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Terrestrial and Aquatic Ecology Commons

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Portland State University

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Full-Text Articles in Terrestrial and Aquatic Ecology

Willow Abundance And Condition Mapping In Rocky Mountain National Park, Eric M. Nielsen May 2023

Willow Abundance And Condition Mapping In Rocky Mountain National Park, Eric M. Nielsen

Institute for Natural Resources Publications

Riparian and wetland willow species have undergone serious declines in Rocky Mountain National Park as a consequence of a variety of environmental changes and, most recently, damage resulting from moose overpopulation. To address concerns about the long-term status of willows in the park, we developed remote sensing-based raster maps of riparian and wetland willow species presence, canopy cover percentage, canopy height, and leaf area index. All outputs were produced at 3-meter resolution, and represent willows as they existed in 2021. The mapping was performed via random forests classification and regression models trained on several hundred vegetation plots from a variety …


Representation Justice As A Research Agenda For Socio-Hydrology And Water Governance, Melissa Haeffner, Dana E. Hellman, Alida Cantor, Idowu Ajibade, Vinka Oyanedel-Craver, Maura Kelly, Laura Schifman, Lisa Weasel Aug 2021

Representation Justice As A Research Agenda For Socio-Hydrology And Water Governance, Melissa Haeffner, Dana E. Hellman, Alida Cantor, Idowu Ajibade, Vinka Oyanedel-Craver, Maura Kelly, Laura Schifman, Lisa Weasel

Environmental Science and Management Faculty Publications and Presentations

We propose representation justice as a theoretical lens for socio-hydrology and water governance studies. An exploratory survey of 496 water sector employees in the United States revealed that self-identifying females felt more strongly discriminated against due to their gender and other social factors, compared to self-identifying males. Responses unveiled how macro- and microaggressions impede career pathways to leadership positions and, therefore, representation. We identify ways in which socio-hydrology can benefit from a representation justice lens by considering the following: (1) how power and politics shape the composition of the water sector and decision-making processes; (2) how available quantitative data do …


Do Foliar Endophytes Matter In Litter Decomposition?, Emily R. Wolfe, Daniel J. Ballhorn Mar 2020

Do Foliar Endophytes Matter In Litter Decomposition?, Emily R. Wolfe, Daniel J. Ballhorn

Biology Faculty Publications and Presentations

Litter decomposition rates are affected by a variety of abiotic and biotic factors, including the presence of fungal endophytes in host plant tissues. This review broadly analyzes the findings of 67 studies on the roles of foliar endophytes in litter decomposition, and their effects on decomposition rates. From 29 studies and 1 review, we compiled a comprehensive table of 710 leaf-associated fungal taxa, including the type of tissue these taxa were associated with and isolated from, whether they were reported as endo- or epiphytic, and whether they had reported saprophytic abilities. Aquatic (i.e., in-stream) decomposition studies of endophyte-affected litter were …


The Role Of Warm, Dry Summers And Variation In Snowpack On Phytoplankton Dynamics In Mountain Lakes, Isabella A. Olesky, Whitney S. Beck, Roderick W. Lammers, Cara E. Steger, Codie Wilson, Kyle R. Christianson, Kim Vincent, Gunnar Forrest Johnson, Pieter T.J. Johnson, Jill S. Baron Jan 2020

The Role Of Warm, Dry Summers And Variation In Snowpack On Phytoplankton Dynamics In Mountain Lakes, Isabella A. Olesky, Whitney S. Beck, Roderick W. Lammers, Cara E. Steger, Codie Wilson, Kyle R. Christianson, Kim Vincent, Gunnar Forrest Johnson, Pieter T.J. Johnson, Jill S. Baron

Geology Faculty Publications and Presentations

Climate change is altering biogeochemical, metabolic, and ecological functions in lakes across the globe. Historically, mountain lakes in temperate regions have been unproductive because of brief ice-free seasons, a snowmelt-driven hydrograph, cold temperatures, and steep topography with low vegetation and soil cover. We tested the relative importance of winter and summer weather, watershed characteristics, and water chemistry as drivers of phytoplankton dynamics. Using boosted regression tree models for 28 mountain lakes in Colorado, we examined regional, intraseasonal, and interannual drivers of variability in chlorophyll a as a proxy for lake phytoplankton. Phytoplankton biomass was inversely related to the maximum snow …


Classification Of Native Vegetation Of Oregon - 2019, Jimmy Kagan, Rachel L. Brunner, John Christy Jan 2019

Classification Of Native Vegetation Of Oregon - 2019, Jimmy Kagan, Rachel L. Brunner, John Christy

Institute for Natural Resources Publications

This classification is an update of the 2004 classification of native vegetation of Oregon by Kagan, Christy, Murray and Titus. As before, this classification lists the native plant associations known to occur in Oregon, and includes both successional and climax vegetation types that were part of the presettlement landscape of Oregon and can still be found in the state. It serves as an index to the diversity, distribution and relative rarity of the state's native plant associations, and as a guide to their literature. Published and unpublished reports supported by quantitative data were the primary sources for the classification. In …


Exploring, Exploiting And Evolving Diversity Of Aquatic Ecosystem Models: A Community Perspective, Annette B.G. Janssen, George B. Arhonditsis, Arthur Beusen, Karsten Bolding, Louise Bruce, Jorn Bruggeman, Raoul-Marie Couture, Andrea S. Downing, J. Alex Elliott, Marieke A. Frassl, Gideon Gal, Daan J. Gerla, Matthew R. Hipsey, Fenjuan Hu, Stephen C. Ives, Jan H. Janse, Erik Jeppesen, Klaus D. Jöhnk, David Kneis, Xiangzhen Kong, Jan J. Kuiper, Moritz K. Lehmann, Carsten Lemmen, Deniz Özkundakci, Thomas Petzoldt, Karsten Rinke, Barbara J. Robson, René Sachse, Sebastiaan A. Schep, Martin Schmid, Huub Scholten, Sven Teurlincx, Dennis Trolle, Tineke A. Troost, Anne A. Van Dam, Luuk P.A. Van Gerven, Mariska Weijerman, Scott A. Wells, Wolf M. Mooij Dec 2015

Exploring, Exploiting And Evolving Diversity Of Aquatic Ecosystem Models: A Community Perspective, Annette B.G. Janssen, George B. Arhonditsis, Arthur Beusen, Karsten Bolding, Louise Bruce, Jorn Bruggeman, Raoul-Marie Couture, Andrea S. Downing, J. Alex Elliott, Marieke A. Frassl, Gideon Gal, Daan J. Gerla, Matthew R. Hipsey, Fenjuan Hu, Stephen C. Ives, Jan H. Janse, Erik Jeppesen, Klaus D. Jöhnk, David Kneis, Xiangzhen Kong, Jan J. Kuiper, Moritz K. Lehmann, Carsten Lemmen, Deniz Özkundakci, Thomas Petzoldt, Karsten Rinke, Barbara J. Robson, René Sachse, Sebastiaan A. Schep, Martin Schmid, Huub Scholten, Sven Teurlincx, Dennis Trolle, Tineke A. Troost, Anne A. Van Dam, Luuk P.A. Van Gerven, Mariska Weijerman, Scott A. Wells, Wolf M. Mooij

Civil and Environmental Engineering Faculty Publications and Presentations

Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity by comparing and combining different aspects of …


Coastal Sediment Elevation Change Following Anthropogenic Mangrove Clearing, Heather Lyn Hayden, Elise F. Granek Sep 2015

Coastal Sediment Elevation Change Following Anthropogenic Mangrove Clearing, Heather Lyn Hayden, Elise F. Granek

Environmental Science and Management Faculty Publications and Presentations

Coastal mangrove forests along tropical shorelines serve as an important interface between land and sea. They provide a physical buffer protecting the coastline from erosion and act as sediment “traps” catching terrestrial sediment, thus preventing smothering of subtidal coral reefs. Coastal development that removes mangrove habitat may impact adjacent nearshore coral reefs through sedimentation and nutrient loading. We examined differences in sediment elevation change between patches of open-coast intact and anthropogenically cleared red mangroves (Rhizophora mangle) on the east side of Turneffe Atoll, Belize, to quantify changes following mangrove clearing. Samples were collected over a 24 month period at five …


Increased Harbor Porpoise Mortality In The Pacific Northwest, Usa: Understanding When Higher Levels May Be Normal, Jessica L. Higgins, Stephen A. Raverty, Stephanie A. Norman, John Calambokidis, Joseph K. Gaydos, Deborah A. Duffield, Dyanna M. Lambourn, James M. Rice, Brad Hanson, Kristin Wilkinson, Steven J. Jeffries, Brent Norberg, Lynne Barre Jul 2015

Increased Harbor Porpoise Mortality In The Pacific Northwest, Usa: Understanding When Higher Levels May Be Normal, Jessica L. Higgins, Stephen A. Raverty, Stephanie A. Norman, John Calambokidis, Joseph K. Gaydos, Deborah A. Duffield, Dyanna M. Lambourn, James M. Rice, Brad Hanson, Kristin Wilkinson, Steven J. Jeffries, Brent Norberg, Lynne Barre

Biology Faculty Publications and Presentations

In 2006, a marked increase in harbor porpoise Phocoena phocoena strandings were reported in the Pacific Northwest of the USA, resulting in the declaration of an unusual mortality event (UME) for Washington and Oregon to facilitate investigation into potential causes. The UME was in place during all of 2006 and 2007, and a total of 114 porpoises stranded during this period. Responders examined 95 porpoises; of these, detailed necropsies were conducted on 75 animals. Here we review the findings related to this event and how these compared to the years immediately before and after the UME. Relatively equal numbers among …


Re-Envisioning Community-Wildfire Relations In The U.S. West As Adaptive Governance, Jesse B. Abrams, Melanie Knapp, Travis B. Paveglio, Autumn Ellison, Cassandra Moseley, Max Nielsen-Pincus, Matthew S. Carroll Jan 2015

Re-Envisioning Community-Wildfire Relations In The U.S. West As Adaptive Governance, Jesse B. Abrams, Melanie Knapp, Travis B. Paveglio, Autumn Ellison, Cassandra Moseley, Max Nielsen-Pincus, Matthew S. Carroll

Environmental Science and Management Faculty Publications and Presentations

Prompted by a series of increasingly destructive, expensive, and highly visible wildfire crises in human communities across the globe, a robust body of scholarship has emerged to theorize, conceptualize, and measure community-level resilience to wildfires. To date, however, insufficient consideration has been given to wildfire resilience as a process of adaptive governance mediated by institutions at multiple scales. Here we explore the possibilities for addressing this gap through an analysis of wildfire resilience among wildland-urban interface communities in the western region of the United States. We re-engage important but overlooked components of social-ecological system resilience by situating rural communities within …


Archaeological Data Provide Alternative Hypotheses On Pacific Herring (Clupea Pallasii) Distribution, Abundance, And Variability, Iain Mckechnie, Dana Lepofsky, Madonna L. Moss, Virginia L. Butler, Trevor J. Orchard, Gary Coupland, Frederick Foster, Megan Caldwell, Ken Lertzman Feb 2014

Archaeological Data Provide Alternative Hypotheses On Pacific Herring (Clupea Pallasii) Distribution, Abundance, And Variability, Iain Mckechnie, Dana Lepofsky, Madonna L. Moss, Virginia L. Butler, Trevor J. Orchard, Gary Coupland, Frederick Foster, Megan Caldwell, Ken Lertzman

Anthropology Faculty Publications and Presentations

Over the last century, Pacific herring, a forage fish of tremendous cultural, economic, and ecological importance, has declined in abundance over much of its range. We synthesize archaeological fisheries data spanning the past 10,000 y from Puget Sound in Washington to southeast Alaska to extend the ecological baseline for herring and contextualize the dynamics of modern industrial fisheries. While modern herring populations can be erratic and exhibit catastrophic declines, the archaeological record indicates a pattern of consistent abundance, providing an example of long-term sustainability and resilience in a fishery known for its modern variability. The most parsimonious explanation for the …


Rapid Change In Shallow Water Fish Species Composition In An Historically Stable Antarctic Environment, Bradley A. Buckley Mar 2013

Rapid Change In Shallow Water Fish Species Composition In An Historically Stable Antarctic Environment, Bradley A. Buckley

Biology Faculty Publications and Presentations

McMurdo Sound, Antarctica, is home to a unique marine biota with an ecology that has evolved in this frigid environment over millions of years. The region is one of the least disturbed, and possibly the last pristine, marine ecosystem on Earth. Here, the results of three seasons of fishing in the shallow nearshore waters of McMurdo Sound are reported. A shift in the composition of small fish species at one site, Inaccessible Island, has been observed in just five years. The shift in shallow water species composition occurred during a period that followed the maturation of a commercial fishery for …


Links From Mantle To Microbe At The Lau Integrated Study Site: Insights From A Back-Arc Spreading Center, Margaret K. Tivey, Erin Becker, Roxanne Beinart, Charles R. Fisher, Peter Girguis, Charles H. Langmuir, Peter J. Michael, Anna-Louise Reysenbach Mar 2012

Links From Mantle To Microbe At The Lau Integrated Study Site: Insights From A Back-Arc Spreading Center, Margaret K. Tivey, Erin Becker, Roxanne Beinart, Charles R. Fisher, Peter Girguis, Charles H. Langmuir, Peter J. Michael, Anna-Louise Reysenbach

Biology Faculty Publications and Presentations

The Lau Integrated Study Site (ISS) has provided unique opportunities for study of ridge processes because of its back-arc setting in the southwestern Pacific. Its location allows study of a biogeographical province distinct from those of eastern Pacific and mid-Atlantic ridges, and crustal compositions along the ridge lie outside the range of mid-ocean ridge crustal compositions. The Lau ISS is located above a subduction zone, at an oblique angle. The underlying mantle receives water and other elements derived from the downgoing lithospheric slab, with an increase in slab influence from north to south. Water lowers the mantle melting temperature and …


Greenhouse Gas Fluxes In Southeastern U.S. Coastal Plain Wetlands Under Contrasting Land Uses, Jennifer L. Morse, Marcelo Ardón, Emily S. Bernhardt Jan 2012

Greenhouse Gas Fluxes In Southeastern U.S. Coastal Plain Wetlands Under Contrasting Land Uses, Jennifer L. Morse, Marcelo Ardón, Emily S. Bernhardt

Environmental Science and Management Faculty Publications and Presentations

Whether through sea level rise or wetland restoration, agricultural soils in coastal areas will be inundated at increasing rates, renewing connections to sensitive surface waters and raising critical questions about environmental trade-offs. Wetland restoration is often implemented in agricultural catchments to improve water quality through nutrient removal. Yet flooding of soils can also increase production of the greenhouse gases nitrous oxide and methane, representing a potential environmental trade-off. Our study aimed to quantify and compare greenhouse gas emissions from unmanaged and restored forested wetlands, as well as actively managed agricultural fields within the North Carolina coastal plain, USA. In sampling …


Limits To Sexual Reproduction In Geothermal Bryophytes, Sarah M. Eppley, Todd N. Rosenstiel, Camille Brianne Graves, Estefanía Llaneza García Sep 2011

Limits To Sexual Reproduction In Geothermal Bryophytes, Sarah M. Eppley, Todd N. Rosenstiel, Camille Brianne Graves, Estefanía Llaneza García

Biology Faculty Publications and Presentations

Previous research suggests that while sexual reproduction generally increases with environmental stress it may decrease with extreme stress, at the edge of eukaryotic life. In this study, we explored the limits to sexual reproduction in an extremophile, bryophyte system to ultimately understand the processes that limit sexual reproduction. We used field data from geothermal sites at Lassen Volcanic National Park, California, to demonstrate that sexual reproduction, as measured by the number of sporophytes per shoot, decreases with increasing environmental stress. We found that the number of sporophytes per shoot is positively correlated with distance from geothermal features. When Pohlia nutans …


Multiple And Long-Term Effects Of An Introduced Predatory Crab, Catherine E. De Rivera, Edwin D. Grosholz, Gregory M. Ruiz May 2011

Multiple And Long-Term Effects Of An Introduced Predatory Crab, Catherine E. De Rivera, Edwin D. Grosholz, Gregory M. Ruiz

Environmental Science and Management Faculty Publications and Presentations

Despite the importance of invasions, few studies have explored their long-term consequences in marine systems or examined multiple types of population-level effects. Initial effects, however, may not persist over longer time frames; effects have been shown to wane in freshwater systems. We combined 14 yr of field surveys (1993 to 2006) with manipulative experiments to examine the potential for multiple effects of a nonindigenous crab Carcinus maenas on the native shore crab Hemigrapsus oregonensis over time in central California. H. oregonensis abundance was negatively correlated with C. maenas abundance. However, H. oregonensis abundance rebounded to pre-invasion levels once C. maenas …


The Aquarium Trade As An Invasion Pathway In The Pacific Northwest, Angela L. Strecker, Philip M. Campbell, Julian D. Olden Apr 2011

The Aquarium Trade As An Invasion Pathway In The Pacific Northwest, Angela L. Strecker, Philip M. Campbell, Julian D. Olden

Environmental Science and Management Faculty Publications and Presentations

The aquarium trade moves thousands of species around the globe, and unwanted organisms may be released into freshwaters, with adverse ecological and economic effects. We report on the first investigation of the ornamental pet trade as an invasion pathway in the Pacific Northwest region of the United States, where a moderate climate and a large human population present ample opportunities for the introduction and establishment of aquarium trade species. Results from a regional survey of pet stores found that the number of fish (n=400) and plant (n=124) species currently in the aquarium trade is vast. Pet stores import thousands of …


Structuring Expert Input For A Knowledge-Based Approach To Watershed Condition Assessment For The Northwest Forest Plan, Usa, Sean N. Gordon, Kirsten Gallo Jan 2011

Structuring Expert Input For A Knowledge-Based Approach To Watershed Condition Assessment For The Northwest Forest Plan, Usa, Sean N. Gordon, Kirsten Gallo

Institute for Sustainable Solutions Publications and Presentations

Assessments of watershed condition for aquatic and riparian species often have to rely on expert opinion because of the complexity of establishing statistical relationships among the many factors involved. Such expert-based assessments can be difficult to document and apply consistently over time and space. We describe and reflect on the process of developing a computer-based decision support application from expert judgments for assessing aquatic and riparian conditions over the 100,000 km2 managed by the US federal government under the Northwest Forest Plan. The decision support system helped structure and document the assessment process and provided consistency and transparency to the …


Northern Range Expansion And Coastal Occurrences Of The New Zealand Mud Snail Potamopyrgus Antipodarum (Gray, 1843) In The Northeast Pacific, Timothy Mathias Davidson, Valance E. F. Brenneis, Catherine E. De Rivera, Robyn Draheim, Graham E. Gillespie Oct 2008

Northern Range Expansion And Coastal Occurrences Of The New Zealand Mud Snail Potamopyrgus Antipodarum (Gray, 1843) In The Northeast Pacific, Timothy Mathias Davidson, Valance E. F. Brenneis, Catherine E. De Rivera, Robyn Draheim, Graham E. Gillespie

Environmental Science and Management Faculty Publications and Presentations

The New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) is a common invasive species in fresh and brackish water ecosystems in Europe, Australia, Japan, and North America. In some invaded habitats, P. antipodarum can reach high densities (over 500,000 snails m-2) and dominate the biomass of the benthos, leading to detrimental impacts to native biota and changes in ecosystem dynamics. We report the previously unpublished occurrence of P. antipodarum in thirteen fresh and brackish water systems adjacent to the Pacific coast of North America including a new northern range for P. antipodarum: Port Alberni, Vancouver Island, British …


Dispersal Limitation And Climate-Related Environmental Gradients Structure Microcrustacean Composition In Freshwater Lakes, Ellesmere Island, Canada, Angela L. Strecker, Rebecca Milne, Shelley E. Arnott Aug 2008

Dispersal Limitation And Climate-Related Environmental Gradients Structure Microcrustacean Composition In Freshwater Lakes, Ellesmere Island, Canada, Angela L. Strecker, Rebecca Milne, Shelley E. Arnott

Environmental Science and Management Faculty Publications and Presentations

Dramatic environmental change is expected in the Arctic, yet little is known about the occurrence and community composition of microcrustaceans in Arctic lakes and how this will be influenced by future environmental change. We sampled and calculated relative abundances of microcrustacean species in 54 lakes on Ellesmere Island, Canada. New species records on Ellesmere Island included Daphnia umbra, Tachidius discipes, and Artemeopsis stefanssoni. Daphnia middendorffiana/tenebrosa was the most common taxon and often dominated microcrustacean assemblages, likely a result of its pigmentation, which offers resistance to ultraviolet radiation. Species richness was positively associated with nutrients, dissolved organic carbon (DOC), temperature, calcium, …


Green Crab Control: A Removal Effort In A Shallow Central California Estuary, Amy A. Larson, C. E. De Rivera, G. M. Ruiz, E. D. Grosholz, Mark D. Sytsma Mar 2008

Green Crab Control: A Removal Effort In A Shallow Central California Estuary, Amy A. Larson, C. E. De Rivera, G. M. Ruiz, E. D. Grosholz, Mark D. Sytsma

Environmental Science and Management Faculty Publications and Presentations

Goal: To test the feasibility and effects of locally removing a well-established population of a marine organism with pelagic larvae. Removal of adult European green crabs (Carcinus maenas) from Bodega Harbor as a model system to develop and inform management options for eradication, rapid response, and control of marine invaders.


Invasive Predator, Bythotrephes, Has Varied Effects On Ecosystem Function In Freshwater Lakes, Angela L. Strecker, Shelley E. Arnott Jan 2008

Invasive Predator, Bythotrephes, Has Varied Effects On Ecosystem Function In Freshwater Lakes, Angela L. Strecker, Shelley E. Arnott

Environmental Science and Management Faculty Publications and Presentations

Bythotrephes longimanus is an invertebrate predator that has invaded the North American Great Lakes and a number of inland lakes, where it preys on crustacean zooplankton. We examined the effect of Bythotrephes on two measures of ecosystem function during a four month observational study of freshwater lakes on the boreal shield. Bythotrephes-invaded lakes had significantly lower epilimnetic zooplankton abundance and production compared to reference lakes. On average, Bythotrephes consumed 34% ofzooplankton production when it was present in lakes. There was some evidence of changes in the timing of zooplankton production, as well as shifts to cooler, less productive habitats, which …


Green Crab Management: Reduction Of A Marine Invasive Population, Catherine E. De Rivera, Edwin D. Grosholz, Greg Ruiz, Amy A. Larson, Rebecca L. Kordas, Mark Sytsma Jul 2007

Green Crab Management: Reduction Of A Marine Invasive Population, Catherine E. De Rivera, Edwin D. Grosholz, Greg Ruiz, Amy A. Larson, Rebecca L. Kordas, Mark Sytsma

Environmental Science and Management Faculty Publications and Presentations

The overall goal of this study is to develop and demonstrate the capacity for local eradication of adult Carcinus maenas, European green crabs. This represents a conceptual shift in development of management options to address established invasions in marine systems, extending and exploring the application of terrestrial successes in this area. Specifically, this project tests the effects of removing green crabs from Bodega Harbor on the green crab population and on native shore crabs eaten by green crabs.


Hydrodynamic Mediation Of Density-Dependent Growth And Adult-Juvenile Interactions Of A Spionid Polychaete, Brent T. Hentschel, Amy A. Larson Mar 2006

Hydrodynamic Mediation Of Density-Dependent Growth And Adult-Juvenile Interactions Of A Spionid Polychaete, Brent T. Hentschel, Amy A. Larson

Environmental Science and Management Faculty Publications and Presentations

Abstract We performed an experiment to test the effects of adult density on the growth rates of juvenile Polydora cornuta. Our experiment was performed in three identical counter-rotating annular flumes, each set to one of three different flow speeds for a period of 3 d (U 5mm = 3, 6, or 12 cm s-1 , where U5mm = velocity measured 5 mm above bottom). We implanted replicate vials containing a premeasured juvenile P. cornuta and either 0, 2, or 5 adults into a 2-cm layer of sediment in the flume. The relative growth rates of the juveniles …


Variation In The Response Of Crustacean Zooplankton Species Richness And Composition To The Invasive Predator Bythotrephes Longimanus, Angela L. Strecker, Shelley E. Arnott, Norman D. Yan, Robert Girard Jan 2006

Variation In The Response Of Crustacean Zooplankton Species Richness And Composition To The Invasive Predator Bythotrephes Longimanus, Angela L. Strecker, Shelley E. Arnott, Norman D. Yan, Robert Girard

Environmental Science and Management Faculty Publications and Presentations

The predacious invertebrate Bythotrephes longimanus has invaded >90 freshwater lakes in North America. There is some evidence that B. longimanus has a negative effect on summer zooplankton species richness; however, no study has examined the effect of B. longimanus throughout the ice-free season in more than one lake. We visited 10 invaded and 4 reference lakes every 2 weeks from May to September, collecting B. longimanus, crustacean zooplankton, and water chemistry samples. Composite samples were pooled across the study season for each lake. Bythotrephes longimanus significantly reduced cladoceran species richness, diversity, and abundance, and the total zooplankton community also exhibited …


Impact Of Bythotrephes Invasion On Zooplankton Communities In Acid-Damaged And Recovered Lakes On The Boreal Shield, Angela L. Strecker, Shelley E. Arnott Oct 2005

Impact Of Bythotrephes Invasion On Zooplankton Communities In Acid-Damaged And Recovered Lakes On The Boreal Shield, Angela L. Strecker, Shelley E. Arnott

Environmental Science and Management Faculty Publications and Presentations

Invasive species introductions into freshwater ecosystems have had a multitude of effects on aquatic communities. Few studies, however, have directly compared the impact of an invader on communities with contrasting structure. Historically high levels and subsequent reductions of acid deposition have produced landscapes of lakes of varying acidity and zooplankton communitystructure. We conducted a 30-day enclosure experiment in Killarney Provincial Park, Ontario, Canada, to test the effects ofBythotrephes longimanus, an invasive invertebrate predator, on two contrasting zooplankton communities at different stages of recovery from acidification: recovered and acid damaged. Bythotrephes significantly decreased zooplankton biomass and abundance in both communities but …


Biotic Resistance To Invasion: Native Predator Limits Abundance And Distribution Of An Introduced Crab, Catherine E. De Rivera, Greg M. Ruiz, Anson Hines, Paul Jivoff Jan 2005

Biotic Resistance To Invasion: Native Predator Limits Abundance And Distribution Of An Introduced Crab, Catherine E. De Rivera, Greg M. Ruiz, Anson Hines, Paul Jivoff

Environmental Science and Management Faculty Publications and Presentations

Introduced species frequently escape the natural enemies (predators, competitors, and parasites) that limit their distribution and abundance in the native range. This reduction in native predators, competitors, and parasites may result in ecological release in the introduced range. However, biological interactions also can limit the establishment and spread of nonnative populations. The extent to which such biotic resistance occurs is poorly resolved, especially for marine ecosystems. Here we test whether a native predator, the blue crab Callinectes sapidus, affects the abundance and geographic range of the introduced European green crab Carcinus maenas in eastern North America. Both crab species …


Projecting Range Expansion Of Invasive European Green Crabs (Carcinus Maenas) To Alaska: Temperature And Salinity Tolerance Of Larvae, Anson Hines, Greg Ruiz, Natasha Gray Hitchcock, Catherine E. De Rivera Feb 2004

Projecting Range Expansion Of Invasive European Green Crabs (Carcinus Maenas) To Alaska: Temperature And Salinity Tolerance Of Larvae, Anson Hines, Greg Ruiz, Natasha Gray Hitchcock, Catherine E. De Rivera

Environmental Science and Management Faculty Publications and Presentations

The European Green Crab (Carcinus maenas) is a global invader, successfully colonizing many world regions and having significant ecological and economic impacts. The Green Crab colonized western North America in the late 1980s, spreading primarily northward from the initial establishment in San Francisco Bay to several other bays in northern California, Oregon, and Washington. Initial analysis, based largely upon temperature tolerance of postlarval crabs, suggests Green Crabs will continue to spread and become established throughout much of Alaska. However, establishment of self-sustaining populations in Alaska may be restricted by environmental conditions for reproduction and larval development, instead of the broad …


Reconnaissance Of Pharmaceutical Chemicals In Urban Streams Of The Tualatin River Basin, Oregon, 2002, Stewart A. Rounds, Micelis C. Doyle, Patrick M. Edwards, Edward T. Furlong Jan 2002

Reconnaissance Of Pharmaceutical Chemicals In Urban Streams Of The Tualatin River Basin, Oregon, 2002, Stewart A. Rounds, Micelis C. Doyle, Patrick M. Edwards, Edward T. Furlong

Environmental Science and Management Faculty Publications and Presentations

A reconnaissance of pharmaceutical chemicals in urban streams of the Tualatin River basin was conducted in July 2002 in an effort to better understand the occurrence and distribution of such compounds, and to determine whether they might be useful indicators of human-related stream contamination. Of the 21 pharmaceutical chemicals and metabolites tested, only 6 (acetaminophen, caffeine, carbamazepine, codeine, cotinine, and sulfamethoxazole) were detected in filtered stream samples from 10 sites. The concentrations of most of the detected compounds were relatively low (less than 0.05 microgram per liter). The most frequently detected compounds were cotinine (a nicotine metabolite, 8 of 10 …


Acorn Foraging As A Means To Explore Human Energetics And Forge Connections To Local Forests, Jeffrey J. Gerwing, Pamela Lockwood, Christopher Uhl Apr 1999

Acorn Foraging As A Means To Explore Human Energetics And Forge Connections To Local Forests, Jeffrey J. Gerwing, Pamela Lockwood, Christopher Uhl

Environmental Science and Management Faculty Publications and Presentations

Jeffrey Gerwing, Pamela Lockwood, and Christopher Uhl describe a rather unusual ecology laboratory/field exercise that utilizes abundant oak habitats of central Pennsylvania. For those readers not blessed with an abundant supply of oaks nearby, perhaps other species could be substituted. The exercise is unusual in two ways. It offers a new undergraduate ecology activity, and it offers opportunities for students to relate other disciplines to their science course.

In "the good old days" of higher education each discipline offered its menu of courses and expected students to make appropriate connections among the courses of their major, minor, and general education. …


Final Environmental Impact Statement For The Bal'diyaka Interpretive Center At Gregory Point On The Oregon Coast In Coos County, Joseph A. Maser Jan 1996

Final Environmental Impact Statement For The Bal'diyaka Interpretive Center At Gregory Point On The Oregon Coast In Coos County, Joseph A. Maser

Environmental Science and Management Faculty Publications and Presentations

The Confederated Tribes of Coos, Lower Umpqua and Siuslaw Indians, in partnership with the Coos Bay District of the Bureau of Land Management (BLM) are proposing to construct and operate an interpretive center near or on the South Coast of Oregon, near Coos Bay. The Bal'diyaka Interpretive Center is envisioned to contain a 51,000 square foot main building, a recreated coastal Indian village, an ethnobotanical interpretive trail, vehicular circulation and parking, and utilities infrastructure.

This Environmental Impact Statement analyzes four alternatives for this proposed interpretive center. The proposed action of the BLM would locate the Bal'diyaka Interpretive Center on Gregory …