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Full-Text Articles in Physical Sciences and Mathematics

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

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

Environmental Science and Management Faculty Publications and Presentations

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


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

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

Environmental Science and Management Faculty Publications and Presentations

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


Do Corporate Owned Adaptive Learning Platforms Perpetuate Banking Style Learning? Integrating Technology For Activism Into Transformational Sustainability Education, Tina M. Garner Aug 2019

Do Corporate Owned Adaptive Learning Platforms Perpetuate Banking Style Learning? Integrating Technology For Activism Into Transformational Sustainability Education, Tina M. Garner

Leadership for Sustainability Education Comprehensive Papers

We live in a world that tends to be controlled by corporations. The public school system should be wary of the problems that corporate control has on education. Even though public schools should not have corporate influence, the fact remains that they do, and this perpetuates Freire's banking style learning. Through time, the corporate influence in education was through educational materials such as book sales. Since the decline of the use of books and the growth of the use of technologies, corporations have followed suit through the sales of Adaptive Learning Platforms. Through leveraging the technology which students enjoy using, …


The Fate Of Atmospherically Deposited Mercury In Mountain Lake Food Webs, And Implications For Fisheries Management, Ariana Martos Chiapella Aug 2019

The Fate Of Atmospherically Deposited Mercury In Mountain Lake Food Webs, And Implications For Fisheries Management, Ariana Martos Chiapella

Dissertations and Theses

Mountain lakes are an iconic feature of the landscape in the Mountain West. They hold significant ecological and cultural value, and are important sentinels of environmental change. Despite their pristine image, these remote waterbodies are subjected to numerous anthropogenic stressors. Mountain lakes are naturally fishless systems, but historical fish stocking has led to major changes in mountain lake food web structure, including declines of resident amphibians, large-bodied zooplankton, and emergent insect populations. Atmospherically deposited contaminants, such as mercury, can accumulate in mountain lake food webs, leading to relatively high levels in the fish relative to the water. Managing for these …


Rare, Threatened And Endangered Species Of Oregon (2019), Jimmy Kagan, Sue Vrilakas, Eleanor P. Gaines, Lindsey K. Wise, Michael Russell, Cayla Sigrah Jul 2019

Rare, Threatened And Endangered Species Of Oregon (2019), Jimmy Kagan, Sue Vrilakas, Eleanor P. Gaines, Lindsey K. Wise, Michael Russell, Cayla Sigrah

Institute for Natural Resources Publications

The Oregon Biodiversity Information Center (ORBIC) is part of the Institute for Natural Resources (INR) located at Portland State University (PSU). ORBIC maintains extensive databases of Oregon biodiversity, concentrating on rare and endangered plants, animals and ecosystems. Since its creation in 1979 as the Oregon Natural Heritage Program, ORBIC has been part of the Natural Heritage network. ORBIC is a constituent member of NatureServe, a non-profit organization with a mission to provide the scientific basis for effective conservation action. NatureServe and Oregon manage data using standards and protocols used across the U.S., Canada, and much of Latin America.

ORBIC has …


Sensors And Portable Instruments For Postharvest Agriculture, Ryan M. Lerud Jun 2019

Sensors And Portable Instruments For Postharvest Agriculture, Ryan M. Lerud

Dissertations and Theses

The sensing needs for the fresh produce industry can be split into two primary stages: during maturation in the field, also referred to as Precision Farming, and during storage and transport of the produce, or Postharvest Storage. This work seeks to improve the accuracy and reliability of commercially available electrochemical and spectroscopic sensors tailored to the sensing needs of the fresh produce industry. For electrochemical sensing, this study proposes the use of an inline filter to remove polar organic compounds, which can interfere with the readings of a platinum-based electrochemical sensor. A 50% improvement in measurement accuracy was achieved when …


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

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

Environmental Science and Management Faculty Publications and Presentations

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


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

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

Environmental Science and Management Faculty Publications and Presentations

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


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

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

Environmental Science and Management Faculty Publications and Presentations

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


Limited Sequence Diversity Within A Population Supports Prebiotic Rna Reproduction, Ryo Mizuuchi, Niles Lehman Jan 2019

Limited Sequence Diversity Within A Population Supports Prebiotic Rna Reproduction, Ryo Mizuuchi, Niles Lehman

Chemistry Faculty Publications and Presentations

The origins of life require the emergence of informational polymers capable of reproduction. In the RNA world on the primordial Earth, reproducible RNA molecules would have arisen from a mixture of compositionally biased, poorly available, short RNA sequences in prebiotic environments. However, it remains unclear what level of sequence diversity within a small subset of population is required to initiate RNA reproduction by prebiotic mechanisms. Here, using a simulation for template-directed recombination and ligation, we explore the effect of sequence diversity in a given population for the onset of RNA reproduction. We show that RNA reproduction is improbable in low …