy, materials, and organisms. We examined how species losses and gains affect the exchange of resources (materials and/or organisms) within and among ecosystems. We specifically consider how changes that occur within an ecosystem may trigger effects that reverberate (e.g., directly, indirectly, via feedbacks) back and forth across ecological boundaries and propagate to multiple habitats or ecosystems connected via exchange of materials and organisms. Our synthesis provides a cursory overview of ‘openness’ as it has been addressed by community ecologists and then we briefly characterize the conceptual development ecological frameworks used to examine resource exchanges between ecosystems. We then describe multiple case-studies and examine how species losses and gains affect food web structure via resource exchanges between ecosystems, with particular emphasis on effects spanning land-water boundaries.

Scott Collins (Primary Presenter/Author,Co-Presenter/Co-Author), Texas Tech University, Scott.Collins@ttu.edu;


Colden Baxter (Co-Presenter/Co-Author), Idaho State University, baxtcold@isu.edu;


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5/24/2018  |   14:30 - 14:45   |  310 B

WINTER PRECIPITATION AND SUMMER TEMPERATURE PREDICT LAKE ECOSYSTEM PROPERTIES AT MACROSCALES Climate change can have strong effects on aquatic ecosystems, including disrupting nutrient cycling and mediating processes that affect primary production. However, because past studies have been conducted mostly on individual or small groups of ecosystems, it is challenging to predict how future climate change will affect ecosystem processes at broad spatial scales. We used climate metrics to predict lake ecosystem properties related to nutrient concentrations and primary production in ~11,000 north temperate lakes across broad gradients in climate and ecological context using a novel machine learning model. We found that climate metrics related to winter precipitation and summer temperature were strong predictors of lake nutrients and productivity, but that there was variation in the magnitude and direction of the relationship between climate metrics and lake ecosystem properties. Our results predict that future climate change scenarios of increased summer temperatures will lead to variable but positive effects in nutrients or algal biomass across lakes but that increased winter precipitation will have more neutral but highly variable effects. These findings emphasize the importance of heterogeneity in the response of individual ecosystems to climate, and are a caution to extrapolating responses across space.

Sarah M Collins (Primary Presenter/Author), University of Wyoming, sarah.collins@uwyo.edu;


Shuai Yuan (Co-Presenter/Co-Author), Michigan State University, yuanshu2@msu.edu;


Pang-Ning Tan (Co-Presenter/Co-Author), Michigan State University, ptan@cse.msu.edu;


Samantha Oliver (Co-Presenter/Co-Author), United States Geological Survey, oliver.samanthak@gmail.com ;


Jean Francois Lapierre (Co-Presenter/Co-Author), University of Montreal, jfrancoislapierre@gmail.com;


Kendra Cheruvelil (Co-Presenter/Co-Author), Michigan State University, ksc@msu.edu;


C. Emi Fergus (Co-Presenter/Co-Author), The National Research Council, emifergus@gmail.com;


Nicholas Skaff (Co-Presenter/Co-Author), University of California, Berkeley, nicholas.skaff@gmail.com;


Joseph Stachelek (Co-Presenter/Co-Author), Michigan State University, stachel2@msu.edu;


Tyler Wagner (Co-Presenter/Co-Author), U.S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, txw19@psu.edu;


Patricia A Soranno (Co-Presenter/Co-Author), Michigan State University, soranno@anr.msu.edu;


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5/24/2018  |   14:45 - 15:00   |  310 B

COMPARING SPATIAL PATTERNS OF RIVER WATER ISOTOPES ACROSS NETWORKS A detailed understanding of the spatial and temporal dynamics of water sources across river networks is central to managing the impacts of climate change. Because the stable isotope composition of precipitation varies geographically, variation in surface-water isotope signatures indicates the volume-weighted integration of upstream source water. We measured the isotope composition of surface-water samples collected during summer low-flow across five basins in the Pacific Northwest and SE Alaska (Snoqualmie, Green, Wenatchee, and Skagit Rivers, and Cowee Creek) to examine spatial variation in surface-water isotopes across a range of hydraulic and climatic conditions. We found mean catchment elevation correlated with surface-water isotopic signatures on the west side of the Cascades and Alaska, explaining 41-92% of variation. Conversely, in the Wenatchee, elevation of the catchment had no predicative power. For this basin we built an alternative model to explain the spatial distribution of isotopic variation and compare it to previously published work in the Marys River. In the Snoqualmie, where elevation explained the highest proportion of isotopic variation, we compare isotopic signatures across the network between early and late summer to explore the spatial distribution of residual snowmelt.

E. Ashley Steel (Co-Presenter/Co-Author), PNW Research Station, US Forest Service, asteel@fs.fed.us;


J. Renee Brooks (Co-Presenter/Co-Author), EPA Western Ecology Division, Brooks.Reneej@epa.gov ;


Lillian McGill (Primary Presenter/Author), University of Washington , lmcgill@uw.edu;


Aimee Fullerton (Co-Presenter/Co-Author), Northwest Fisheries Science Center, NOAA, aimee.fullerton@noaa.gov;


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5/24/2018  |   15:00 - 15:15   |  310 B

A STATISTICAL MIXING MODEL PREDICTS NETWORK-SCALE TEMPERATURE PATTERNS IN STREAMS WITH ABUNDANT ALPINE LAKES Streams often display a longitudinal trend in stream temperature along elevational gradients. However, atmospheric heat exchange in alpine lakes differs substantially from that of alpine streams. Thus, lake-outlet streams contribute spatial variation in stream temperature across montane stream networks, yielding complex longitudinal temperature patterns that deviate from the expected monotonic trends. We developed a GIS-based metric of lake influence and incorporated the metric into a statistical mixing model to disentangle and characterize alpine-lake and elevation effects on stream temperature in the North St. Vrain stream network in Rocky Mountain National Park, Colorado, USA. Relative to more conventional multiple linear regression approaches, our method yielded a marked increase in explanatory power for daily mean stream temperature across a stream network with abundant alpine lakes. As a mixing model, our method may be applicable to any system where network-scale patterns in stream temperature arises from spatially variable influences of multiple water sources that have distinct thermal regimes.

Geoffrey Poole (Primary Presenter/Author), Montana State University, Montana Institute on Ecosystems, gpoole@montana.edu ;


Sam Carlson (Co-Presenter/Co-Author), Montana State University, sam.p.carlson@gmail.com;


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5/24/2018  |   15:15 - 15:30   |  310 B

DISTURBANCE IN A STREAM NETWORK: GENETIC AND DEMOGRAPHIC DATA HELP PREDICT POST-DISTURBANCE COMMUNITY STRUCTURE Stream networks can experience extreme disturbances that alter community structure. Properties of both the network and species that reside there are thought to influence community response, including recovery rates. A genetic monitoring approach was used to characterize responses of the fish community to disturbance resulting from a series of three catastrophic wildfires in a dryland stream network. Three of eight species exhibited declines in genetic diversity and lowered effective population sizes (Ne) in response to wildfires, whereas other species exhibited no changes. Temporal genetic sampling revealed synergy between changes in allele frequencies and species-specific demographic parameters. By comparing temporal changes in genetic diversity and structure spanning pre-disturbance through recovery phases, we developed a conceptual framework that makes explicit predictions concerning the trajectory of genetic summary statistics in response to disturbance. Applying our framework across species revealed differences in relative roles of dispersal and local compensatory reproduction to resilience and recovery following intense disturbance. Integration across species helps predict post-disturbance community structure.

Thomas Turner (Primary Presenter/Author), University of New Mexico, turnert@unm.edu;


Tyler Pilger (Co-Presenter/Co-Author), FISHBIO, tjpilger@gmail.com;


Keith Gido (Co-Presenter/Co-Author), Kansas State University, kgido@ksu.edu;


David Propst (Co-Presenter/Co-Author), University of New Mexico, tiaroga@comcast.net;


James Whitney (Co-Presenter/Co-Author), Pittsburg State University, jewhitney@pittstate.edu;


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