5/18/2015  |   13:30 - 13:45   |  103AB

GLOBAL META-ANALYSIS OF TEMPERATURE EFFECT ON LEAF LITTER BREAKDOWN RATES IN STREAMS The response of leaf litter breakdown to elevated temperature in streams and rivers worldwide is uncertain given variation in macroinvertebrate responses to temperature and large differences in plant litter quality. Here, we synthesize 1025 records of leaf litter breakdown rates in streams and rivers, from 169 published studies, spanning latitudes of 0° to 60°, to quantify the apparent temperature dependence of leaf litter breakdown and examine how macroinvertebrate density and leaf quality affect this dependence. The global apparent activation energy of breakdown was 0.34 ± 0.04 eV, which was lower than the theoretically predicted value (~0.60 eV). This estimate was consistent for rates mediated by microbes alone and by microbes plus macroinvertebrates, contrary to previous research. Although activation energy varied across individual plant genera (n = 12), differences were not related to indicators of leaf quality. Our results suggest that rates of leaf litter breakdown may increase by 11-16% with a 2-3 °C average global increase in water temperature, but the balance of microbial and metazoan contributions to leaf litter processing is unlikely to change.

Jennifer Follstad Shah (Primary Presenter/Author), Utah State University, follstad@gmail.com;


John S. Kominoski (Co-Presenter/Co-Author), Florida International University, jkominoski@gmail.com;


Marcelo Ardon-Sayao (Co-Presenter/Co-Author), East Carolina University, ARDONSAYAOM@ecu.edu;


Walter Dodds (Co-Presenter/Co-Author), Kansas State University, wkdodds@ksu.edu;


Mark Gessner (Co-Presenter/Co-Author), Leibniz-Institute of Freshwater Ecology and Inland Fisheries / Berlin Institute of Technology , gessner@igb-berlin.de;


Natalie Griffiths (Co-Presenter/Co-Author), Oak Ridge National Laboratory, griffithsna@ornl.gov;


Sherri Johnson (Co-Presenter/Co-Author), U.S. Forest Service, Pacific Northwest Research Station, sherrijohnson@fs.fed.us;


Antoine Lecerf (Co-Presenter/Co-Author), EcoLab, Université de Toulouse, CNRS, France, antoine.lecerf@univ-tlse3.fr;


Carri LeRoy (Co-Presenter/Co-Author), Evergreen State College, leroyc@evergreen.edu;


David W.P. Manning (Co-Presenter/Co-Author), University of Georgia, manningd@uga.edu;


Amy D. Rosemond (Co-Presenter/Co-Author), University of Georgia, rosemond@uga.edu;


Chris Swan (Co-Presenter/Co-Author), University of Maryland-Baltimore County, chris.swan@umbc.edu;


Jack Webster (Co-Presenter/Co-Author), Virginia Polytechnic Institute and State University, jwebster@vt.edu;


Lydia Zeglin (Co-Presenter/Co-Author), Kansas State University, lzeglin@ksu.edu;

5/18/2015  |   13:45 - 14:00   |  103AB

MODELING OF STREAM MACROINVERTEBRATE COMMUNITIES UNDER CLIMATE CHANGE At the northernmost latitudes, air temperature is predicted to increase steeply by the end of the century. Precipitation and snow-fall are also predicted to change with potentially significant effects on flow regimes. In boreal regions, cold-water species may be unable to escape the novel thermal regime, and their distributions may be strongly affected. We used site-specific modeled air temperatures and hydrological indices together with five different climatic scenarios based on medium emissions to predict the future (2020 to 2100) benthic macroinvertebrate community composition at 240 sites across Finland. We used RIVPACS-type multi-taxon niche modelling to predict the present-day composition of macroinvertebrate communities and to evaluate potential future changes. The final model included six variables: air temperature and five hydrological indices related to different aspects of flow regime. The mean observed-to-expected (O/E) ratios decreased steadily throughout the century under all climatic scenarios. Compositional changes in macroinvertebrate taxa were predicted to be most extreme in the northernmost sites. These results indicate that currently used biomonitoring programs will need to be modified to accommodate climate-change induced alteration of stream biodiversity.

Kaisa-Riikka Mustonen (Primary Presenter/Author), Thule Institute, University of Oulu, Finland, kaisa.mustonen@oulu.fi;


Heikki Mykrä (Co-Presenter/Co-Author), Thule Institute, University of Oulu and Environment Centre of Finland, Oulu, Finland, heikki.mykra@oulu.fi;


Romain Sarremejane (Co-Presenter/Co-Author), Thule Institute, University of Oulu, Finland, romain.sarremejane@oulu.fi;


Charles Hawkins (Co-Presenter/Co-Author), Utah State University, chuck.hawkins@usu.edu;


Hannu Marttila (Co-Presenter/Co-Author), Water Resources and Environmental Engineering Research Group, University of Oulu, Finland, hannu.marttila@oulu.fi;


Timo Muotka (Co-Presenter/Co-Author), Ecology and Genetics Research Unit, University of Oulu, Finland, timo.muotka@oulu.fi;

5/18/2015  |   14:00 - 14:15   |  103AB

LONG-TERM (1978–2012) PATTERNS OF INSECT COMMUNITIES IN AN ARCTIC RIVER In response to rapidly rising temperatures due to the polar amplification of greenhouse warming, river ecosystems in the Arctic are expected to undergo significant change during this century. To provide insight into the potential consequences of these changes to aquatic communities, we assessed temporal patterns of insect life histories in the Kuparuk River in arctic Alaska. Sampling during the 2011 open-water season revealed the presence of a previously undocumented spring cohort for Cinygmula (Ephemeroptera). A selection of growth rates for the grazing mayfly Acentrella lapponica from 1986-2012 reveals no consistent change through time. Analysis of growth rate and abundance for A. lapponica collected in 2001, 2009-2012 show a strong correlation with epilithic nitrogen:phosphorus (r2>0.65). Abundance for Orthocladius rivulorum (Chironomidae) was strongly correlated with algal biomass over a 29-year period (r2=0.39). These data demonstrate that resource quality and/or quantity appear to be important factors for the dominant grazers in the Kuparuk River. This further emphasizes the importance of shoulder seasons to aquatic insect communities and suggests that factors other than temperature may be important components of community responses to climate change.

Michael Kendrick (Primary Presenter/Author), The University of Alabama, kendrickmr@gmail.com;


Anne Hershey (Co-Presenter/Co-Author), The University of North Carolina at Greensboro, aehershe@uncg.edu;


Alexander D Huryn (Co-Presenter/Co-Author), The University of Alabama, huryn@bama.ua.edu;

5/18/2015  |   14:15 - 14:30   |  103AB

ASSESSING AQUATIC INVERTEBRATES ALONG ELEVATION GRADIENTS IN GRAND TETON NATIONAL PARK, WYOMING High elevation ecosystems are predicted to be strongly impacted by climate change; however, little is known of the extant biodiversity in mountain streams and lakes. We sampled 5 streams and 6 lakes in Grand Teton National Park, Wyoming to establish a baseline of invertebrate assemblages and environmental conditions. We collected 5 surber samples from low, middle and high elevation sites along each stream. We collected nearly 10,000 individuals per meter square from streams, but the density (ANOVA, p=0.18) and richness (p=0.54) of invertebrates did not vary significantly by elevation. Invertebrate assemblages were more similar at low sites compared to high sites when plotted using non-metric multidimensional scaling. Total density of invertebrates was positively related to the amount of visible biofilm (AIC,p=0.03) and oxidation-reduction potential (p=0.05), and taxa richness was negatively related to specific conductivity (p=0.009). Littoral invertebrates were far less diverse in lakes (19 taxa) compared to streams (68 taxa). Our data may help target aquatic invertebrates to monitor as temperatures rise, and the biotic and abiotic factors that structure alpine aquatic ecosystems in Grand Teton National Park.

Lusha Tronstad (Primary Presenter/Author), University of Wyoming, Wyoming Natural Diversity Database, tronstad@uwyo.edu;


Scott Hotaling (Co-Presenter/Co-Author), Washington State University, scott.hotaling@uky.edu;


Cody Bish (Co-Presenter/Co-Author), Wyoming Game and Fish Department, jamescbish@gmail.com;

5/18/2015  |   14:30 - 14:45   |  103AB

POTENTIAL IMPACTS OF CLIMATE CHANGE ON REPRODUCTION AND DISPERSAL OF NATIVE ATYOIDA BISULCATA SHRIMP IN HAWAIIAN HEADWATER STREAMS Tropical streams are dominated by amphidromous shrimp, fish, and snails that require perennial flow from streams to nearshore environments to complete their lifecycles. Stream flow is also an important environmental cue for the hatching and dispersal of amphidromous larvae as well as the recruitment of postlarvae. Stream flow alterations from dams, diversions and anticipated rainfall declines from climate change threaten species persistence and overall stream function. Utilizing a model ecosystem on the North Hilo coast of Hawaii Island that spans a 4,500 mm/year rainfall gradient, while land use and other physical variables were held constant, we examined how decreased stream flow impacted larval dispersal of the endemic atyid shrimp, Atyoida bisulcata. In 2013 and 2014, average egg counts and development stage in gravid female shrimp were compared across nine streams with differing flows. Relative differences in larval dispersal across streams were examined using 24-hour drift samples. Preliminary results from 2013 revealed that egg counts were strongly, but not significantly correlated (r = 0.74; p=0.06) with stormflow (Q10). Results comparing egg counts and larval drift among streams will also be presented.

Charlie Yak (Co-Presenter/Co-Author), University of Papua New Guinea, aleifreddie@gmail.com;


Ralph Tingley (Co-Presenter/Co-Author), Missouri Cooperative Fish and Wildlife Research Unit, tingleyr@msu.edu;


Maybeleen Apwong (Co-Presenter/Co-Author), University of Hawaii at Hilo, am9@hawaii.edu;


James Akau (Co-Presenter/Co-Author), University of Hawaii at Hilo, jakau3@hawaii.edu;


Patra Foulk (Co-Presenter/Co-Author), USDA Forest Service, foulkpb@gmail.com;


Richard MacKenzie (Primary Presenter/Author), USDA Forest Service, rmackenzie@fs.fed.us;

5/18/2015  |   14:45 - 15:00   |  103AB

VULNERABILITY OF COASTAL CUTTHROAT TROUT TO CHANGES IN STREAM TEMPERATURE AND FLOW IN COASTAL STREAMS OF THE PACIFIC NORTHWEST OF NORTH AMERICA Climate change is affecting animals around the globe. Throughout the range of Coastal Cutthroat trout in western North America, stream temperature and flow are expected to become more variable leading to increases in uncertainty related to how they will influence trout. Here, we use a scenario-neutral approach to evaluate the sensitivity of Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) populations to a plausible range of gradual changes expressed as separate and combined effects of stream temperature and flow. We use an individual-based model heavily parameterized with field data of geophysical template, trout abundance, and environmental regimes collected in Coastal streams of California and Oregon. The model tracks individual trout through daily processes of spawning, movement, feeding, growth, and mortality for six decades. Our results show that stream-trout persist with extreme changes in temperature and flow, but with seriously reduced biomass. Minimal changes to stream temperature and flow lead populations to maintain or increase biomass. Our findings provide managers with enough information on trout responses to incorporate new climate change projections that may arise from new climate models when they are available.

Brooke Penaluna (Primary Presenter/Author), PNW Research Station, US Forest Service, brooke.penaluna@oregonstate.edu;