SFS Annual Meeting

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

BASIN FEATURES INFLUENCE THE QUANTITY OF AQUATIC INSECT SUBSIDIES REACHING TERRESTRIAL LANDSCAPES Aquatic and terrestrial ecosystems are coupled by material and energy fluxes. Although the quantity of aquatic-derived resources reaching the terrestrial environment can control the magnitude of consumer response, attaining spatially explicit estimates of allochthonous inputs are challenging. Among the diversity of linkages between the systems, aquatic insects play a major role in the aquatic-to-terrestrial pathway. The quantity of insects emerging from a stream is a proportion of benthic secondary production which decays with distance from the channel. Here, we first use annual community secondary production (ACSP) values from a recently available global database and emergence-production ratios obtained from the literature to estimate the quantity of insect biomass exported form lotic ecosystems throughout the US. Then, we use relative abundances of aquatic insects with terrestrial adult life-stages (i.e. stoneflies, caddisflies, mayflies, dragonflies and midges) from benthic macroinvertebrate monitoring data to parameterize the subsidy distance-decay relationship. Finally, we apply a machine learning routine to investigate statistical relationships between quantity of emergent insects, rate of decay and basin features. By combining, large-scale datasets, machine learning techniques, and meta-analysis we highlight potential broad-scale controls on aquatic-terrestrial linkages.

Darin Kopp (Primary Presenter/Author), U.S. Environmental Protection Agency, Kopp.Darin@epa.gov;
Darin Kopp earned a BS in biology and environmental science from DePaul University, a MS in wildlife science from New Mexico State University and a PhD in ecology and evolutionary biology from the University of Oklahoma. He has expertise in ecological modeling and data synthesis and his research typically focuses on understanding biological patterns at regional, continental and global scales. For his dissertation he focused on quantifying the potential redistribution of materials and energy from streams and rivers to adjacent terrestrial ecosystems using existing geospatial and biomonitoring datasets for the contiguous United States. After completing his PhD, he received an ORISE Postdoctoral Research Fellowship with the US Environmental Protection Agency’s Pacific Ecological Systems Division to investigate methods to improve biological assessments of streams and rivers at the national scale. In collaboration with several principal investigators from the National Aquatic Resource Surveys, his is using multi-species distribution models for aquatic benthic macroinvertebrates and fish to quantify geographic variation in taxon-specific relationships with environmental gradients that are commonly altered by anthropogenic activities.

Daniel Allen (Co-Presenter/Co-Author), The Pennsylvania State University, dca5269@psu.edu;


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

THE IMPACT OF GENOTYPIC VS. ENVIRONMENTAL VARIATION IN LEAF LITTER ON AQUATIC COMMUNITY ASSEMBLAGE AND DECOMPOSITION The genotype of a foundation species can affect the survival and abundance of other species. For example, studies have shown intraspecific genetic variation in cottonwoods produces community- and ecosystem-level effects; however, it is unknown exactly how these extended phenotypes will respond to changed environmental conditions. Because Cottonwood litter forms an important energy link between terrestrial and aquatic systems, we sought to quantify the extent to which variation in leaf litter traits, aquatic litter decomposition rates, and aquatic invertebrate community assemblage is due to genetic vs. environmental effects. We collected litter from Populus fremontii growing in common gardens planted across an elevational gradient and placed it in a mid-range stream to measure decomposition rates and colonization by aquatic invertebrates. We found that leaf litter traits and decomposition were strongly affected by an interaction between population and garden, while aquatic invertebrate communities were strongly influenced by garden effect. Our results indicate that genotype by environment interactions can have a major influence on the extended phenotypic effects of a foundation tree species, shifting our ability to predict the ecological roles particular genotypes or source populations will play when planted into new environments.

Jane Marks (Co-Presenter/Co-Author), Northern Arizona University, jane.marks@nau.edu;


Thomas Whitham (Co-Presenter/Co-Author), Northern Arizona University, Thomas.Whitham@nau.edu;


Gerard Allan (Co-Presenter/Co-Author), Northern Arizona University, gery.allan@nau.edu;


Rebecca Best (Co-Presenter/Co-Author), Northern Arizona University, rebecca.best@nau.edu;


Joann Jeplawy (Primary Presenter/Author), Northern Arizona University, jrj295@nau.edu;


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

HYDROPOWER AND AQUATIC-TERRESTRIAL LINKAGES IN THE COLORADO RIVER Like many of the world’s large rivers, the Colorado River is interrupted by several dams over its course. The operation of one of these dams, Glen Canyon Dam, to generate hydroelectricity has created an artificial tide in its downstream stretch of the Colorado River, which has produced a pattern of variable aquatic insect emergence. Emergent insects, however, are not isolated to the aquatic ecosystem. Studies in other riparian systems show these insects are an integral part of terrestrial riparian food webs. Therefore, we sought to determine if hydropeaking, through its effects on emergence, also affects riparian consumer diets. To do this, tissue samples were collected from riparian consumers, specifically lizards and rodents, downstream of Glen Canyon Dam across a gradient of insect emergence. Carbon, nitrogen, oxygen, and hydrogen isotopes measured in each sample showed variation in the source (aquatic vs. terrestrial) of riparian consumer diets, potentially indicating a response to emergent insect abundance. These results are relevant to the management of dams, both within this system and globally, as their operations can affect not just the aquatic food web, but also surrounding, linked food webs.

Christina Lupoli (Primary Presenter/Author), Arizona State University, caclupoli@gmail.com;


Ted Kennedy (Co-Presenter/Co-Author), USGS Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, tkennedy@usgs.gov;


Jeffrey Muehlbauer (Co-Presenter/Co-Author), University of Alaska Fairbanks, USGS Alaska Cooperative Fish and Wildlife Research Unit, jdmuehlbauer@alaska.edu;


John Sabo (Co-Presenter/Co-Author), Arizona State University, John.L.Sabo@asu.edu;


Charles Yackulic (Co-Presenter/Co-Author), USGS Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, cyackulic@usgs.gov;


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

EFFECTS OF HYDROLOGICAL ALTERATIONS TO A MIDWESTERN STREAM ON INSECT EMERGENCE PRODUCTION AND RIPARIAN SPIDER DIETS Patterns of adult aquatic insect emergence vary seasonally and are influenced by physical factors such as hydrology and substrata. The Cache River, located in southern Illinois, has undergone several hydrologic alterations over the past century. The construction of the Post Creek cutoff effectively divided the system into the upper Cache River (UCR) and lower Cache River (LCR). This resulted in increased water velocities and erosion in the UCR and decreased flow and dissolved oxygen in the LCR. To examine how hydrology influenced stream communities, we measured emerging insect abundance, richness, and diversity in the UCR and LCR during 2017-2018. There was no significant difference in the diversity of emerging insects between the UCR and LCR (p = 0.68). However, richness (p = 0.02) and abundance (p = 0.01) were both significantly higher in the UCR. We hypothesize that differences in emergence production between the two reaches are affecting nutrient subsidy exports to adjacent terrestrial food webs and are currently comparing long-chain polyunsaturated acid (LC-PUFA) levels in riparian spiders from the UCR and LCR. Our research demonstrates that hydrological alterations to streams can have cascading effects on terrestrial systems.

Katie Heiden (Primary Presenter/Author), Southern Illinois University, Katie.heiden@siu.edu;


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5/21/2019  |   15:00 - 15:15   |  151 ABC

UPSCALING BIODIVERSITY EXPERIMENTS TO FUNCTIONING OF RIVERINE CATCHMENTS A central problem for understanding the relationship between biodiversity and ecosystem functioning is how to scale up the results of plot-scale or laboratory experiments to real ecosystems. Here, we investigated the roles of diversity and density of dominant shredding macroinvertebrates on leaf litter decomposition in forested headwater streams, where terrestrial inputs are an essential resource for the food web. In laboratory experiments, we found that increasing shredder richness has as additive effect on leaf litter processing. Thus differences between species are important in determining ecosystem function, and there was little evidence of non-additive interactions that would complicate upscaling. Next, field surveys revealed that coexistence of different shredder species was rare within catchments, despite overlapping regional distributions. This reinforces that species identity rather than richness is important for predicting ecosystem functioning. Returning to the laboratory, we found that per-capita contribution to decomposition declines with increasing density, likely due to interference competition. We conclude by using this laboratory and field data to make upscaled predictions of decomposition in real stream catchments, showing that incorporating spatial heterogeneity in density and density-dependent behavior can drastically alter predictions of ecosystem function.

Chelsea J. Little (Primary Presenter/Author), Simon Fraser University, chelsea_little@sfu.ca;


Florian Altermatt (Co-Presenter/Co-Author), Eawag, Swiss Federal Institute of Aquatic Science and Technology, florian.altermatt@eawag.ch;


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

IMPACTS OF SHORELINE RESTORATION AND SOURCE OF NUTRIENT ENRICHMENT ON MACROPHYTE AND EPIPHYTIC ALGAL COMMUNITIES Macrophytes are critical to littoral zones by providing sediment stability, habitat refugia, and nutrient cycling. Epiphytic algae reside on macrophyte surfaces and their proximity can alter resource availability (i.e., nutrients, light). As bioindicators, both macrophytes and algae are increasingly used to detect aquatic anthropogenic alterations. With an industrial past, Muskegon Lake (MI) has undergone human disturbances, such as shoreline hardening and sediment contamination. Lake restoration included shoreline softening; we conducted a macrophyte survey (2009-2012, 2018) to assess immediate and long-term ecological improvements. Survey results suggest that macrophyte biomass and densities have recovered from initial restoration, and post-restoration communities may be more resilient to annual hydrologic variations. One factor potentially influencing macrophyte and epiphytic algae dynamics is the source of nutrient loading (i.e., water column or sediment), as each primary producer has differential access to nutrients. To address the role of nutrient source, a mesocosm experiment was conducted using the macrophyte Vallisneria americana. Nitrogen and phosphorus were added to the water column and/or sediment of 12 mesocosms in a factorial design to evaluate macrophyte biomass and algal community structure changes. Preliminary results indicate water column nutrients stimulate higher epiphytic algae growth.

Alan Steinman (Co-Presenter/Co-Author), Annis Water Resources Institute-Grand Valley State University, steinmaa@gvsu.edu;


Paige Kleindl (Primary Presenter/Author), Annis Water Resources Institute-Grand Valley State University, kleindlp@mail.gvsu.edu;


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