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SFS Annual Meeting

Monday, May 21, 2018
09:00 - 10:30

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09:00 - 09:15: / 310 B TRADE-OFFS AND CO-BENEFITS OF FUTURE FLOW REGIMES ACROSS MAJOR TAXONOMIC GROUPS

5/21/2018  |   09:00 - 09:15   |  310 B

TRADE-OFFS AND CO-BENEFITS OF FUTURE FLOW REGIMES ACROSS MAJOR TAXONOMIC GROUPS We highlight the antagonistic vs. synergistic effects of target-oriented flow management, and argue that mechanistic models provide useful tools for understanding river dynamics under uncertain futures. We developed three independent community-wide flow-population models for riparian plants, fish, and benthic invertebrates for use with a single flow regime. These models, which mechanistically link river flows with population dynamics, demonstrated the central importance of natural cycles of flooding and drought for the maintenance of healthy communities. Here, we demonstrate how these models can be employed to understand the effects of diverse future flow regimes across river ecosystems and the various trade-offs associated with managing flows for specific goals (e.g. natural flow mimicry, targeting native fish abundance) compared to business-as-usual (e.g. flow homogenization, climate change). By simultaneously examining multiple scenarios across three major taxonomic groups, we explore ways that flow regimes can be optimized to minimize the ecosystem-wide ecological deficit of designer flows. Different frequencies of response to flows among taxa provides unique challenges when setting out to optimize flows, but mechanistic models allow for robust forecasting of possible flow-regime futures.

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


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


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


Jane Rogosch (Co-Presenter/Co-Author), University of Washington, jfencl@uw.edu;


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


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


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09:15 - 09:30: / 310 B USING STOCHASTIC STATE-AND-TRANSITION MODELS TO EXPLORE POPULATION RESPONSES TO DROUGHT CYCLES.

5/21/2018  |   09:15 - 09:30   |  310 B

USING STOCHASTIC STATE-AND-TRANSITION MODELS TO EXPLORE POPULATION RESPONSES TO DROUGHT CYCLES. Climate variability and change pose significant threats to aquatic biodiversity, particularly in areas with low and variable runoff. Quantifying the magnitude of risk from these threats is made more difficult by the variable responses of individual species to hydrologic stress. For example, patterns of population decline and recovery in response to drought cycles will depend on both the resistance traits (e.g. tolerance to harsh environmental conditions) and resilience traits (e.g. fecundity, age at maturity). Collectively these traits can give rise to varied, and lagged patterns of decline and recovery in response to hydrologic variability, which ultimately can affect population viability in drought prone environments. Such population cycles are typically modelled based on demographic rates (mortality and recruitment) under different climate conditions. However, such models are relatively data hungry, limiting their widespread development. A less precise but more tractable approach is to adopt state-and-transition approaches based on semi-quantitative population states (or population size estimates), and modelled transitions between states under different hydrologic conditions. Here we demonstrate the application of such models to a suite of diverse taxa, highlighting the large uncertainties that can arise when taking into account stochastic state-transitions.

Avril Horne (Co-Presenter/Co-Author), The University of Melbourne, avril.horne@unimelb.edu.au;


Nick Bond (Primary Presenter/Author), Murray-Darling Freshwater Research Centre, La Trobe University, n.bond@latrobe.edu.au;


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09:30 - 09:45: / 310 B PREDICTING ENVIRONMENTAL TRAJECTORIES OF CHANGE UNDER A VARIABLE AND UNCERTAIN FUTURE

5/21/2018  |   09:30 - 09:45   |  310 B

PREDICTING ENVIRONMENTAL TRAJECTORIES OF CHANGE UNDER A VARIABLE AND UNCERTAIN FUTURE In Australia's Murray-Darling Basin, consumptive water use together with large variability in annual river flows has often resulted in declines in environmental condition in many river systems. The Murray-Darling Basin Plan establishes a policy mechanism to improve environmental outcomes through the recovery of water to be used for environmental purposes. Understanding how to best use this environmental water, as well as how environmental condition is tracking towards Basin Plan targets requires both understanding how environmental condition changes through time, and by having a probabilistic view of possible future flow conditions. Trajectory modelling aims to address these needs by forecasting a plausible range of environmental outcomes into the future. Recent advances in ecological modelling approaches used within the Basin, including the development of methods that link temporal sequencing of flow events to environmental change, facilitate the modelling of environmental trajectories. The aim of the trajectories project under the MDBA-CSIRO Eco-hydrology partnership is to develop a modelling approach to predict spatial and temporal trajectories of ecological change as a result of water management and climate variability.

Danial Stratford (Primary Presenter/Author), CSIRO, Danial.Stratford@csiro.au;


Peter Bridgeman (Co-Presenter/Co-Author), Murray-Darling Basin Authority, peter.bridgeman@mdba.gov.au;


Susan Cuddy (Co-Presenter/Co-Author), CSIRO, susan.cuddy@csiro.au;


Andrew Freebairn (Co-Presenter/Co-Author), CSIRO, andrew.freebairn;


Darran King (Co-Presenter/Co-Author), CSIRO, darran.king@csiro.au;


Mitchell Korda (Co-Presenter/Co-Author), CSIRO, mitchell.korda@csiro.au;


Rebecca Lester (Co-Presenter/Co-Author), Deakin University, rebecca.lester@deakin.edu.au;


Sam Nicol (Co-Presenter/Co-Author), CSIRO, sam.nicol@csiro.au;


Carmel Pollino (Co-Presenter/Co-Author), CSIRO Land and Water, Carmel.Pollino@csiro.au;


David Stevens (Co-Presenter/Co-Author), Murray-Darling Basin Authority, david.stevens@mdba.gov.au;


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09:45 - 10:00: / 310 B REDUCING THE DIMENSIONALITY OF SPECIES DIVERSITY WITH FLOW RESPONSE GUILDS AND GENETIC TRAIT SYNDROMES

5/21/2018  |   09:45 - 10:00   |  310 B

REDUCING THE DIMENSIONALITY OF SPECIES DIVERSITY WITH FLOW RESPONSE GUILDS AND GENETIC TRAIT SYNDROMES Biologists revel in the biodiversity of the world, but biodiversity can be a headache for management. How do we manage ecosystems that contain a diverse array of species, potentially with conflicting management needs? This study explores how traits can simplify diverse communities into groups that respond similarly to river flows and groups that have characteristic landscape genetic patterns. Flow-response traits were used to simplify diverse riparian plant communities into five guilds, and vegetation response was modeled under a variety of flow management scenarios. The model predicted high diversity and healthy community structure under natural flow regime, but loss of diversity with increasing drought or flood removal. To explore traits and genetic structure, landscape genetic patterns were characterized for three aquatic insects that spanned a diversity of ecohydrologic trait states. The three species had distinct landscape genetic patterns including nearly-complete isolation, to isolation-by-distance, and total panmixia. These distinct genetic trait syndromes lead logically to different management practices, with spatial connectivity benefitting some species but potentially harming others.

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


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10:00 - 10:15: / 310 B THE UTILITY OF SIMULATIONS IN UNDERSTANDING POPULATION DYNAMICS IN FRESH WATERS: EVALUATING DEMOGRAPHY, GENETICS, AND REINTRODUCTION OF A THREATENED CHAR

5/21/2018  |   10:00 - 10:15   |  310 B

THE UTILITY OF SIMULATIONS IN UNDERSTANDING POPULATION DYNAMICS IN FRESH WATERS: EVALUATING DEMOGRAPHY, GENETICS, AND REINTRODUCTION OF A THREATENED CHAR Modeling population dynamics of freshwater organisms is a complex challenge that often depends upon a combination of environmental, demographic, and genetic factors. Simulation-based approaches offer a promising way to address this challenge. We report results from a simulation study of bull trout (Salvelinus confluentus) reintroduction to three watersheds in northeastern Washington State, USA, where local extirpations of bull trout are linked to barriers, habitat degradation, invasive species and other factors. We used an individual-based, spatially-explicit simulation platform to evaluate how reintroduction strategies, life history variation, and environmental factors interact to influence the demography and population genetics of reintroduced bull trout populations. We found that connectivity (presence or absence of barriers) had the largest effect on demographic and genetic outcomes over 200 years, with a greater effect than both initial genetic diversity and life history variation. We also identified regions of the study system (e.g., the upper Sullivan watershed) in which bull trout populations persisted across a wide range of demographic, life history, and environmental parameters. Our results highlight the utility of simulation-based approaches in exploring and understanding population dynamics – and their implications for management strategies – in fresh waters.

Meryl Mims (Primary Presenter/Author), Virginia Tech, mims@vt.edu;


Andrew Bearlin (Co-Presenter/Co-Author), Seattle City Light, andrew.bearlin@gmail.com;


Jacob Burkhart (Co-Presenter/Co-Author), University of Missouri, jacob.burkhart9@gmail.com;


Casey Day (Co-Presenter/Co-Author), Purdue University, day29@purdue.edu;


Matthew Fuller (Co-Presenter/Co-Author), Duke University, matthew.robert.fuller@gmail.com;


Jameson Hinkle (Co-Presenter/Co-Author), University of Virginia, hinkyisme@gmail.com;


Erin Landguth (Co-Presenter/Co-Author), University of Montana, erin.landguth@gmail.com;


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10:15 - 10:30: / 310 B CONTRIBUTION OF "SEED BANKS" TO BACTERIOPLANKTON COMMUNITY DYNAMICS

5/21/2018  |   10:15 - 10:30   |  310 B

CONTRIBUTION OF "SEED BANKS" TO BACTERIOPLANKTON COMMUNITY DYNAMICS Many aquatic species contend with fluctuations in their environment by engaging in dormancy, a reversible state of reduced metabolic activity. In addition to buffering against harsh environmental conditions, dormancy generates a "seed bank" that maintains diversity and influences community dynamics. We tracked microbial communities in a southern Indiana lake for 2.5 years by sequencing the 16S rRNA gene (DNA) and transcripts (RNA). Because it is an ephemeral molecule that is essential for protein synthesis, we treat RNA as a proxy for metabolically "active" taxa, while DNA sequences reflect the "total" community consisting of taxa that are either active or dormant. We found that the active bacterial community was highly seasonal and predictable, while the inactive and transient subsets of the community displayed weaker seasonal trends. Taxa responded to seasonal environmental variation in different ways, with some taxa showing more predictable population dynamics than others. We also found evidence that persistently rare species may be regulated by strong negative frequency dependence. Overall, our results suggest that bacterioplankton dynamics track environmental variability closely, which may be aided by a potentially dynamic microbial seed bank.

Nathan Wisnoski (Primary Presenter/Author), Indiana University, wisnoski@indiana.edu;


Jay Lennon (Co-Presenter/Co-Author), Indiana University, lennonj@indiana.edu;


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