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Articles 1 - 11 of 11

Full-Text Articles in Physical Sciences and Mathematics

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 …


Final Report: Evaluation Of The Morphoedaphic Index And Sediment Diatoms For Inference Of Pre-European Settlement Total Phosphorus Concentration In Epa Region 10 Lakes, Rich Miller, Aaron Hook, Richard Petersen, Mark D. Sytsma Sep 2005

Final Report: Evaluation Of The Morphoedaphic Index And Sediment Diatoms For Inference Of Pre-European Settlement Total Phosphorus Concentration In Epa Region 10 Lakes, Rich Miller, Aaron Hook, Richard Petersen, Mark D. Sytsma

Center for Lakes and Reservoirs Publications and Presentations

Water quality in many Northwest lakes has declined over the past century due, in part, to increased anthropogenic nutrient loading (Edmonson and Lehman, 1981). Under the Clean Water Act, resource managers such as the Washington Department of Ecology, Oregon Department of Environmental Quality, and tribes are responsible for restoring and protecting the integrity of these waters. Targets for restoration or criteria for impairment are not well defined, however, and may naturally vary by geology, hydrology, morphometry, and climate.

One way to determine whether lakes are impaired and to identify restoration targets is to assess lake reference conditions (EPA 2000). Reference …


Street Trees In The Urban Forest Canopy: Portland, Oregon, Joseph Poracsky, David Banis Aug 2005

Street Trees In The Urban Forest Canopy: Portland, Oregon, Joseph Poracsky, David Banis

Geography Faculty Publications and Presentations

Attempts to identify the contribution of street trees to the overall urban forest of a city have been rare and lack consensus on how to measure that contribution – percentage of trees, percentage of canopy cover, or percentage of leaf area. The actual numeric values presented in the literature also vary over a broad range and often are based on estimates, extrapolations from aggregated data, or simply stated with no empirical data referenced. This study was undertaken to evaluate the contribution of street trees to canopy in Portland, Oregon. The study involved both visual and digital analysis of multi-band aerial …


Lake Whatcom Water Quality Model, Chris Berger Jul 2005

Lake Whatcom Water Quality Model, Chris Berger

Civil and Environmental Engineering Faculty Publications and Presentations

A water quality model of Lake Whatcom, Washington was developed as part of a Total Maximum Daily Load Study for the Washington Department of Ecology. Lake Whatcom is a large natural lake which is listed on the 1998 Washington State 303(d) list of waterbodies which do not meet the criterion for dissolved oxygen. Located next to the city of Bellingham, it is approximately 10 miles long and has a surface area of approximately 5000 acres and a maximum depth of over 100 meters. Eutrophication processes in the lake have been accelerated in recent years perhaps by the availability of nutrients …


Waldo Lake Research In 2004, Mark D. Sytsma, John Rueter, Richard Petersen, Roy Koch, Scott A. Wells, Michelle Wood, Yangdong Pan, Robert Leslie Annear, Aaron Hook, Laura Johnson, Rich Miller, Amanda Murphy, Terry Stoltz Jun 2005

Waldo Lake Research In 2004, Mark D. Sytsma, John Rueter, Richard Petersen, Roy Koch, Scott A. Wells, Michelle Wood, Yangdong Pan, Robert Leslie Annear, Aaron Hook, Laura Johnson, Rich Miller, Amanda Murphy, Terry Stoltz

Center for Lakes and Reservoirs Publications and Presentations

The Willamette National Forest has worked with Portland State University, Center for Lakes and Reservoirs (PSU) and the University of Oregon (UO) to investigate ecosystem changes, provide guidance on long-term monitoring methods, assess monitoring data, develop predictive water quality models, and conduct research that will lead to better protection and understanding of the Waldo Lake ecosystem. This report summarizes the second year of collaborative PSU-UO research at Waldo Lake. Research has focused on understanding physical, chemical and biological characteristics of Waldo Lake across a range of spatial and temporal scales. Research tasks that continued from 2003 into 2004 included temperature …


When Scoundrels Rule: Review Of The Last Refuge: Patriotism, Politics, And The Environment In An Age Of Terror, By David W. Orr, Robert Costanza May 2005

When Scoundrels Rule: Review Of The Last Refuge: Patriotism, Politics, And The Environment In An Age Of Terror, By David W. Orr, Robert Costanza

Institute for Sustainable Solutions Publications and Presentations

Book Review of The Last Refuge: Patriotism, Politics, and the Environment in an Age of Terror. David W. Orr. Island Press, Washington, DC, 2004.


Ecological Science And Sustainability For The 21st Century, Margaret A. Palmer, Emily S. Bernhardt, Elizabeth A. Chornesky, Scott L. Collins, Andrew P. Dobson, Clifford S. Duke, Barry D. Gold, Robert B. Jacobson, Sharon E. Kingsland, Rhonda H. Kranz, Michael J. Mappin, M. Luisa Martinez, Florenza Micheli, Jennifer L. Morse, Michael L. Pace, Mercedes Pascual, Stephen S. Palumbi, Oj Reichman, Alan R. Townsend, Monica G. Turner Feb 2005

Ecological Science And Sustainability For The 21st Century, Margaret A. Palmer, Emily S. Bernhardt, Elizabeth A. Chornesky, Scott L. Collins, Andrew P. Dobson, Clifford S. Duke, Barry D. Gold, Robert B. Jacobson, Sharon E. Kingsland, Rhonda H. Kranz, Michael J. Mappin, M. Luisa Martinez, Florenza Micheli, Jennifer L. Morse, Michael L. Pace, Mercedes Pascual, Stephen S. Palumbi, Oj Reichman, Alan R. Townsend, Monica G. Turner

Environmental Science and Management Faculty Publications and Presentations

Ecological science has contributed greatly to our understanding of the natural world and the impact of humans on that world. Now, we need to refocus the discipline towards research that ensures a future in which natural systems and the humans they include coexist on a more sustainable planet. Acknowledging that managed ecosystems and intensive exploitation of resources define our future, ecologists must play a greatly expanded role in communicating their research and influencing policy and decisions that affect the environment. To accomplish this, they will have to forge partnerships at scales and in forms they have not traditionally used. These …


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 …


Broad-Scale Non-Indigenous Species Monitoring Along The West Coast In National Marine Sanctuaries And National Estuarine Research Reserves, Catherine E. De Rivera, Greg Ruiz, Jeff Crooks, Kerstin Wasson, Steve Lonhart, Paul Fofonoff, Brian Steves, Steven S. Rumrill, Mary Sue Brancato, Scott Pegau, Doug Bulthuis, Rikke Kvist Preisler, Carl Schoch, Ed Bowlby, Andrew Devogelaere, Maurice Crawford, Steve Gittings, Anson Hines, Lynn Takata, Kristen Larson, Tami Huber, Anne Marie Leyman, Esther Collinetti, Tiffany Pascot, Suzanne Shull, Mary Anderson, Sue Powell Jan 2005

Broad-Scale Non-Indigenous Species Monitoring Along The West Coast In National Marine Sanctuaries And National Estuarine Research Reserves, Catherine E. De Rivera, Greg Ruiz, Jeff Crooks, Kerstin Wasson, Steve Lonhart, Paul Fofonoff, Brian Steves, Steven S. Rumrill, Mary Sue Brancato, Scott Pegau, Doug Bulthuis, Rikke Kvist Preisler, Carl Schoch, Ed Bowlby, Andrew Devogelaere, Maurice Crawford, Steve Gittings, Anson Hines, Lynn Takata, Kristen Larson, Tami Huber, Anne Marie Leyman, Esther Collinetti, Tiffany Pascot, Suzanne Shull, Mary Anderson, Sue Powell

Environmental Science and Management Faculty Publications and Presentations

Nonindigenous species have caused substantial environmental and economic damage to coastal areas. Moreover, the extent and impacts of nonindigenous species are increasing over time. To develop predictive models and to identify which areas should be targeted for impact mitigation or early detection, we need a basic foundation of knowledge about the spatial and temporal patterns of invasions. This project was developed because we lacked the necessary data to rigorously evaluate the patterns of coastal invasions. This collaborative project, between the Smithsonian Environmental Research Center, the National Estuarine Research Reserve System (NERRS) and the National Marine Sanctuary Program (NMSP), established a …


Response Of Sagebrush Steppe Species To Elevated Co2 And Soil Temperature, Melissa S. Lucash, Blake Farnsworth, William E. Winner Jan 2005

Response Of Sagebrush Steppe Species To Elevated Co2 And Soil Temperature, Melissa S. Lucash, Blake Farnsworth, William E. Winner

Environmental Science and Management Faculty Publications and Presentations

Elevated atmospheric CO2 may cause long-term changes in the productivity and species composition of the sagebrush steppe. Few studies, however, have evaluated the effects of increased CO2 on growth and physiology of species important to this ecosystem. Since the response of plants to elevated CO2 may be limited by environmental factors, soil temperature was also examined to determine if low soil temperatures limit CO2 response. To determine how CO2 and soil temperature affect the growth of species native to the sagebrush steppe, bottlebrush squirreltail [Elymus elymoides (Raf.) Swezey], Thurber needlegrass (Stipa thurberiana Piper), …


Temporal Variation In Nutrient Uptake Capacity By Intact Roots Of Mature Loblolly Pine, Melissa S. Lucash, J. Devereux Joslin, Ruth D. Yanai Jan 2005

Temporal Variation In Nutrient Uptake Capacity By Intact Roots Of Mature Loblolly Pine, Melissa S. Lucash, J. Devereux Joslin, Ruth D. Yanai

Environmental Science and Management Faculty Publications and Presentations

Nutrient uptake is generally thought to exhibit a simple seasonal pattern, but few studies have measured temporal variation of nutrient uptake capacity in mature trees. We measured net uptake capacity of K, NH+ 4, NO 3 −, Mg and Ca across a range of solution concentrations by roots of mature loblolly pine at Calhoun Experimental Forest in October 2001, July 2001, and April 2002. Uptake capacity was generally lowest in July; rates in October were similar to those in April. Across a range of concentrations, antecedent nutrient solution concentrations affected the temporal patterns in uptake in July but not in …