SFS Annual Meeting

5/22/2018  |   11:00 - 11:15   |  410 B

HABITAT AND ECOLOGICAL RESPONSE OF STREAMS TO RECURRENT ATYPICAL SUMMER FLOODING IN GLACIER BAY, ALASKA. Flood regimes are a significant controlling variable in fluvial habitat and ecosystem structuring. Shifts in precipitation timing and intensity have driven increases in flood magnitude and frequency. However, the significance of such changes for habitat complexity and biotic communities is unclear, whilst the importance of flood timing in biotic recovery is unknown. Our understanding is further limited by the absence of long term analyses of system response (resistance and resilience). Here, we show the significant role recurrent, atypical, summer flooding played in altering habitat heterogeneity and biotic community composition, across a habitat complexity gradient. Additionally, we compare response to these recent floods (2014) and major winter floods (2005) within the context of a unique long term dataset (>30 years). Habitat and ecological response to the summer floods varied across the habitat complexity gradient. Less complex systems demonstrated high resistance of biotic communities although habitat complexity resilience was low. Contrastingly, complex systems resistance was low in spite of high resilience of habitat complexity. Macroinvertebrate communities were more similar across the habitat complexity gradient following flooding. Our findings provide an important foundation for understanding habitat and ecological implications of changing flood regimes.

Megan Klaar (Co-Presenter/Co-Author), University of Leeds, UK, M.J.Klaar@leeds.ac.uk;


Victoria Milner (Co-Presenter/Co-Author), University of Worcester, v.milner@worc.ac.uk;


Lee Brown (Co-Presenter/Co-Author), University of Leeds, UK, l.brown@leeds.ac.uk;


Jonathan Carrivick (Co-Presenter/Co-Author), University of Leeds, UK, j.l.carrivick@leeds.ac.uk;


Lawrence Eagle (Primary Presenter/Author), University of Leeds, UK, gyle@leeds.ac.uk;


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5/22/2018  |   11:15 - 11:30   |  410 B

USE OF STRUCTURE-FROM-MOTION PHOTOGRAMMETRY TO EVALUATE FLUVIAL SUBSTRATES The size structure of native streambed substrates is a key component of stream ecosystems and habitat for communities. To assess habitat and monitor restoration, direct measurements (e.g. pebble counts) are commonly used to characterize streambed substrates, which can be time consuming, biased, and only assess a subsample of substrates available to biota. Alternative methods have been proposed, such as measuring streambed surface roughness using terrestrial laser scanning (TLS). Structure-from-Motion (SfM) is a photogrammetric technique previously used for modeling topographic features, while being more economical than TLS. We are evaluating SfM for conducting more accurate and efficient assessments of instream substrates and habitat by modelling submerged streambed roughness. Lab trials comparing SfM roughness estimates to pebble counts for coarse substrates reveal a strong relationship between the two methods (r2>0.95), and repeated SfM models have a high degree of similarity (mean difference = 1mm). However, in trials with >75% fine sediment this relationship was less strong (r2<0.60) as a result of SfM characterizing detail not captured by pebble count. SfM appears to be an efficient and appropriate alternative to direct substrate measurements across the range of streambed substrates typically observed.

Brian Danhoff (Primary Presenter/Author), Michigan Technological University, bmdanhof@mtu.edu;


Casey Huckins (Co-Presenter/Co-Author), Michigan Technological University, cjhuckin@mtu.edu;


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5/22/2018  |   11:30 - 11:45   |  410 B

MACROINVERTEBRATE COMMUNITY RESPONSE TO FLOW IN TWO HEADWATER STREAMS OF COSTA RICA Rising global temperature is a driver altering intensity and duration of precipitation in tropical wet and dry seasons. Extremes in hydrological events combined with increasing population and tourism in Costa Rica are projected to affect local water availability. We are quantified the effects of seasonal flow variation on aquatic macroinvertebrate communities within two headwater streams, one intermittent and the other perennial, in the Pacific North of Costa Rica. We sampled macroinvertebrates monthly over a year in riffle, pool and leaf litter habitats. A total of 79 invertebrate taxa were found. Non-metric multidimensional scaling (NMDS) analyses indicated dissimilarities in macroinvertebrate abundance and composition between the two streams (ADONIS p<0.05). A similarity percentages (SIMPER) test of macroinvertebrate abundance indicated that the highest contributors to these differences were Non-Tanypodinae Chironomidae, Calosopsyche, Anchytarsus, Simulium, Leptonema, Tanypodinae Chironomidae and Leptohyphes. These results may provide a better understanding into life history traits that allow persistence of taxa through disturbances. Understanding the ecological response of these relatively under-studied systems will help us better prepare for the consequences of projected changes in stream flows.

Darixa Hernandez Abrams (Primary Presenter/Author), US Army Corps of Engineers, darixa.hernandez@uga.edu;


Scott Connelly (Co-Presenter/Co-Author), University of Georgia, scottcon@uga.edu;


Seth Wenger (Co-Presenter/Co-Author), Odum School of Ecology, University of Georgia, swenger@uga.edu;


Mary Freeman (Co-Presenter/Co-Author), US Geological Survey, mcfreeman@usgs.gov;


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5/22/2018  |   11:45 - 12:00   |  410 B

USING NEON OBSERVATORY DATA TO ASSESS THE EFFECTS OF HURRICANE DISTURBANCE ON PUERTO RICO HEADWATER STREAM COMMUNITIES The National Ecological Observatory Network (NEON) is a research platform designed to assess the impacts of ecological change on ecosystems in continental North America,Puerto Rico,and Alaska. NEON’s aquatic program is comprised of a suite of instrument and observational data collected at 34 sites, including two headwater streams in southwest Puerto Rico. Rio Cupeyes is a high-gradient, forested catchment and Rio Guilarte is in an agricultural catchment. Sampling began at both sites using standard NEON protocols in 2015, with fish sampling starting in February 2017. In September 2017, Hurricanes Irma and Maria made landfall in Puerto Rico, causing visible morphologic change to both NEON aquatic sites. Baseline species richness in Rio Cupeyes and Rio Guilarte is 4 fish species each and 114 and 117 macroinvertebrate taxa, respectively. Standardized sampling was conducted post- hurricane, suggesting a significant decrease in fish abundance. We anticipate a similar trend in the post-hurricane macroinvertebrate community. Using NEON abiotic data such as stream discharge, water chemistry, and stream morphology, we are able to analyze trends in macroinvertebrate and fish community metrics data pre- and post-disturbance.

Stephanie Parker (Primary Presenter/Author), Battelle, National Ecological Observatory Network (NEON), sparker@battelleecology.org;
NEON Aquatic Ecologist and Research Scientist

Brandon Jensen (Co-Presenter/Co-Author), National Ecological Observatory Network - Battelle Ecology, bjensen@battelleecology.org;


Maria Viggiano (Co-Presenter/Co-Author), National Ecological Observatory Network - Battelle Ecology, mviggiano@battelleecology.org;


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5/22/2018  |   12:00 - 12:15   |  410 B

PREDICTING SPECIES PERSISTENCE ACROSS TEMPORAL AND SPATIAL SCALES OF DISTURBANCE: INTERANNUAL VARIABILITY IN TROPICAL MONTANE STREAM INSECT COMMUNITIES Community responses to disturbance are determined both by spatial and temporal scales of disturbing forces and by species-level traits that control resistance and resilience to disturbance. We hypothesized that landscape-scale landslide and flood disturbance history would determine spatial community composition, while site-level physical characteristics, specifically hydrologic flashiness and streambed stability, and species-level traits, specifically drift propensity and colonization ability, would predict persistence through time. We collected stream insect community composition data in ten small headwater streams across a flood and landslide disturbance history and elevation gradient in the Napo drainage in Ecuador. Our community dataset spans five years, including years before and after major landslides and flooding occurred at our sites, a uniquely extensive Neotropical stream insect dataset across temporal and spatial scales. We also carried out drift surveys and patch-scale colonization experiments during two years at a representative subset of those sites to characterize stream insect mobility traits for Neotropical stream insects. Community composition varied more on interannual scales at sites with more frequent disturbance events and lower streambed stability, with mobility traits driving species-level responses, and, surprisingly, functional and taxonomic diversity were higher at these disturbance-prone sites.

Erin Larson (Primary Presenter/Author), University of Alaska-Anchorage, ern.larson@gmail.com;


Andrea C. Encalada (Co-Presenter/Co-Author), Instituto BIOSFERA, Universidad San Francisco de Quito, Cumbayá, Ecuador Biológicas y Ambientales, Universidad San Francisco de Quito, Cumbaya, Ecuador, aencalada@usfq.edu.ec;


LeRoy Poff (Co-Presenter/Co-Author), Colorado State University, n.poff@rams.colostate.edu;


Carla L. Atkinson (Co-Presenter/Co-Author), University of Alabama, carlalatkinson@gmail.com;


Alexander Flecker (Co-Presenter/Co-Author), Cornell University, Ithaca, NY, USA, asf3@cornell.edu;


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