SFS Annual Meeting

5/21/2019  |   09:00 - 09:15   |  254 B

STREAM COMMUNITY ASSEMBLY 36 YEARS AFTER THE CATASTROPHIC ERUPTION OF MOUNT ST. HELENS The eruption of Mount St. Helens (WA, USA) in 1980 obliterated forests and buried streams on the mountain’s north flank by over 100m of sterile pumice. Following the eruption, springs and snowmelt created four new watersheds flowing into Spirit Lake. Community recovery was predicted to take many decades to centuries, but surveys 36 years post-eruption found significant aquatic community development. Reach-scale surveys in the four watersheds reveal large ranges in many physio-chemical characteristics including water temperature, discharge, conductivity, organic carbon, nitrate, and canopy cover. Communities of periphyton, macroinvertebrates, and riparian plants differ significantly among streams suggesting different developmental trajectories for primary succession. In one stream, only low-profile and firmly attached soft-algae taxa were observed, along with fewer riparian plants and benthic invertebrates. We suspect that continual disturbances by floods and sediment transport are keeping the aquatic and riparian communities in earlier successional states of development. The other streams are warmer with lower discharge and sediment transport, and tend support more diverse and/or abundant taxa and canopy cover. The large differences in habitat across the four watersheds provide a unique opportunity to explore in-stream community development and early stream succession.

Shannon Claeson (Primary Presenter/Author), USFS PNW Research Station, shannon.claeson@usda.gov;


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


Rosalina Stancheva (Co-Presenter/Co-Author), George Mason University, rchris13@gmu.edu;


Emily Wolfe (Co-Presenter/Co-Author), Portland State University, Emwolfe@pdx.edu;


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5/21/2019  |   09:15 - 09:30   |  254 B

RESPONSES OF STREAM INVERTEBRATE AND FISH ASSEMBLAGES TO AN EXTREME FLOOD EVENT IN A JAPANESE RIVER Ongoing climate change is causing the frequent occurrence of massive floods worldwide. However, there is limited information on the impact of such extreme flood disturbances on lotic organisms owing to its rarity of occurrence and thus the difficulty in observation. In September 2017, an unprecedented flood occurred in the Shigenobu River on Sikoku Island, southwestern Japan. We report the changes in invertebrate and fish assemblages caused by the extreme flood based on a rare dataset obtained just before and after the peak flow. We also compared the response of the assemblages among four representative channel unit types in a targeted river segment. We observed significant decrease in invertebrate density and taxon richness after the flood. In contrast, fish abundance decreased in riffles and rather increased in backwater habitat. Analyses of the individual species showed the aggregation of pale chub at backwaters after the flood, implying that such semi-lentic habitats serve as a flow refugia for water-column fishes during high flow. Consequently, we showed strong impacts of an extreme flood event on invertebrate and fish assemblages, and that the effects differed between these taxa and between channel unit types.

Kosuke Sumida (Co-Presenter/Co-Author), Ehime University, sumida.kohsuke.14@cee.ehime-u.ac.jp;


Yo Miyake (Primary Presenter/Author), Ehime University, yomiyakejapan@gmail.com;


Yuya Watanabe (Co-Presenter/Co-Author), Fujita Construction Consultant, yuya-watanabe@fujitacc.co.jp;


Mikio Inoue (Co-Presenter/Co-Author), Ehime University, inom@sci.ehime-u.ac.jp;


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5/21/2019  |   09:30 - 09:45   |  254 B

MURPHY'S LAW AND THE ANALOG JORDAN RIVER, UT: INVASIVES RULE Welcome to the Jordan River. Arguably Utah's most polluted river. What could go wrong did go wrong. The river and its tributaries have been dewatered and channelized starting on the second day of Mormon settlement with no end in sight. Prior; beaver were the dominant ecosystem engineers and at least a dozen native fish species along with one of the most diverse molluscan assemblages in the western USA called the river home. Now invasives completely dominate ecosystem functioning including: Asian clams, New Zealand mud snails, and European carp, to name a few. We will discuss our findings on the ecology of this second rate analog and how at least two invasive species now regulate ecosystem function and water quality, without which the Jordan River would likely function as no more than a conveyance canal.

David Richards (Primary Presenter/Author), OreoHelix Consulting, mudsnail1@hotmail.com;


Theron Miller (Co-Presenter/Co-Author), Wasatch Front Water Quality Council, theron.miller12@gmail.com;


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5/21/2019  |   09:45 - 10:00   |  254 B

HURRICANE DISTURBANCE AND BENTHIC MACROINVERTEBRATE ASSEMBLAGES IN EL YUNQUE NATIONAL FOREST, PUERTO RICO Hurricanes are recurrent disturbances in the Caribbean. However, climate change models predict an increase in storm frequency for the region. Hurricane winds remove the forest canopy and create high discharge events during the storm. Our main objective is to assess the impacts of hurricanes Irma and Maria, which hit Puerto Rico in September 2017, on the composition and structure of benthic macroinvertebrate assemblages in streams draining El Yunque National Forest in Puerto Rico. We sampled riffle and pool habitats in two headwater streams draining tabonuco forest before and after the hurricanes impacted the island. Over 40 macroinvertebrate taxa were found, dominated by Leptophlebiidae (Ephemeroptera), Chironomidae (Diptera), Elmidae (Coleoptera), Hydropsychidae and Calamoceratidae (Trichoptera), and Oligochaeta. Hurricanes resulted in large floods and created debris dams. The storms significantly decreased macroinvertebrate abundance. The magnitude of the impacts were severe, but of similar magnitude of those observed for less intense storms. Frequent floods are common in our study region, thus assemblages are adapted and can recover quickly. We hypothesize that major hurricane impacts are associated with canopy opening and changes to the energy resources for stream food webs and not with flood disturbance.

Alonso Ramírez (Primary Presenter/Author), North Carolina State University, alonso.ramirez@ncsu.edu;


Pablo E. Gutiérrez-Fonseca (Co-Presenter/Co-Author), University of Costa Rica, pabloe.gutierrezfonseca@gmail.com;


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5/21/2019  |   10:00 - 10:15   |  254 B

PERSISTENT LATERAL NITROGEN LOSS TEN YEARS AFTER TUNDRA WILDFIRE Climate change is triggering widespread ecosystem disturbance across the permafrost zone, including rapidly increased incidence of tundra wildfire.Wildfire extent and intensity have, with unknown consequences for Arctic terrestrial and aquatic ecosystem biogeochemistry, as wildfire may cause terrestrial vegetation shifts, increasing productivity and nutrient demand; alternatively, wildfire regimes may intensify lateral nutrient loss from the landscapes into adjacent river networks. To address this unknown, we used the river network as a sensor, collecting water samples from 60 burned and unburned watersheds around the Anaktuvuk River fire scar in northern Alaska. We used a novel aerial sampling technique to collect samples three times during the flow seasons of 2017 and 2018, ten years after the wildfire. Despite a decade of ecosystem recovery, we observed nearly a doubling of total dissolved nitrogen concentration, primarily due to elevated organic nitrogen and secondarily from inorganic nitrogen increases. Isotopic analysis suggests that burn-mobilized lateral nitrogen flux comes from old soil nitrogen, not newly-fixed inputs from vegetation shifts. These findings indicate that tundra wildfire could destabilize nitrogen previously stored in permafrost, potentially exacerbating terrestrial nitrogen limitation and altering aquatic and estuarine ecosystems in the permafrost zone.

Benjamin Abbott (Co-Presenter/Co-Author), Brigham Young University, Department of Plant and Wildlife Sciences, benabbott@byu.edu;


William Breck Bowden (Co-Presenter/Co-Author), University of Vermont, breck.bowden@uvm.edu;


Greg Carling (Co-Presenter/Co-Author), Brigham Young University, greg.carling@byu.edu;


Rebecca Frei (Co-Presenter/Co-Author), Brigham Young University, Department of Plant and Wildlife Sciences, beccafrei@gmail.com;


Frances Iannucci (Co-Presenter/Co-Author), University of Alaska Fairbanks, fiannucci@alaska.edu;


Ludda Ludwig (Co-Presenter/Co-Author), University of Alaska Fairbanks, ludda.ludwig@gmail.com;


Adrian Rocha` (Co-Presenter/Co-Author), University of Notre Dame, arocha1@nd.edu;


Arial Shogren (Co-Presenter/Co-Author), University of Alabama, ashogren@ua.edu;
Assistant Professor, Department of Biological Sciences, University of Alabama

Rachel Watts (Co-Presenter/Co-Author), Brigham Young University, Department of Plant and Wildlife Sciences, miss.rachelwatts64@gmail.com;


Jay Zarnetske (Co-Presenter/Co-Author), Department of Earth and Environmental Sciences, Michigan State University, jpz@msu.edu;


Samuel Bratsman (Primary Presenter/Author), Brigham Young University, Department of Plant and Wildlife Sciences, sbratsmanx@gmail.com;


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