Thursday, June 8, 2017
11:00 - 12:30

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11:00 - 11:15: / 302B DON'T DROWN IN THE DATA DELUGE: SUPPORTING THE ANALYSIS OF BIG FRESHWATER DATA

6/08/2017  |   11:00 - 11:15   |  302B

DON'T DROWN IN THE DATA DELUGE: SUPPORTING THE ANALYSIS OF BIG FRESHWATER DATA Data availability no longer limits many advances in freshwater science. Instead, researchers are challenged to efficiently wrangle, analyze, and share complex time-series data. For example, the StreamPULSE project is expanding the availability of stream metabolism predictions but we face multiple data challenges, including 1.) assimilation and homogenization from many sources, 2.) consistent quality checks, and 3.) network-wide data access and modeling. These issues are not unique to our project. Here we present an approach for managing these challenges with an open-source web-based software stack that we have developed. We use this software to easily preview time-series data, rapidly flag problem data with machine learning, and download data and model output. We outline how these tools help us analyze the data from our network and discuss how they can be useful to researchers with similar challenges.

Aaron Berdanier (Primary Presenter/Author), Duke University, aaron.berdanier@gmail.com;


StreamPULSE Network ( Co-Presenter/Co-Author), Multiple Institutions, abb30@duke.edu;


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11:15 - 11:30: / 302B FLOW REGIME ALTERATION DEGRADES ECOLOGICAL NETWORKS IN RIVERINE ECOSYSTEMS

6/08/2017  |   11:15 - 11:30   |  302B

FLOW REGIME ALTERATION DEGRADES ECOLOGICAL NETWORKS IN RIVERINE ECOSYSTEMS Riverine ecosystems are governed by patterns of temporal variation in river flows. This dynamism is threatened by climate change and the near-ubiquitous human control of river flows globally, which may have severe effects on species distributions and interactions. There is therefore a fundamental need to forecast riverine ecosystem responses to changing flow regimes over long timescales. We employed a combination of population modeling and network theory to explore the consequences of possible flow regime futures on riparian plant communities in the American Southwest, including scenarios of increased drought, flooding, and flow homogenization. We show that even slight modifications to the natural flow regime can have severe consequences for the structure of riparian plant networks. Networks of emergent interactions were most dense at the natural flow regime and became simplified as a function of flow alteration. The most influential component of flow alteration was flood reduction, with drought and flow homogenization both having greater negative community-wide consequences than increased flooding. Maintaining floods under future climates will be needed to overcome the negative long-term consequences of flow modification on riverine ecosystems.

Jonathan Tonkin (Primary Presenter/Author), Oregon State University, jdtonkin@gmail.com;


David Merritt ( Co-Presenter/Co-Author), USDA Forest Service, dmmerritt@fs.fed.us;


Julian Olden ( Co-Presenter/Co-Author), University of Washington, Seattle, olden@uw.edu;


Lindsay Reynolds ( Co-Presenter/Co-Author), USDA Forest Service, lindsayreynolds@fs.fed.us;


David Lytle ( Co-Presenter/Co-Author), Oregon State University, lytleda@oregonstate.edu;


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11:30 - 11:45: / 302B FOREST RESILIENCY - WHAT IS AT RISK IN TERMS OF FOREST WATER SUPPLIES IN THE ANTHROPOCENE?

6/08/2017  |   11:30 - 11:45   |  302B

Forest Resiliency - What Is At Risk In Terms Of Forest Water Supplies In The Anthropocene? Forests serve crucial roles in regulating freshwater resources. When complex global change drivers interact with the equally complex structure of natural forest ecosystems, uncertainty is created as forests change in structure and function. Within a climate-modified forest stream, not all measurable ecological processes change in lockstep – some signals change quickly and may intiate a cascading sequence of changes. These changes are expected to occur at a higher rate in northern latitude forests. The following question was considered: Is there empirical evidence of climate change driving forest waters into a “new normal”? First, multivariate autoregressive models were applied to a cluster of forested watersheds to explore the interactive effects of climate change on hydrological and biogeochemical resiliency (reactivity and recovery rates). Second, indicators of shifts to alternative stable states were explored to identify which hydrological and biogeochemical constituents were driving loss of resiliency. Forests without wetlands showed higher reactivity but lower recovery rates in hydrological and biogeochemical exports. Forests without wetlands appear to be moving into a “new normal” defined by increased nitrogen (but decreased phosphorus) export to surface waters, with human-modified forested systems (e.g., managed forests) accelerating these changes.

Irena Creed (Primary Presenter/Author), Western University, icreed@uwo.ca;
Irena Frances Creed is a Professor and Canada Research Chair in Watershed Sciences at Western University in Canada. Her research leadership and activity have improved our understanding of watershed hydrological and biogeochemical functions under present and predicted climate scenarios. By coupling this understanding with innovative techniques in geographic information systems, remote sensing and modeling to characterize these functions, she has enabled governments to develop planning and regulatory tools in support of innovative policies designed to ensure the sustainability of watershed systems.

Mark Scheuerell ( Co-Presenter/Co-Author), NOAA Northwest Fisheries Science Center, mark.scheuerell@noaa.gov;


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11:45 - 12:00: / 302B QUANTIFYING CHANGES IN THE LENGTH OF THE GROWING SEASON IN MOUNTAIN STREAMS BASED ON OBJECTIVE EVALUATIONS OF TRENDS IN HYDROLOGIC REGIMES (SIZER)

6/08/2017  |   11:45 - 12:00   |  302B

QUANTIFYING CHANGES IN THE LENGTH OF THE GROWING SEASON IN MOUNTAIN STREAMS BASED ON OBJECTIVE EVALUATIONS OF TRENDS IN HYDROLOGIC REGIMES (SIZER) Climate change is expected to generate earlier peak flows in snowmelt driven hydrologic systems. Earlier snowmelt may lengthen the algal growing season, altering the annual cycles of aquatic biogeochemical processing. We used the “significant zero crossings” (SiZer) approach to evaluate hydrologic thresholds by computing the derivatives of smoothed hydrograph models. SiZer generates a range of models with different time scales of smoothing, providing a robust assessment of the statistical significance in the temporal trends of hydrograph inflections. We applied SiZer to quantify timing of peak flow and start of the baseflow recession in annual hydrographs for montane regions of the Gallatin River in southwest Montana (89-yr period of record). Our preliminary analysis evaluated a 15-year dataset to characterize recent variation in the start of the growing season. SiZer analysis affected interpretation of trends by eliminating the noise in the data generated by conventional analysis of multimodal hydrographs. This study provides an objective perspective on how high-elevation watersheds are responding to climate dynamics, and has implications to understanding an important causal link between climate change and metabolic biogeochemistry in mountain headwaters.

Meryl Storb (Primary Presenter/Author), Montana State University, meryl.storb@gmail.com;


Robert Payn ( Co-Presenter/Co-Author), Montana State University, Montana Institute on Ecosystems, rpayn@montana.edu;


Mark Greenwood ( Co-Presenter/Co-Author), Montana State University, greenwood@montana.edu ;


HongYi Li ( Co-Presenter/Co-Author), Montana State University, hongyi.li@montana.edu ;


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12:00 - 12:15: / 302B RESILIENCE OF AQUATIC FOOD CHAINS TO PRESS AND PULSE PERTURBATIONS

6/08/2017  |   12:00 - 12:15   |  302B

RESILIENCE OF AQUATIC FOOD CHAINS TO PRESS AND PULSE PERTURBATIONS Aquatic ecosystems are subject to myriad press and pulse perturbations including nutrient and sediment inputs, invasive species, floods, droughts, and increasing temperature. We sought to determine the attributes of ecosystems that confer resilience to perturbations, specifically the influence of interaction strength, fast and slow turnover pools, and ecosystem characteristics. We curated long-term data from lake and river ecosystems describing time series of nutrient concentrations, primary producers, consumers, and predators. We applied multivariate autoregressive state-space (MARSS) models to estimate metrics of resilience to perturbations, including reactivity of the ecosystem to perturbation and the return rate of the ecosystem following a perturbation. Since perturbations radiate through food chains in different ways, we explored the effect of top-down, bottom-up, and diffuse pathways of perturbation radiation through ecosystems. Our preliminary results indicate that riverine sediment inputs propagate through lake ecosystems following a variety of radiative models. Systems with high mean interaction strengths exhibited the greatest reactivity and return time. This meta-analysis of aquatic time series data contributes to our understanding of the factors shaping the resilience of aquatic ecosystems to disturbance.

James Hood (Primary Presenter/Author), The Ohio State University, hood.211@osu.edu;


Thomas Barnum ( Co-Presenter/Co-Author), Smithsonian Environmental Research Center, barnumt@si.edu;


Irena Creed ( Co-Presenter/Co-Author), Western University, icreed@uwo.ca;
Irena Frances Creed is a Professor and Canada Research Chair in Watershed Sciences at Western University in Canada. Her research leadership and activity have improved our understanding of watershed hydrological and biogeochemical functions under present and predicted climate scenarios. By coupling this understanding with innovative techniques in geographic information systems, remote sensing and modeling to characterize these functions, she has enabled governments to develop planning and regulatory tools in support of innovative policies designed to ensure the sustainability of watershed systems.

Shawn Devlin ( Co-Presenter/Co-Author), Flathead Lake Biological Station- University of Montana, shawn.devlin@umontana.edu;


Michelle Evans-White ( Co-Presenter/Co-Author), University of Arkansas, mevanswh@uark.edu;


Tamara Harms ( Co-Presenter/Co-Author), University of Alaska Fairbanks, tamara.harms@alaska.edu;


Jeremy Jones ( Co-Presenter/Co-Author), Univeristy of Alaska Fairbanks, jay.jones@alaska.edu;


Claire Ruffing ( Co-Presenter/Co-Author), University of Alaska Fairbanks, cmruffing@alaska.edu;


Albert Ruhi ( Co-Presenter/Co-Author), National Socio-Environmental Synthesis Center. , aruhi@sesync.org;


Mark Scheuerell ( Co-Presenter/Co-Author), NOAA Northwest Fisheries Science Center, mark.scheuerell@noaa.gov;


Adrianne Smits ( Co-Presenter/Co-Author), University of Washington, adriannesmits@gmail.com;


Tanner Williamson ( Co-Presenter/Co-Author), Miami University, tanner.williamson@gmail.com;


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12:15 - 12:30: / 302B STREAM PRODUCTIVITY DRIVES SHARP REDUCTIONS IN TEMPORAL BETA DIVERSITY OF MACROINVERTEBRATE ASSEMBLAGES

6/08/2017  |   12:15 - 12:30   |  302B

STREAM PRODUCTIVITY DRIVES SHARP REDUCTIONS IN TEMPORAL BETA DIVERSITY OF MACROINVERTEBRATE ASSEMBLAGES We examined benthic macroinvertebrate assemblages in 35 streams in Oklahoma and Arkansas, USA that spanned a steep gradient of nutrient enrichment to test the hypothesis that increases in productivity lead to more temporally homogenous communities. We collected quantitative benthic samples and measured physical and chemical variables from riffle habitats bimonthly for 2 yr. We computed both classical metrics and multivariate measures of temporal beta diversity (βt), coupled with a null model permutation procedure, to gain a degree of insight into the temporal assembly process. We utilized generalized linear modeling of βt within an iterative information-theoretic framework to examine the effect of productivity (measured as phosphorus enrichment and chlorophyll-a) and other contributing or confounding factors that influenced trends in βt. Model selection indicated that increases in both proxies of productivity drove declines in the patterns of seasonal succession of macroinvertebrate assemblages. Increases in total and snail biomass, as well as increased thermal variability, also corresponded to decreases and increases in βt, respectively. The manner in which the temporal partitioning of these communities declines has implications for both study design and biomonitoring.

Stephen Cook (Primary Presenter/Author), Baylor University, Stephen_Cook@baylor.edu;


Lauren Housley ( Co-Presenter/Co-Author), Baylor University, Lauren_Housley@baylor.edu;


Jeffrey A. Back ( Co-Presenter/Co-Author), Baylor University, Jeff_Back@baylor.edu;


Ryan S. King ( Co-Presenter/Co-Author), Baylor University, Ryan_S_King@ Baylor.edu;


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