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Portland State University

Environmental Science and Management Faculty Publications and Presentations

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Full-Text Articles in Physical Sciences and Mathematics

Discussion Of “Guiding Principles For Hydrologists Conducting Interdisciplinary Research And Fieldwork With Participants”, Melissa Haeffner May 2022

Discussion Of “Guiding Principles For Hydrologists Conducting Interdisciplinary Research And Fieldwork With Participants”, Melissa Haeffner

Environmental Science and Management Faculty Publications and Presentations

Rangecroft et al. (2021) offer a set of principles for conducting interdisciplinary research and fieldwork with participants from a hydrologist perspective. In this invited paper, I present some thoughts from a social scientist’s perspective, not to disagree with their points but to add to them. Specifically, I use my sociology background and interdisciplinary experiences to reflect on qualitative evaluative criteria, power dynamics in the scientific community, barriers to interdisciplinary research, and approaches to overcome obstacles. Individual researchers can educate themselves about other disciplines, and there are also opportunities for institutional change on the part of universities, funders, and …

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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 …

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Alpine Ice Evidence Of A Three-Fold Increase In Atmospheric Iodine Deposition Since 1950 In Europe Due To Increasing Oceanic Emissions, Michel Legrand, Joseph R. Mcconnell, Susanne Preunkert, Monica M. Arienzo, Nathan Chellman, Kelly E. Gleason, Tomás Sherwen, Mat J. Evans, Lucy J. Carpenter Nov 2018

Alpine Ice Evidence Of A Three-Fold Increase In Atmospheric Iodine Deposition Since 1950 In Europe Due To Increasing Oceanic Emissions, Michel Legrand, Joseph R. Mcconnell, Susanne Preunkert, Monica M. Arienzo, Nathan Chellman, Kelly E. Gleason, Tomás Sherwen, Mat J. Evans, Lucy J. Carpenter

Environmental Science and Management Faculty Publications and Presentations

Iodine is an important nutrient and a significant sink of tropospheric ozone, a climate-forcing gas and air pollutant. Ozone interacts with seawater iodide, leading to volatile inorganic iodine release that likely represents the largest source of atmospheric iodine. Increasing ozone concentrations since the preindustrial period imply that iodine chemistry and its associated ozone destruction is now substantially more active. However, the lack of historical observations of ozone and iodine means that such estimates rely primarily on model calculations. Here we use seasonally resolved records from an Alpine ice core to investigate 20th century changes in atmospheric iodine. After carefully considering …

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Bioassessment Of A Drinking Water Reservoir Using Plankton: High Throughput Sequencing Vs. Traditional Morphological Method, Wanli Gao, Zhaojin Chen, Yuying Li, Yangdong Pan, Jingya Zhu, Shijun Guo, Lanqun Hu, Jin Huang Jan 2018

Bioassessment Of A Drinking Water Reservoir Using Plankton: High Throughput Sequencing Vs. Traditional Morphological Method, Wanli Gao, Zhaojin Chen, Yuying Li, Yangdong Pan, Jingya Zhu, Shijun Guo, Lanqun Hu, Jin Huang

Environmental Science and Management Faculty Publications and Presentations

Drinking water safety is increasingly perceived as one of the top global environmental issues. Plankton has been commonly used as a bioindicator for water quality in lakes and reservoirs. Recently, DNA sequencing technology has been applied to bioassessment. In this study, we compared the effectiveness of the 16S and 18S rRNA high throughput sequencing method (HTS) and the traditional optical microscopy method (TOM) in the bioassessment of drinking water quality. Five stations reflecting different habitats and hydrological conditions in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia, were sampled May 2016. Non-metric multi-dimensional scaling (NMDS) analysis showed …

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Effects Of Water Level Increase On Phytoplankton Assemblages In A Drinking Water Reservoir, Yangdong Pan, Shijun Guo, Yuying Li, Wei Yin, Pengcheng Qi, Jainwei Shi, Lanqun Hu, Bing Li, Shengge Bi, Jingya Zhu Jan 2018

Effects Of Water Level Increase On Phytoplankton Assemblages In A Drinking Water Reservoir, Yangdong Pan, Shijun Guo, Yuying Li, Wei Yin, Pengcheng Qi, Jainwei Shi, Lanqun Hu, Bing Li, Shengge Bi, Jingya Zhu

Environmental Science and Management Faculty Publications and Presentations

Excessive water level fluctuation may affect physico-chemical characteristics, and consequently ecosystem function, in lakes and reservoirs. In this study, we assessed the changes of phytoplankton assemblages in response to water level increase in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia. The water level increased from a low of 137 m to 161 m in 2014 as a part of the South–North Water Diversion Project. Phytoplankton assemblages were sampled four times per year before, during and after the water level increase, at 10 sites. Environmental variables such as total nitrogen as well as phytoplankton biomass decreased after …

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Variation In Tussock Architecture Of The Invasive Cordgrass Spartina Densiflora Along The Pacific Coast Of North America, Jesus M. Castillo, Brenda J. Grewall, Andrea Pickart, Enrique Figueroa, Mark D. Sytsma Jul 2016

Variation In Tussock Architecture Of The Invasive Cordgrass Spartina Densiflora Along The Pacific Coast Of North America, Jesus M. Castillo, Brenda J. Grewall, Andrea Pickart, Enrique Figueroa, Mark D. Sytsma

Environmental Science and Management Faculty Publications and Presentations

Some introduced species spread rapidly beyond their native range and into novel habitats mediated by a high degree of phenotypic plasticity and/or rapid evolutionary responses. In this context, clonality has been described as a significant factor contributing to invasiveness. We studied the abiotic environment and the responses of different tussock architecture traits of the invasive cordgrass Spartina densiflora Brongn. (Poaceae). A common garden experiment and field studies of S. densiflora in salt marshes across a wide latitudinal gradient from California (USA) to British Columbia (Canada) provided a model system for an integrated study of the potential mechanisms underlying the response …

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Searching For Biogeochemical Hot Spots In Three Dimensions: Soil C And N Cycling In Hydropedologic Settings In A Northern Hardwood Forest, Jennifer L. Morse, S F. Werner, Cody P. Gillin, Christine L. Goodale, Scott W. Bailey, Kevin J. Mcguire, Peter M. Groffman May 2014

Searching For Biogeochemical Hot Spots In Three Dimensions: Soil C And N Cycling In Hydropedologic Settings In A Northern Hardwood Forest, Jennifer L. Morse, S F. Werner, Cody P. Gillin, Christine L. Goodale, Scott W. Bailey, Kevin J. Mcguire, Peter M. Groffman

Environmental Science and Management Faculty Publications and Presentations

Understanding and predicting the extent, location, and function of biogeochemical hot spots at the watershed scale is a frontier in environmental science. We applied a hydropedologic approach to identify (1) biogeochemical differences among morphologically distinct hydropedologic settings and (2) hot spots of microbial carbon (C) and nitrogen (N) cycling activity in a northern hardwood forest in Hubbard Brook Experimental Forest, New Hampshire, USA. We assessed variables related to C and N cycling in spodic hydropedologic settings (typical podzols, bimodal podzols, and Bh podzols) and groundwater seeps during August 2010. We found that soil horizons (Oi/Oe, Oa/A, and B) differed significantly …

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Convergent Surface Water Distributions In U.S. Cities, Meredith K. Steele, James B. Heffernan, Neil D. Bettez, Jeannine Cavender-Bares, Peter M. Groffman, J. Morgan Grove, Sharon J. Hall, Sarah E. Hobbie, Kelli L. Larson, Jennifer L. Morse, Christopher Neill, Kristen C. Nelson, Jarlath O'Neil-Dunne, Laura A. Ogden, Diane E. Pataki, Colin Polsky, Rinku Roy Chowdhury Feb 2014

Convergent Surface Water Distributions In U.S. Cities, Meredith K. Steele, James B. Heffernan, Neil D. Bettez, Jeannine Cavender-Bares, Peter M. Groffman, J. Morgan Grove, Sharon J. Hall, Sarah E. Hobbie, Kelli L. Larson, Jennifer L. Morse, Christopher Neill, Kristen C. Nelson, Jarlath O'Neil-Dunne, Laura A. Ogden, Diane E. Pataki, Colin Polsky, Rinku Roy Chowdhury

Environmental Science and Management Faculty Publications and Presentations

Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However,the scope and consequences of surface water redistribution at broad spatialscales are not well understood. We hypothesized that urbanization would lead to convergent surface water abundance and distribution: in other words, cities will gain or lose water such that they become more similar to each other than are their surrounding natural landscapes. Using a database of more than 1 million water bodies and 1 million km of streams, we compared the surface water of 100 US cities with …

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A Review Of Urban Water Body Challenges And Approaches: (1) Rehabilitation And Remediation, Robert M. Hughes, Susie Dunham, Kathleen G. Maas-Hebner, J. Alan Yeakley, Carl B. Schreck, Michael Harte, Nancy Molina, Clinton C. Shock, Victor W. Kaczynski, Jeff Schaeffer Jan 2014

A Review Of Urban Water Body Challenges And Approaches: (1) Rehabilitation And Remediation, Robert M. Hughes, Susie Dunham, Kathleen G. Maas-Hebner, J. Alan Yeakley, Carl B. Schreck, Michael Harte, Nancy Molina, Clinton C. Shock, Victor W. Kaczynski, Jeff Schaeffer

Environmental Science and Management Faculty Publications and Presentations

We review how urbanization alters aquatic ecosystems, as well as actions that managers can take to remediate urban waters. Urbanization affects streams by fundamentally altering longitudinal and lateral processes that in turn alter hydrology, habitat, and water chemistry; these effects create physical and chemical stressors that in turn affect the biota. Urban streams often suffer from multiple stressor effects that have collectively been termed an “urban stream syndrome,” in which no single factor dominates degraded conditions. Resource managers have multiple ways of combating the urban stream syndrome. These approaches range from whole-watershed protection to reach-scale habitat rehabilitation, but the prescription …

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Winter Climate Change Affects Growing-Season Soil Microbial Biomass And Activity In Northern Hardwood Forests, Jorge Durán, Jennifer L. Morse, Peter M. Groffman, John L. Campbell, Lynn M. Christenson, Charles T. Driscoll, Timothy J. Fahey, Melany C. Fisk, Mryon J. Mitchell, Pamela H. Templer Jan 2014

Winter Climate Change Affects Growing-Season Soil Microbial Biomass And Activity In Northern Hardwood Forests, Jorge Durán, Jennifer L. Morse, Peter M. Groffman, John L. Campbell, Lynn M. Christenson, Charles T. Driscoll, Timothy J. Fahey, Melany C. Fisk, Mryon J. Mitchell, Pamela H. Templer

Environmental Science and Management Faculty Publications and Presentations

Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity during the growing season. Soils from lower elevation plots, which accumulated less snow and experienced more soil temperature variability during the winter (and likely more freeze/thaw events), had less extractable inorganic nitrogen (N), lower rates of microbial N production via potential net N mineralization and nitrification, and higher …

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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 Jun 2012

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 …

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An Individual-Based Process Model To Simulate Landscape-Scale Forest Ecosystem Dynamics, Rupert Seidi, Werner Rammer, Robert M. Scheller, Thomas A. Spies Apr 2012

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 …

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Foliar Nutrient Concentrations Related To Soil Sources Across A Range Of Sites In The Northeastern United States, Melissa S. Lucash, Ruth D. Yanai, Joel D. Blum, B. B. Park Jan 2011

Foliar Nutrient Concentrations Related To Soil Sources Across A Range Of Sites In The Northeastern United States, Melissa S. Lucash, Ruth D. Yanai, Joel D. Blum, B. B. Park

Environmental Science and Management Faculty Publications and Presentations

Understanding the supply of nutrients from various soil sources and the sensitivity of tree species to soil nutrient availability is critical for predicting the effects of declines in base cations due to acid rain and forest harvesting on forest health and productivity. We collected soil samples from 19 sites in the northeastern United States, chemically analyzed them using a sequential extraction procedure, and compared them to the chemical composition of foliage of the dominant tree species. Concentrations of Ca and Mg in foliage were correlated with exchangeable Ca and Mg concentrations in the upper mineral soil; for most tree species …

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Phosphorus Export From A Restored Wetland Ecosystem In Response To Natural And Experimental Hydrologic Fluctuations, Marcelo Ardón, Shaena Montanari, Jennifer L. Morse, Martin W. Doyle, Emily S. Bernhardt Dec 2010

Phosphorus Export From A Restored Wetland Ecosystem In Response To Natural And Experimental Hydrologic Fluctuations, Marcelo Ardón, Shaena Montanari, Jennifer L. Morse, Martin W. Doyle, Emily S. Bernhardt

Environmental Science and Management Faculty Publications and Presentations

Wetland restoration is a commonly used approach to reduce nutrient loading to freshwater and coastal ecosystems, with many wetland restoration efforts occurring in former agricultural fields. Restored wetlands are expected to be effective at retaining or removing both nitrogen and phosphorus (P), yet restoring wetland hydrology to former agricultural fields can lead to the release of legacy fertilizer P. Here, we examined P cycling and export following rewetting of the Timberlake Restoration Project, a 440 ha restored riverine wetland complex in the coastal plain of North Carolina. We also compared P cycling within the restored wetland to two minimally disturbed …

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Similarity Of Nutrient Uptake And Root Dimensions Of Engelmann Spruce And Subalpine Fir At Two Contrasting Sites In Colorado, Melissa S. Lucash, Ruth D. Yanai, Karis J. Mcfarlane, Sarah E. Kulpa, Dustin M. Wood Oct 2009

Similarity Of Nutrient Uptake And Root Dimensions Of Engelmann Spruce And Subalpine Fir At Two Contrasting Sites In Colorado, Melissa S. Lucash, Ruth D. Yanai, Karis J. Mcfarlane, Sarah E. Kulpa, Dustin M. Wood

Environmental Science and Management Faculty Publications and Presentations

Nutrient uptake capacity is an important parameter in modeling nutrient uptake by plants. Researchers commonly assume that uptake capacity measured for a species can be used across sites. We tested this assumption by measuring the nutrient uptake capacity of intact roots of Engelmann spruce (Picea engelmanni Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) at Loch Vale Watershed and Fraser Experimental Forest in the Rocky Mountains of central Colorado. Roots still attached to the tree were exposed to one of three concentrations of nutrient solutions for time periods ranging from 1 to 96h, and solutions were analyzed for ammonium, …

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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 Sep 2007

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 …

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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), …

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Soil Moisture Gradients And Controls On A Southern Appalachian Hillslope From Drought Through Recharge, J. Alan Yeakley, W. T. Swank, L. W. Swift, G. M. Hornberger, H. H. Shugart Jan 1998

Soil Moisture Gradients And Controls On A Southern Appalachian Hillslope From Drought Through Recharge, J. Alan Yeakley, W. T. Swank, L. W. Swift, G. M. Hornberger, H. H. Shugart

Environmental Science and Management Faculty Publications and Presentations

Soil moisture gradients along hillslopes in humid watersheds, although indicated by vegetation gradients and by studies using models, have been difficult to confirm empirically. While soil properties and topographic features are the two general physio-graphic factors controlling soil moisture on hillslopes, studies have shown conflicting results regarding which factor is more important. The relative importance of topographic and soil property controls was examined in an upland forested watershed at the Coweeta Hydrologic Laboratory in the southern Appalachian mountains. Soil moisture was measured along a hillslope transect with a mesic-to-xeric forest vegetation gradient over a period spanning precipitation extremes. The hillslope …

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