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Portland State University

Environmental Science and Management Faculty Publications and Presentations

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2019

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Effects Of Environmentally Relevant Concentrations Of Microplastic Fibers On Pacific Mole Crab (Emerita Analoga) Mortality And Reproduction, Dorothy Horn, Elise F. Granek, Clare Steele Dec 2019

Effects Of Environmentally Relevant Concentrations Of Microplastic Fibers On Pacific Mole Crab (Emerita Analoga) Mortality And Reproduction, Dorothy Horn, Elise F. Granek, Clare Steele

Environmental Science and Management Faculty Publications and Presentations

Microplastics are ubiquitous in marine systems; however, knowledge of the effects of these particles on marine fauna is limited. Ocean-borne plastic debris accumulates in littoral ecosystems worldwide, and invertebrate infauna inhabiting these systems can ingest small plastic particles and fibers, mistaking them for food. We examined the effect of microplastic fibers on physiological and reproductive outcomes in a nearshore organism by exposing Pacific mole crabs (Emerita analoga) to environmentally relevant concentrations of microsized polypropylene rope fibers. We compared adult gravid female crab mortality, reproductive success, and embryonic developmental rates between microfiber-exposed and control crabs. Pacific mole crabs exposed to polypropylene …


Microplastic Concentrations In Two Oregon Bivalve Species: Spatial, Temporal, And Species Variability, Britta Baechler, Elise F. Granek, Matthew V. Hunter, Kathleen E. Conn Nov 2019

Microplastic Concentrations In Two Oregon Bivalve Species: Spatial, Temporal, And Species Variability, Britta Baechler, Elise F. Granek, Matthew V. Hunter, Kathleen E. Conn

Environmental Science and Management Faculty Publications and Presentations

Microplastics are an ecological stressor with implications for ecosystem and human health when present in seafood. We quantified microplastic types, concentrations, anatomical burdens, geographic distribution, and temporal differences in Pacific oysters (Crassostrea gigas) and Pacific razor clams (Siliqua patula) from 15 Oregon coast, U.S.A. sites. Microplastics were present in organisms from all sites. On average, whole oysters and razor clams contained 10.95 ± 0.77 and 8.84 ± 0.45 microplastic pieces per individual, or 0.35 ± 0.04 pieces g−1 tissue and 0.16 ± 0.02 pieces g−1 tissue, respectively. Contamination was quantified but not subtracted. Over …


Microplastic Occurrence And Effects In Commercially Harvested North American Finfish And Shellfish: Current Knowledge And Future Directions, Britta Baechler, Cheyenne Stienbarger, Dorothy Horn, Jincy Joseph, Allison Taylor, Elise F. Granek, Susanne Brander Nov 2019

Microplastic Occurrence And Effects In Commercially Harvested North American Finfish And Shellfish: Current Knowledge And Future Directions, Britta Baechler, Cheyenne Stienbarger, Dorothy Horn, Jincy Joseph, Allison Taylor, Elise F. Granek, Susanne Brander

Environmental Science and Management Faculty Publications and Presentations

Commercial fisheries yield essential foods, sustain cultural practices, and provide widespread employment around the globe. Commercially harvested species face a myriad of anthropogenic threats including degraded habitats, changing climate, overharvest, and pollution. Microplastics are pollutants of increasing concern, which are pervasive in the environment and can harbor or adsorb pollutants from surrounding waters. Aquatic organisms, including commercial species, encounter and ingest microplastics, but there is a paucity of data about those caught and cultured in North America. Additional research is needed to determine prevalence, physiological effects, and population-level implications of microplastics in commercial species from Canada, the United States, and …


Widespread Severe Wildfires Under Climate Change Lead To Increased Forest Homogeneity In Dry Mixed-Conifer Forests, Brooke Alyce Cassell, Robert M. Scheller, Melissa S. Lucash, Matthew Hurteau, E. Louise Loudermilk Nov 2019

Widespread Severe Wildfires Under Climate Change Lead To Increased Forest Homogeneity In Dry Mixed-Conifer Forests, Brooke Alyce Cassell, Robert M. Scheller, Melissa S. Lucash, Matthew Hurteau, E. Louise Loudermilk

Environmental Science and Management Faculty Publications and Presentations

Climate warming in the western United States is causing changes to the wildfire regime in mixed-conifer forests. Rising temperatures, longer fire seasons, increased drought, as well as fire suppression and changes in land use, have led to greater and more severe wildfire activity, all contributing to altered forest composition over the past century. To understand future interactions among climate, wildfire, and vegetation in a fire-prone landscape in the southern Blue Mountains of central Oregon, we used a spatially explicit forest landscape model, LANDIS-II, to simulate forest and fire dynamics under current management practices and two projected climate scenarios. The results …


Social Vulnerability To Large Wildfires In The Western Usa, Palaiologos Palaiologou, Alan A. Ager, Max Nielsen-Pincus, Cody Evers, Michelle A. Day Sep 2019

Social Vulnerability To Large Wildfires In The Western Usa, Palaiologos Palaiologou, Alan A. Ager, Max Nielsen-Pincus, Cody Evers, Michelle A. Day

Environmental Science and Management Faculty Publications and Presentations

Federal land managers in the US can be informed with quantitative assessments of the social conditions of the populations affected by wildfires originating on their administered lands in order to incorporate and adapt their management strategy to achieve a more targeted prioritization of community wildfire protection investments. In addition, these assessments are valuable to socially vulnerable communities for quantifying their exposure to wildfires originating on adjacent land tenures. We assessed fire transmission patterns using fire behavior simulations to understand spatial variations across three diverse study areas (North-central Washington; Central California; and Northern New Mexico) to understand how different land tenures …


Toxic Chemical Governance Failure In The United States: Key Lessons And Paths Forward, Ariana M. Chiapella, Zbigniew Grabowski, Mary Ann Rozance, Ashlie D. Denton, Manar A. Alattar, Elise F. Granek Aug 2019

Toxic Chemical Governance Failure In The United States: Key Lessons And Paths Forward, Ariana M. Chiapella, Zbigniew Grabowski, Mary Ann Rozance, Ashlie D. Denton, Manar A. Alattar, Elise F. Granek

Environmental Science and Management Faculty Publications and Presentations

Over 40 years of regulations in the United States have failed to protect human and environmental health. We contend that these failures result from the flawed governance over the continued production, use, and disposal of toxic chemicals. To address this failure, we need to identify the broader social, political, and technological processes producing, knowing, and regulating toxic chemicals, collectively referred to as toxic chemical governance. To do so, we create a conceptual framework covering five key domains of governance: knowledge production, policy design, monitoring and enforcement, evaluation, and adjudication. Within each domain, social actors of varying power negotiate what constitutes …


Nutrients Mediate The Effects Of Temperature On Methylmercury Concentrations In Freshwater Zooplankton, Meredith P. Jordan, A. Robin Stewart, Collin A. Eagles-Smith, Angela L. Strecker Jun 2019

Nutrients Mediate The Effects Of Temperature On Methylmercury Concentrations In Freshwater Zooplankton, Meredith P. Jordan, A. Robin Stewart, Collin A. Eagles-Smith, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

Methylmercury (MeHg) bioaccumulation in freshwater aquatic systems is impacted by anthropogenic stressors, including climate change and nutrient enrichment. The goal of this study was to determine how warmer water temperatures and excess nutrients would alter zooplankton communities and phytoplankton concentrations, and whether those changes would in turn increase or decrease MeHg concentrations in freshwater zooplankton. To test this, we employed a 2 × 2 factorialexperimental design with nutrient and temperature treatments. Mesocosms were filled with ambient water and plankton from Cottage Grove Reservoir, Oregon, U.S.A., a waterbody that has experienced decades of elevated MeHg concentrations and …


A Landscape Model Of Variable Social-Ecological Fire Regimes, Robert M. Scheller, Alec M. Kretchun, Todd J. Hawbaker, Paul D. Henne Jun 2019

A Landscape Model Of Variable Social-Ecological Fire Regimes, Robert M. Scheller, Alec M. Kretchun, Todd J. Hawbaker, Paul D. Henne

Environmental Science and Management Faculty Publications and Presentations

Fire regimes are now recognized as the product of social processes whereby fire on any landscape is the product of human-generated drivers: climate change, historical patterns of vegetation manipulation, invasive species, active fire suppression, ongoing fuel management efforts, prescribed burning, and accidental ignitions. We developed a new fire model (Social-Climate Related Pyrogenic Processes and their Landscape Effects: SCRPPLE) that emphasizes the social dimensions of fire and enables simulation of fuel-treatment effects, fire suppression, and prescribed fires. Fire behavior was parameterized with daily fire weather, ignition, and fire-boundary data. SCRPPLE was initially parameterized and developed for the Lake Tahoe Basin (LTB) …


Climate And Lawn Management Interact To Control C4 Plant Distribution In Residential Lawns Across Seven U.S. Cities, Tara Trammell, Diane E. Pataki, Christopher Still, James Ehleringer, Meghan Avolio, Jennifer L. Morse, Multiple Additional Authors Jun 2019

Climate And Lawn Management Interact To Control C4 Plant Distribution In Residential Lawns Across Seven U.S. Cities, Tara Trammell, Diane E. Pataki, Christopher Still, James Ehleringer, Meghan Avolio, Jennifer L. Morse, Multiple Additional Authors

Environmental Science and Management Faculty Publications and Presentations

In natural grasslands, C4 plant dominance increases with growing season temperatures and reflects distinct differences in plant growth rates and water use efficiencies of C3 vs. C4 photosynthetic pathways. However, in lawns, management decisions influence interactions between planted turfgrass and weed species, leading to some uncertainty about the degree of human vs. climatic controls on lawn species distributions. We measured herbaceous plant carbon isotope ratios (δ13C, index of C3/C4 relative abundance) and C4 cover in residential lawns across seven U.S. cities to determine how climate, lawn plant management, or interactions between climate and plant management influenced C4 lawn cover. We …


A Mixed-Methods Approach To Determine How Conservation Management Programs And Techniques Have Affected Herbicide Use And Distribution In The Environment Over Time, Melanie Malone, Eugene Foster Apr 2019

A Mixed-Methods Approach To Determine How Conservation Management Programs And Techniques Have Affected Herbicide Use And Distribution In The Environment Over Time, Melanie Malone, Eugene Foster

Environmental Science and Management Faculty Publications and Presentations

No-till agriculture has the ability to reduce fuel consumption, increase soil moisture, reduce soil erosion and increase organic matter. However, it remains unclear whether it increases herbicide use overall in the long term for communities that use no-till as their primary source of conservation agriculture. The preponderance of literature suggests that no-till has increased herbicide use, but it is difficult to quantify how much herbicide has increased in a given location and to directly correlate changes in herbicide use to changes in soil and water quality. This paper provides several methods to determine how herbicide use has changed over time …


Performance Of Genetic Distance Metrics In Gravity And General Mixed Effects Models, Nathan B. Alexander, Crysta Gantz, Jane L. Remfert, Melanie A. Murphy Apr 2019

Performance Of Genetic Distance Metrics In Gravity And General Mixed Effects Models, Nathan B. Alexander, Crysta Gantz, Jane L. Remfert, Melanie A. Murphy

Environmental Science and Management Faculty Publications and Presentations

There are many causes for the genetic patterns that arise among populations across a landscape. Effective population size, natal site preference, geographic distance, or barriers to gene flow associated with landscape composition may work in opposition or in concert resulting in varying degrees of population differentiation. Here, we simulate 40 populations under 3 different ecological hypotheses of individual dispersal with random mating for 1500 generations, with scenarios: 1) dispersal and mating is dependent on habitat between populations, 2) dispersal and mating is dependent on individuals finding habitat similar to their natal habitat, and 3) dispersal and mating is dependent on …


Mountain Lakes: Eyes On Global Environmental Change, Katrina A. Moser, Jill S. Baron, Janice Brahney, Isabella A. Olesky, Jasmine E. Saros, Elizabeth J. Hundey, Steven A. Sadro, Jiri Kopácek, Ruben Sommaruga, Martin J. Kainz, Angela L. Strecker, Sudeep Chandra, David M. Walters, Daniel L. Preston, Neal Michelutti, Fabio Lepori, Sarah A. Spaulding, Kyle R. Christianson, John M. Melack, J. P. Smol Apr 2019

Mountain Lakes: Eyes On Global Environmental Change, Katrina A. Moser, Jill S. Baron, Janice Brahney, Isabella A. Olesky, Jasmine E. Saros, Elizabeth J. Hundey, Steven A. Sadro, Jiri Kopácek, Ruben Sommaruga, Martin J. Kainz, Angela L. Strecker, Sudeep Chandra, David M. Walters, Daniel L. Preston, Neal Michelutti, Fabio Lepori, Sarah A. Spaulding, Kyle R. Christianson, John M. Melack, J. P. Smol

Environmental Science and Management Faculty Publications and Presentations

Mountain lakes are often situated in protected natural areas, a feature that leads to their role as sentinels of global environmental change. Despite variations in latitude, mountain lakes share many features, including their location in catchments with steep topographic gradients, cold temperatures, high incident solar and ultraviolet radiation (UVR), and prolonged ice and snow cover. These characteristics, in turn, affect mountain lake ecosystem structure, diversity, and productivity. The lakes themselves are mostly small and shallow, and up until recently, have been characterized as oligotrophic. This paper provides a review and update of the growing body of research that shows that …


Farmer Attitudes Toward Cooperative Approaches To Herbicide Resistance Management: A Common Pool Ecosystem Service Challenge, David E. Ervin, Elise H. Breshears, George B. Frisvold, Terrance M. Hurley, Katherine E. Dentzman, Jeffrey L. Gunsolus, Raymond A. Jussaume, Micheal D. K. Owen, Jason Norsworthy, Mustofa Mahmud Al Mamun, Wesley Everman Mar 2019

Farmer Attitudes Toward Cooperative Approaches To Herbicide Resistance Management: A Common Pool Ecosystem Service Challenge, David E. Ervin, Elise H. Breshears, George B. Frisvold, Terrance M. Hurley, Katherine E. Dentzman, Jeffrey L. Gunsolus, Raymond A. Jussaume, Micheal D. K. Owen, Jason Norsworthy, Mustofa Mahmud Al Mamun, Wesley Everman

Environmental Science and Management Faculty Publications and Presentations

Dramatic growth in herbicide-resistant (HR) weeds in the United States threatens farm profitability and may undercut environmentally beneficial farming practices. When HR weeds move across farm boundaries due to ecological processes or human action, a common pool resource challenge emerges, requiring farmer cooperation to manage such weeds effectively. We investigate the scope for cooperative management using responses to a national survey on HR weed issues to test a recursive model of three preconditions for collective action: (1) concern about HR weeds migrating from nearby lands; (2) communication with neighbors about HR weeds; and (3) belief that cooperation is necessary for …


Roots Mediate The Effects Of Snowpack Decline On Soil Bacteria, Fungi, And Nitrogen Cycling In A Northern Hardwood Forest, Patrick O. Sorensen, Jennifer M. Bhatnagar, Lynn M. Christenson, Jorge Duran, Timothy J. Fahey, Melany C. Fisk, Adrien C. Finzi, Peter M. Groffman, Jennifer L. Morse, Pamela H. Templer Jan 2019

Roots Mediate The Effects Of Snowpack Decline On Soil Bacteria, Fungi, And Nitrogen Cycling In A Northern Hardwood Forest, Patrick O. Sorensen, Jennifer M. Bhatnagar, Lynn M. Christenson, Jorge Duran, Timothy J. Fahey, Melany C. Fisk, Adrien C. Finzi, Peter M. Groffman, Jennifer L. Morse, Pamela H. Templer

Environmental Science and Management Faculty Publications and Presentations

Rising winter air temperature will reduce snow depth and duration over the next century in northern hardwood forests. Reductions in snow depth may affect soil bacteria and fungi directly, but also affect soil microbes indirectly through effects of snowpack loss on plant roots. We incubated root exclusion and root ingrowth cores across a winter climate-elevation gradient in a northern hardwood forest for 29 months to identify direct (i.e., winter snow-mediated) and indirect (i.e., root-mediated) effects of winter snowpack decline on soil bacterial and fungal communities, as well as on potential nitrification and net N mineralization rates. Both winter snowpack decline …


When Pets Become Pests: The Role Of The Exotic Pet Trade In Producing Invasive Vertebrate Animals, Julie I. Lockwood, Dustin J. Welbourne, Christina M. Romagosa, Phillip Cassey, Nicholas E. Mandrak, Angela L. Strecker, Brian Leung, Oliver C. Stringham, Bradley Udell, Diane J. Episcopio-Sturgeon, Michael F. Tlusty, James Sinclair, Michael R. Springborn, Elizabeth F. Plenaar, Andrew L. Rhyne, Reuben Keller Jan 2019

When Pets Become Pests: The Role Of The Exotic Pet Trade In Producing Invasive Vertebrate Animals, Julie I. Lockwood, Dustin J. Welbourne, Christina M. Romagosa, Phillip Cassey, Nicholas E. Mandrak, Angela L. Strecker, Brian Leung, Oliver C. Stringham, Bradley Udell, Diane J. Episcopio-Sturgeon, Michael F. Tlusty, James Sinclair, Michael R. Springborn, Elizabeth F. Plenaar, Andrew L. Rhyne, Reuben Keller

Environmental Science and Management Faculty Publications and Presentations

The annual trade in exotic vertebrates as pets is a multi-billion- dollar global business. Thousands of species, and tens of millions of individual animals, are shipped both internationally and within countries to satisfy this demand. Most research on the exotic pet trade has focused on its contribution to native biodiversity loss and disease spread. Here, we synthesize information across taxa and research disciplines to document the exotic pet trade’s contribution to vertebrate biological invasions. We show recent and substantial worldwide growth in the number of non-native animal populations introduced via this invasion pathway, which demonstrates a strong potential to increase …


Fine-Scale Assessment Of Cross-Boundary Wildfire Events In The Western United States, Palaiologos Palaiologou, Alan A. Ager, Cody Evers, Max Nielsen-Pincus, Michelle A. Day, Haiganoush K. Preisler Jan 2019

Fine-Scale Assessment Of Cross-Boundary Wildfire Events In The Western United States, Palaiologos Palaiologou, Alan A. Ager, Cody Evers, Max Nielsen-Pincus, Michelle A. Day, Haiganoush K. Preisler

Environmental Science and Management Faculty Publications and Presentations

We report a fine-scale assessment of cross-boundary wildfire events for the western US. We used simulation modeling to quantify the extent of fire exchange among major federal, state, and private land tenures and mapped locations where fire ignitions can potentially affect populated places. We examined how parcel size affects wildfire transmission and partitioned the relative amounts of transmitted fire between human and natural ignitions. We estimated that 85 % of the total predicted wildfire activity, as measured by area burned, originates from four land tenures (Forest Service, Bureau of Land Management, private, and state lands) and 63 % of the …


Comparing Live-Capture Methods For Nutria: Single- Versus Multiple-Capture Cage Traps, Trevor Robert Sheffels, Mark D. Sytsma, Jacoby Carter, Jimmy D. Taylor Jan 2019

Comparing Live-Capture Methods For Nutria: Single- Versus Multiple-Capture Cage Traps, Trevor Robert Sheffels, Mark D. Sytsma, Jacoby Carter, Jimmy D. Taylor

Environmental Science and Management Faculty Publications and Presentations

Herbivory and burrowing by nutria (Myocastor coypus) cause substantial ecological and economic damage. Trapping is a common, effective practice for reducing nutria damage; however, trapping approaches must continually be adapted to keep pace with evolving animal welfare and ethical issues and to more effectively target pest species of interest. Our objective was to evaluate the efficacy of 2 nonlethal trap types for nutria: single-capture (SCT) and multi-capture (MCT) cage traps. We established 3 MCTs and 3 SCTs at each of 7 sites on a 10,500-ha mixed-use island located 15 km northwest of Portland, Oregon, USA. We pre-baited using …


Four-Fold Increase In Solar Forcing On Snow In Western U.S. Burned Forests Since 1999, Kelly E. Gleason, Joseph R. Mcconnell, Monica M. Arienzo, Nathan Chellman, Wendy M. Calvin Jan 2019

Four-Fold Increase In Solar Forcing On Snow In Western U.S. Burned Forests Since 1999, Kelly E. Gleason, Joseph R. Mcconnell, Monica M. Arienzo, Nathan Chellman, Wendy M. Calvin

Environmental Science and Management Faculty Publications and Presentations

Forest fires are increasing across the American West due to climate warming and fire suppression. Accelerated snow melt occurs in burned forests due to increased light transmission through the canopy and decreased snow albedo from deposition of light-absorbing impurities. Using satellite observations, we document up to an annual 9% growth in western forests burned since 1984, and 5 day earlier snow disappearance persisting for >10 years following fire. Here, we show that black carbon and burned woody debris darkens the snowpack and lowers snow albedo for 15 winters following fire, using measurements of snow collected from seven forested sites that …


Floodplains Provide Important Amphibian Habitat Despite Multiple Ecological Threats, Meredith Holgerson, Adam Duarte, Marc P. Hayes, Michael J. Adams, Julie A. Tyson, Keith A. Douville, Angela L. Strecker Jan 2019

Floodplains Provide Important Amphibian Habitat Despite Multiple Ecological Threats, Meredith Holgerson, Adam Duarte, Marc P. Hayes, Michael J. Adams, Julie A. Tyson, Keith A. Douville, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

Floodplain ponds and wetlands are productive and biodiverse ecosystems, yet they face multiple threats including altered hydrology, land use change, and non-native species. Protecting and restoring important floodplain ecosystems requires understanding how organisms use these habitats and respond to altered environmental conditions. We developed Bayesian models to evaluate occupancy of six amphibian species across 103 off-channel aquatic habitats in the Chehalis River floodplain, Washington State, USA. The basin has been altered by changes in land use, reduced river–wetland connections, and the establishment of non-native American bullfrogs (Rana catesbeiana = Lithobates catesbeianus) and centrarchid fishes, all of which we hypothesized could …