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SFS Annual Meeting

Tuesday, May 21, 2019
14:00 - 15:30

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14:00 - 14:15: / 151 G HOW DOES STREAM DRYING INFLUENCE MACROINVERTEBRATE COMMUNITIES ACROSS CLIMATE GRADIENTS? A COMPARATIVE STUDY IN DESERT, GRASSLAND, AND FORESTED STREAMS

5/21/2019  |   14:00 - 14:15   |  151 G

HOW DOES STREAM DRYING INFLUENCE MACROINVERTEBRATE COMMUNITIES ACROSS CLIMATE GRADIENTS? A COMPARATIVE STUDY IN DESERT, GRASSLAND, AND FORESTED STREAMS Intermittent streams are extremely common in the contiguous United States, occurring in all terrestrial biomes. One might expect differences in how drying impacts stream communities across broad climate gradients due to predicted differences in drying duration and intensity in arid versus mesic climates. But cross-biome comparisons of how drying influences stream communities are scarce. We studied the impacts of drying on macroinvertebrate communities in three riverine systems across a broad climate gradient: a forested stream in southeastern Oklahoma; a grassland stream in northeastern Kansas, and a desert stream in central Arizona. Within each stream network, ten sites were chosen among 1st-4th order wadeable streams, with varying degrees of water permanence throughout the year. Sites were instrumented with a time-lapse camera system and stream temperature/conductivity sensors to gather data on surface water presence and flow state. Macroinvertebrates were collected quarterly at each site when surface water was present. Here we describe the summer results from this research project, integrating flow, temperature, and insect data to understand how stream benthic macroinvertebrate communities are shaped by stream drying patterns across broad spatial scales.

Daniel Nelson (Co-Presenter/Co-Author), University of Oklahoma, daniel.nelson79@gmail.com;


Steven Bittner (Co-Presenter/Co-Author), University of Oklahoma, stevenmbittner@gmail.com;


Darin Kopp (Co-Presenter/Co-Author), University of Oklahoma, darinkopp@gmail.com;


Daniel Allen (Co-Presenter/Co-Author), University of Oklahoma, dcallen@ou.edu;


Michelle Busch (Primary Presenter/Author), University of Oklahoma, buschmh@ou.edu;


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14:15 - 14:30: / 151 G INTERMITTENT STREAM DYNAMICS AT THE CATCHMENT SCALE: CAPTURING STREAMBED INTERACTIONS FROM FIRST ORDER TRIBUTARIES TO THE MAINSTEM

5/21/2019  |   14:15 - 14:30   |  151 G

INTERMITTENT STREAM DYNAMICS AT THE CATCHMENT SCALE: CAPTURING STREAMBED INTERACTIONS FROM FIRST ORDER TRIBUTARIES TO THE MAINSTEM Infiltration along intermittent and ephemeral stream channels affects streamflow permanence, wetting-drying dynamics, and flow magnitudes, thus determining the biological processes critical for biotic communities’ seasonal colonization and catchment health. The permeability of streambed sediments controls infiltration; therefore, we need to understand variability in streambed sediments throughout stream basins. However, catchment-scale studies of streambed characteristics are rare; most often, we use point, transect, or short-reach measurements, which do not lend themselves to upscaling. Using continuous measurements of shallow geophysics, we surveyed 30 km (9% of total channel length) of dry stream channel in a small catchment in South Australia, including first to fifth order stream reaches across five soil types. The results show changes in apparent conductivity down to 4 m below ground. The data reveals the longitudinal and vertical patchiness of streambed sediments, identifies a clogging layer at the streambed surface, and suggests areas of sandy vs clayey sediments. This work provides a rare glimpse into catchment-scale streambed dynamics, as well as important lessons on researcher- landowner dynamics in a small catchment.

Margaret Shanafield (Primary Presenter/Author), Flinders University, margaret.shanafield@flinders.edu.au;


Karina Gutierrez-Jurado (Co-Presenter/Co-Author), Flinders University, karina.gutierrez@flinders.edu.au;


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14:30 - 14:45: / 151 G LONG-TERM COMMUNITY RESPONSES TO AND RECOVERY FROM DRYING VARY ACROSS TEMPERATE-CLIMATE STREAMS WITH DIFFERENT FLOW PERMANENCE REGIMES

5/21/2019  |   14:30 - 14:45   |  151 G

LONG-TERM COMMUNITY RESPONSES TO AND RECOVERY FROM DRYING VARY ACROSS TEMPERATE-CLIMATE STREAMS WITH DIFFERENT FLOW PERMANENCE REGIMES Most river networks include reaches with perennial flow, near-perennial reaches that dry during drought disturbances, and intermittent reaches that dry seasonally. The frequency, duration and regional extent of drying drive aquatic community composition, though studies combining multiple aspects of drying across streams with different flow regimes remain rare, especially in cool, wet temperate regions. We explored aquatic invertebrate in relation to discharge data at 46 sites over a 25-year period encompassing ‘normal’ and drought years, to assess how hydrological metrics characterizing different aspects of drying affect alpha and beta diversities at sites with different permanence regimes. Alpha diversity decreased with drying duration in the preceding summer and increased with the time since drying, decreasing more steeply and taking longer to recover at near-perennial than intermittent sites. Beta diversity increased with the spatial extent of drying, reflecting increases in environmental heterogeneity among sites. Contrasting community responses to drying at sites with different flow permanence regimes promoted persistence of the regional species pool and thus post-drying recolonization. However, predicted increases in drought duration and frequency may threaten biodiversity if disturbance intensity exceeds community resistance and recovery capacities.

Romain Sarremejane (Primary Presenter/Author), Nottingham Trent University, romain.sarremejane@gmail.com;


Rachel Stubbington (Co-Presenter/Co-Author), Nottingham Trent University, rachel.stubbington@ntu.ac.uk;


Judy England (Co-Presenter/Co-Author), Environment Agency, judy.england@environment-agency.gov.uk;


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14:45 - 15:00: / 151 G PREDICTING THE SPATIAL AND TEMPORAL DISTRIBUTION OF WETTED HABITATS IN INTERMITTENT STREAMS AND ITS IMPLICATIONS FOR LONG-TERM DROUGHT IMPACTS

5/21/2019  |   14:45 - 15:00   |  151 G

PREDICTING THE SPATIAL AND TEMPORAL DISTRIBUTION OF WETTED HABITATS IN INTERMITTENT STREAMS AND ITS IMPLICATIONS FOR LONG-TERM DROUGHT IMPACTS Intermittent streams are common in California, and insufficient summer streamflow is often cited as a bottleneck for species survival in this region. During dry periods, aquatic organisms depend on persistent wetted reaches and isolated pools for refuge, from which they may recolonize surrounding habitats upon rewetting. Despite the importance of intermittent streams for maintaining regional biodiversity, little is known about the physical controls on the drying dynamics, nor the processes that sustain viable refugia throughout the dry season. This study aims to identify the spatio-temporal controls on wetted habitat availability in intermittent streams within two California watersheds (Coyote Creek in Santa Clara County and the Russian River in Sonoma County). These two watersheds occur in different hydrologic regions and support different fish communities, allowing us to explore the generality of results in different contexts. Using wet-dry mapping data collected among and within years in combination with antecedent climatic data and landscape-level variables, we aim to understand the predictability of the degree and distribution of stream drying. Our approach provides insight on the patterns of stream drying, and is useful for guiding management decisions and conservation action during extreme drought conditions.

Hana Moidu (Primary Presenter/Author), University of California, Berkeley, hanamoidu@berkeley.edu;


Ross Vander Vorste (Co-Presenter/Co-Author), University of California Berkeley, vandervorste.ross@gmail.com;


Pablo Rodríguez-Lozano (Co-Presenter/Co-Author), Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, U.S., pablorodriguezlozano@berkeley.edu;


Mariska Obedzinski (Co-Presenter/Co-Author), California Sea Grant, mobedzinski@ucsd.edu;


Ted Grantham (Co-Presenter/Co-Author), University of California, Berkeley, tgrantham@berkeley.edu;


Stephanie Carlson (Co-Presenter/Co-Author), Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, U.S., smcarlson@berkeley.edu;


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15:15 - 15:30: / 151 G VALIDATING RAPID ASSESSMENT FOR EPISODIC STREAMS

5/21/2019  |   15:15 - 15:30   |  151 G

VALIDATING RAPID ASSESSMENT FOR EPISODIC STREAMS Many of the Arid West’s streams are characterized by episodic, ephemeral flow conditions, but they have been underrepresented in research and management. Assessment tools for these streams are necessary to prioritize streams for protection or restoration, assess impacts, and evaluate mitigation efforts. Previous work developed an initial module of the California Rapid Assessment (CRAM) for episodic streams, and this project refined and clarified the assessment method before employing it. CRAM is organized to guide the user through the stream’s structure from landscape level to site-specific plant community composition. Project partners concurrently collected samples of terrestrial invertebrates and bryophytes, with the goal of developing an index of condition, and these data will be used to validate the rapid assessment. The site selection process targeted Arizona and California’s arid regions, including the Mojave and Sonoran Deserts, The Mogollon Rim, Death Valley, Owens Valley, Mono Lake, the Central Coast, and the Modoc Plateau, and a pending phase will include the southern San Joaquin Valley. Initial results indicate that the rapid assessment is functioning as intended to measure a full range of environmental conditions.

Cara Clark (Primary Presenter/Author), Moss Landing Marine Laboratories, cclark@mlml.calstate.edu;


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