Environmental Monitoring Commons^™

Phenotypic Plasticity Of Invasive Spartina Densiflora (Poaceae) Along A Broad Latitudinal Gradient On The Pacific Coast Of North America, Jesus M. Castillo, Brenda J. Grewall, Andrea Pickart, Alejandro Bortolus, Carlos Pena, Enrique Figueroa, Mark D. Sytsma

Environmental Science and Management Faculty Publications and Presentations

Premise of the study: Phenotypic acclimation of individual plants and genetic differentiation by natural selection within invasive populations are two potential mechanisms that may confer fitness advantages and allow plants to cope with environmental variation. The invasion of Spartina densiflora across a wide latitudinal gradient from California (USA) to British Columbia (Canada) provides a natural model system to study the potential mechanisms underlying the response of invasive populations to substantial variation in climate and other environmental variables.

Methods: We examined morphological and physiological leaf traits of Spartina densiflora plants in populations from invaded estuarine sites across broad latitudinal and climate …

Fish Species Introductions Provide Novel Insights Into The Patterns And Drivers Of Phylogenetic Structure In Freshwaters, Angela L. Strecker, Julian D. Olden

Environmental Science and Management Faculty Publications and Presentations

Despite long-standing interest of terrestrial ecologists, freshwater ecosystems are a fertile, yet unappreciated, testing ground for applying community phylogenetics to uncover mechanisms of species assembly. We quantify phylogenetic clustering and overdispersion of native and non-native fishes of a large river basin in the American Southwest to test for the mechanisms (environmental filtering versus competitive exclusion) and spatial scales influencing community structure. Contrary to expectations, non-native species were phylogenetically clustered and related to natural environmental conditions, whereas native species were not phylogenetically structured, likely reflecting human-related changes to the basin. The species that are most invasive (in terms of ecological impacts) …

Effect Of Reducing Maximum Cycle Length On Roadside Air Quality And Travel Times On A Corridor In Portland, Or, Christine M. Kendrick, David Urowsky, Willie Rotich, Peter Koonce, Linda Acha George

Environmental Science and Management Faculty Publications and Presentations

The Sydney Coordinated Adaptive Traffic System (SCATS), an adaptive signal system designed to reduce congestion, has been installed on a heavily trafficked roadway in Portland, OR. In addition to traffic performance metrics, we are investigating how this system affects roadway emissions of air pollutants. A twenty-second reduction to maximum cycle length was proposed for the SCATS system to address pedestrian delay concerns. A two-week trial period with this reduced cycle length was implemented. Travel times and roadside air pollution concentrations were monitored throughout this study period and compared to before and after periods with the current maximum cycle length. Average …

Effects Of Water Development On Arid Land Freshwater Ecosystems, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

This presentation focuses on the Columbia Basin Project

Emerging Contaminants In Oregon Coastal Waters: Hotspots, Landscape Drivers And Synergistic Effects On Bivalves, Elise F. Granek, William Fish, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

This presentation focuses on the following research questions:

• Types and levels of contaminants of emerging concern (CECs) in Oregon’s coastal ocean?
• Levels of CECs in native and commercial oysters?
• Ecological effects (growth, reproductive output, etc.) of these contaminants in marine bivalves?

Portland-Vancouver Ultra-Ex: Evaluating Relationships Between Governance And Environmental Quality In Urban Ecosystems, J. Alan Yeakley, Sally Duncan, Steve Bollens, Connie P. Ozawa, Vivek Shandas, Heejun Chang, Marion Dresner, Sean N. Gordon, John A. Harrison, Jeffrey D. Kline, Anita T. Morzillo, Noelwah R. Netusil, Gretchen Rollwagen-Bollens, Mark Stephan, Paul R. Thiers

Environmental Science and Management Faculty Publications and Presentations

The Portland-Vancouver Urban Long Term Research Area (ULTRA-Ex) is a multidisciplinary project aimed at understanding the feedbacks between human and natural systems in urban settings. The ULTRA-Ex project is seeking to answer the overarching question: How do human governance and biophysical systems respond interactively to both press and pulse disturbances in urban socio-ecological systems?

This presentation provides early observations and findings from the PV ULTRA-Ex project.

Divergent Carbon Dynamics Under Climate Change In Forests With Diverse Soils, Tree Species, And Land Use Histories, Robert M. Scheller, Alec M. Kretchun, Steve Van Tuyl, Kenneth L. Clark, Melissa S. Lucash, John Hom

Environmental Science and Management Faculty Publications and Presentations

Accounting for both climate change and natural disturbances—which typically result in greenhouse gas emissions—is necessary to begin managing forest carbon sequestration. Gaining a complete understanding of forest carbon dynamics is, however, challenging in systems characterized by historic over-utilization, diverse soils and tree species, and frequent disturbance. In order to elucidate the cascading effects of potential climate change on such systems, we projected forest carbon dynamics, including soil carbon changes, and shifts in tree species composition as a consequence of wildfires and climate change in the New Jersey pine barrens (NJPB) over the next 100 years. To do so, we used …

Using Environmental Variables And Soil Processes To Forecast Denitrification Potential And Nitrous Oxide Fluxes In Coastal Plain Wetlands Across Different Land Uses, Jennifer L. Morse, Marcelo Ardón, Emily S. Bernhardt

Environmental Science and Management Faculty Publications and Presentations

We examined relationships between denitrification (DNF) and nitrous oxide (N2O) fluxes and potentially important chemical and physical predictors to build a predictive understanding of gaseous N losses from coastal plain wetlands. We collected soil, gas, and pore water samples from 48 sampling locations across a large (440 ha) restored wetland, an adjacent drained agricultural field, and nearby forested wetlands every two months over two years. In summer and fall 2007, we measured soil DNF potential (21.6-3560 mg N m-3 d-1) and N2O efflux (-4.36-8.81 mg N m -2 d-1), along with 17 predictor variables. We developed statistical models for the …

An Individual-Based Process Model To Simulate Landscape-Scale Forest Ecosystem Dynamics, Rupert Seidi, Werner Rammer, Robert M. Scheller, Thomas A. Spies

Environmental Science and Management Faculty Publications and Presentations

Forest ecosystem dynamics emerges from nonlinear interactions between adaptive biotic agents (i.e., individual trees) and their relationship with a spatially and temporally heterogeneous abiotic environment. Understanding and predicting the dynamics resulting from these complex interactions is crucial for the sustainable stewardship of ecosystems, particularly in the context of rapidly changing environmental conditions. Here we present iLand (the individual-based forest landscape and disturbance model), a novel approach to simulating forest dynamics as an emergent property of environmental drivers, ecosystem processes and dynamic interactions across scales. Our specific objectives were (i) to describe the model, in particular its novel approach to simulate …

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 …

A New Model For Simulating Climate Change And Carbon Dynamics In Forested Landscapes, Caren C. Dymond, Robert M. Scheller, Sarah Beukema

Environmental Science and Management Faculty Publications and Presentations

Journal of Ecosystems & Management vol. 13 no. 2 2012 news brief .

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 …

The Sociology Of Landowner Interest In Restoring Fire-Adapted, Biodiverse Habitats In The Wildland-Urban Interface Of Oregon's Willamette Valley Ecoregion, Max Nielsen-Pincus

Environmental Science and Management Faculty Publications and Presentations

In many parts of the world, the combined effects of wildfire, climate change, and population growth in the wildland-urban interface pose increasing risks to both people and biodiversity. These risks are exemplified in western Oregon’s Willamette Valley Ecoregion, where population is projected to double by 2050 and climate change is expected to increase wildfire risk. Restoring elements of the region’s historic fire-adapted prairie, savanna, and woodland habitats may help to reduce future wildfire risk and help conserve the region’s threatened biodiversity. We report on a mail survey (n = 939) examining the socio-demographic factors influencing private landowners’ likelihood of restoring …

Increasing The Reliability Of Ecological Models Using Modern Software Engineering Techniques, Robert M. Scheller, Brian R. Sturtevant, Eric J. Gustafson, Brendan C. Ward, David J. Mladenoff

Environmental Science and Management Faculty Publications and Presentations

Modern software development techniques are largely unknown to ecologists. Typically, ecological models and other software tools are developed for limited research purposes, and additional capabilities are added later, usually in an ad hoc manner. Modern software engineering techniques can substantially increase scientific rigor and confidence in ecological models and tools. These techniques have the potential to transform how ecological software is conceived and developed, improve precision, reduce errors, and increase scientific credibility. We describe our re-engineering of the forest landscape model LANDIS (LANdscape DIsturbance and Succession) to illustrate the advantages of using common software engineering practices.

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, …

Environmental Controls On The Landscape-Scale Biogeography Of Stream Bacterial Communities, Noah Fierer, Jennifer L. Morse, Sean T. Berthrong, Emily S. Bernhardt, Robert B. Jackson

Environmental Science and Management Faculty Publications and Presentations

We determined the biogeographical distributions of stream bacteria and the biogeochemical factors that best explained heterogeneity for 23 locations within the Hubbard Brook watershed, a 3000-ha forested watershed in New Hampshire, USA. Our goal was to assess the factor, or set of factors, responsible for generating the biogeographical patterns exhibited by microorganisms at the landscape scale. We used DNA fingerprinting to characterize bacteria inhabiting fine benthic organic matter (FBOM) because of their important influence on stream nutrient dynamics. Across the watershed, streams of similar pH had similar FBOM bacterial communities. Streamwater pH was the single variable most strongly correlated with …

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), …

Sediment Nutrient Accumulation And Nutrient Availability In Two Tidal Freshwater Marshes Along The Mattaponi River, Virginia, Usa, Jennifer L. Morse, J. Patrick Megonigal, Mark R. Walbridge

Environmental Science and Management Faculty Publications and Presentations

Sediment deposition is the main mechanism of nutrient delivery to tidal freshwater marshes (TFMs). We quantified sediment nutrient accumulation in TFMs upstream and downstream of a proposed water withdrawal project on the Mattaponi River, Virginia. Our goal was to assess nutrient availability by comparing relative rates of carbon (C), nitrogen (N), and phosphorus (P) accumulated in sediments with the C, N, and P stoichiometries of surface soils and above ground plant tissues. Surface soil nutrient contents (0.60–0.92% N and 0.09–0.13% P) were low but within reported ranges for TFMs in the eastern US. In both marshes, soil nutrient pools and …

Relationships Between Needle Nitrogen Concentration And Photosynthetic Responses Of Douglas-Fir Seedlings To Elevated Co2 And Temperature, James D. Lewis, Melissa S. Lucash, David M. Olszyk, David T. Tingey

Environmental Science and Management Faculty Publications and Presentations

• Here we examined correlations between needle nitrogen concentration ([N]) and photosynthetic responses of Douglas-fir (Pseudotsuga menziesii) seedlings to growth in elevated temperatures and atmospheric carbon dioxide concentrations ([CO₂]).
• Seedlings were grown in sunlit, climate-controlled chambers at ambient or ambient+3.5^° C and ambient or ambient +180 μmol mol^-1 CO₂ in a full factorial design. Photosynthetic parameters and needle [N] were measured six times over a 21-month period.
• Needle [N] varied seasonally, and accounted for 30–50% of the variation in photosynthetic parameters. Across measurement periods, elevated temperature increased needle [N] by 26% and light-saturated …

Stomatal Responses Of Douglas-Fir Seedlings To Elevated Carbon Dioxide And Temperature During The Third And Fourth Years Of Exposure, James D. Lewis, Melissa S. Lucash, David M. Olszyk, David T. Tingey

Environmental Science and Management Faculty Publications and Presentations

Two major components of climate change, increasing atmospheric [CO₂] and increasing temperature, may substantially alter the effects of water availability to plants through effects on the rate of water loss from leaves. We examined the interactive effects of elevated [CO₂] and temperature on seasonal patterns of stomatal conductance (g_s), transpiration (E) and instantaneous transpiration efficiency (ITE) in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings. Seedlings were grown in sunlit chambers at either ambient CO₂ (AC) or ambient + 180 µmol mol^-1 CO₂ (EC), and at ambient temperature (AT) or ambient + 3.5° …

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 …

Seasonal Patterns Of Photosynthesis In Douglas Fir Seedlings During The Third And Fourth Year Of Exposure To Elevated Co2 And Temperature, James D. Lewis, Melissa S. Lucash, David M. Olszyk, David T. Tingey

Environmental Science and Management Faculty Publications and Presentations

The interactive effects of elevated atmospheric CO₂ and temperature on seasonal patterns of photosynthesis in Douglas fir (Psuedotsuga menziesii (Mirb.) Franco) seedlings were examined. Seedlings were grown in sunlit chambers controlled to track either ambient (~400 p.p.m.) CO₂ or ambient +200 p.p.m. CO₂, and either ambient temperature or ambient +4 °C. Light-saturated net photosynthetic rates were measured approximately monthly over a 21 month period. Elevated CO₂ increased net photosynthetic rates by an average of 21% across temperature treatments during both the 1996 hydrologic year, the third year of exposure, and the 1997 hydrologic year. Elevated …

Measurement Of Free Radicals Oh And Ho₂ In Los Angeles Smog, Linda Acha George, Thomas M. Hard, Robert J. O'Brien

Environmental Science and Management Faculty Publications and Presentations

Atmospheric free radicals hydroxyl and hydroperoxyl (OH and HO₂, collectively HOᵪ ) are the catalysts that cause secondary or photochemical air pollution. Chemical mechanisms for oxidant and acid formation, on which expensive air pollution control strategies are based, must accurately predict these radical concentrations. We have used the fluorescence assay with gas expansion (FAGE) technique to carry out the first simultaneous, in situ measurements of these two radicals in highly polluted air during the Los Angeles Free Radical Experiment. A complete suite of ancillary measurements was also made, including speciated hydrocarbons, carbon monoxide, aldehydes, nitric oxide, nitrogen dioxide, and ozone …

Internal Temperature Of Douglas-Fir Buds Is Altered At Elevated Temperature, Martha E. Apple, Melissa S. Lucash, David M. Olszyk, David T. Tingey, Donald L. Phillips

Environmental Science and Management Faculty Publications and Presentations

Pseudotsuga menziesii (Douglas-fir) saplings were grown in sun-lit controlled environment chambers at ambient or elevated (4°C above ambient) temperature. We measured internal temperatures of vegetative buds with thermocouple probes and compared temperatures of normal buds and abnormal buds with loosened, rosetted outer scales in elevated temperature chambers. The abnormal buds had higher and earlier peak daily temperatures than normal buds. Elevated temperature may influence the internal temperature of buds and contribute to the development of abnormal, rosetted buds with loosened outer scales. Abnormal bud development may alter branching patterns and allometry of Douglas-fir trees subjected to climatic change.

Morphogenesis Of Douglas Fir Buds Is Altered At Elevated Temperature But Not At Elevated Co2, Martha E. Apple, Melissa S. Lucash, David M. Olszyk, David T. Tingey

Environmental Science and Management Faculty Publications and Presentations

Global climatic change as expressed by increased CO₂ and temperature has the potential for dramatic effects on trees. To determine what its effects may be on Pacific Northwest forests, Douglas-fir (Pseudotsuga menziesii ) seedlings were grown in sun-lit controlled environment chambers at ambient or elevated (+4°C above ambient) temperature, and at ambient or elevated (+200 ppm above ambient) CO₂. In 1995–1996 and 1996–1997, elevated CO₂ had no effect on vegetative bud morphology, while the following unusual morphological characteristics were found with greater frequency at elevated temperature than at ambient: rosetted buds with reflexed and loosened outer …

Intercomparison Of Local Hydroxyl Measurements By Radiocarbon And Fage Techniques, Malcolm J. Campbell, Brad D. Hall, John C. Sheppard, Philip L. Utley, Robert J. O'Brien, Thomas M. Hard, Linda Acha George

Environmental Science and Management Faculty Publications and Presentations

A direct intercomparison of near-surface tropospheric HO concentration measurements by two different techniques was made in October–November 1992 at a rural site near Pullman, Washington. The atmosphere at the site is believed to contain low levels of anthropogenic pollution. The instruments' inlets were located at the same height (3.5 m) above the ground and were separated by 10 m along a line normal to the prevailing wind. Readings of the FAGE3 and radiocarbon instruments showed a high correlation (r² = 0.74) despite HO concentrations that were frequently near the detection limit of the instruments. An unweighted least squares regression shows …

Fage Determination Of Tropospheric Ho And Ho₂, Linda Acha George, Thomas M. Hard, Robert J. O'Brien

Environmental Science and Management Faculty Publications and Presentations

FAGE (fluorescence assay with gas expansion) was developed as a sensitive technique for the detection of low-concentration free radicals in the atmosphere. The application of FAGE to tropospheric hydroxyl (H0) and hydroperoxyl (H0₂) radicals has yielded calibrated measurements of both species in both clean air and highly polluted urban air. For HO calibration, a continuously stirred tank reactor provides a uniform external HO concentration, which can be measured by gas chromatography of an HO-reactive hydrocarbon. The aerodynamics of the air-sampling process has been modeled computationally, with results that agree with empirical observations of the effects of nozzle diameter on HO …

Carbon Monoxide In The Antarctic Atmosphere: Observations Of Decreasing Concentrations, M. A. K. Khalil, R. A. Rasmussen

Environmental Science and Management Faculty Publications and Presentations

Hydroxyl radicals remove hundreds, perhaps thousands, of organic gases from the atmosphere and are often regarded as am index of the oxidizing capacity of the Earth's atmosphere (Thompson 1992). In recent years, there have been growing concerns that, over the past century and now, human activities may be depleting hydroxyl concentrations by adding huge amounts of carbon monoxide and methane to the atmosphere. Reduction in the hydroxyl concentrations can then indirectly lead to more global warming, stratospheric ozone depletion, and other disturbances in atmospheric chemistry. Carbon monoxide (CO) is a key component in the determination of hydroxyl radical (OH) concentrations: …

Fage Measurements Of Tropospheric Ho With Measurements And Model Of Interferences, Thomas M. Hard, A. A. Mehrabzadeh, C. Y. Chan, Robert J. O'Brien

Environmental Science and Management Faculty Publications and Presentations

Ambient HO measurements by low-pressure laser-excited fluorescence with chemical modulation, and supporting ozone and water-vapor data, are presented for periods in May and August 1987. The observed peak daytime ambient HO concentrations in Oregon are in the range (2.5 to 8) times106 molecules cm⁻³ and show small negative offsets due to photochemical interference. Direct measurements of the interference at fixed [O₃] give the dependence on ambient [H₂O] and on the modulating reagent [isobutane]. At ambient [O₃]=30 p.p.b. and 10 torr H₂O, with excitation and detection at a total pressure of 4 torr, the net interference is equal to [HO]=-1.3times10⁶ molecule …

Diurnal Ho₂ Cycles At Clean Air And Urban Sites In The Troposphere, Thomas M. Hard, C. Y. Chan, A. A. Mehrabzadeh, Robert J. O'Brien

Environmental Science and Management Faculty Publications and Presentations

HO₂ concentrations have been determined at two Oregon sites for continuous periods of 36 to 48 hours, using fluorescence assay with gas expansion. At the sea level coastal site (45degN 124degW), NNW winds prevailed during daytime, and a point measurement of very low total nonmethane hydrocarbon concentration indicated the presence of remote tropospheric air of oceanic origin. At the urban site, HO₂ was determined during moderately low ozone pollution levels. At both sites, maximum daily [HO₂] was in the range of 1-2times10⁸ cm⁻³ under clear-sky conditions, with an estimated overall uncertainty of 40%.