Other Environmental Sciences Commons^™

Microplastics Presence In Rhizophora Mangle Roots Throughout Fishponds And Open Coasts In Moloka'i, Hawaii, Mia Hackett

University Honors Theses

Microplastics (MP) are an emerging global contaminant that has drawn the attention of many researchers in the last few decades due to their growing environmental threats. Pieces of plastic smaller than 5 mm, they are specifically a high cause for concern in marine environments as their small size allows them to flow from inland into the ocean. Through this movement, MPs have been found in all marine ecosystems and ingested by hundreds of marine species often mistaking them for food. Labeled as one of the most threatened ecosystems, mangrove forests are already a large sink for a variety of contaminants …

Pfas In News Media: A Quantitative And Qualitative Analysis, Madison Haley

University Honors Theses

News media analysis allows for a greater understanding of mainstream public concerns throughout time. The history of US news articles covering per- and polyfluoroalkyl substances (PFAS), a class of chemicals posing increasing threats to public health and the environment, demonstrates Americans' awareness and perceptions of these chemicals over time. Based on the quantitative and qualitative analyses of PFAS-related national news articles in 2012-2022, this study discusses media representations and public perceptions of PFAS during the stated period. Results indicate an over 5700% increase in PFAS-related news articles over the 10-year timespan. Further, thematic analysis reveals that PFAS-related news articles are …

Ecological Investigations To Select Mitigation Options To Reduce Vehicle-Caused Mortality Of A Threatened Butterfly, Sara B. Zielin, Jalene Littlejohn, Catherine E. De Rivera, Winston P. Smith, Sandra L. Jacobson

Environmental Science and Management Faculty Publications and Presentations

Whereas roads that bisect habitat are known to decrease population size through animal-vehicle collisions or interruption of key life history events, it is not always obvious how to reduce such impacts, especially for flying organisms. We needed a quick, cost-efficient and effective way to determine how best to decrease vehicle-caused mortality while maintaining habitat connectivity for the federally listed Oregon silverspot butterfly, Speyeria zerene hippolyta. Therefore, we gathered targeted ecological information that informed selection of a mitigation option prior to implementation. We sampled butterfly behavior and environmental conditions along a highway and conducted a small-scale experiment along a decommissioned …

Getting Plant Conservation Right (Or Not): The Case Of The United States, Kayri Havens, Andrea T. Kramer, Edward O. Guerrant Jr.

Environmental Science and Management Faculty Publications and Presentations

Effective plant conservation includes addressing basic needs such as information about species distribution and rarity; research, management, education, and training capacity to mitigate threats facing threatened species; policy and funding to support continued capacity and conservation; and, ultimately, a public that understands and supports the importance of plants and the need for their conservation. Coordination of plant conservation efforts is also needed to ensure that resources and expertise are used in a strategic, efficient, and effective manner.We argue that no country is currently getting plant conservation right; plants are becoming increasingly rare around the world. Plants are often not fully …

Sampling For Effective Ex Situ Plant Conservation, Edward O. Guerrant Jr., Kayri Havens, Pati Vitt

Environmental Science and Management Faculty Publications and Presentations

Sampling a whole flora or any significant subset for ex situ conservation purposes is a complex, long-term proposition. Thus, it is important to consider what constitutes an adequate sample not only for all taxa as a whole but also for each taxon individually as well as how to strategically schedule collection over time. There are five basic sampling questions: from which species to collect, from how many and which populations, from how many and which individuals, how many and what kind of propagules to collect, and, finally, at what point is the desired sample size too great for a population …

Improving The Representation Of Roots In Terrestrial Models, Erica A.H. Smithwick, Melissa S. Lucash, M. Luke Mccormack, Gajan Sivandran

Environmental Science and Management Faculty Publications and Presentations

Root biomass, root production and lifespan, and root-mycorrhizal interactions govern soil carbon fluxes and resource uptake and are critical components of terrestrial models. However, limitations in data and confusions over terminology, together with a strong dependence on a small set of conceptual frameworks, have limited the exploration of root function in terrestrial models. We review the key root processes of interest to both field ecologists and modelers including root classification, production, turnover, biomass, resource uptake, and depth distribution to ask (1) what are contemporary approaches for modeling roots in terrestrial models? and (2) can these approaches be improved via recent …

Environmental Factors Influencing Diatom Communities In Antarctic Cryoconite Holes, Lee F. Stanish, Elizabeth A. Bagshaw, Diane M. Mcknight, Andrew G. Fountain, Martyn Tranter

Geology Faculty Publications and Presentations

Cryoconite holes are ice-bound habitats that can act as refuges for aquatic and terrestrial microorganisms on glacier surfaces. In the McMurdo Dry Valleys of Antarctica, these holes are often capped by an ice lid that prevents the exchange of material and gases with the surrounding atmosphere and aquatic environment. Diatoms have been documented in cryoconite holes, and recent findings suggest that these habitats may harbour a distinctive diatom flora compared to the surrounding aquatic environments. In this study, we examined diatom community composition in cryoconite holes and environmental correlates across three glaciers in Taylor Valley, Antarctica. The diatom communities were …

The Role Of Wood Microsites At Timberline-Alpine Meadow Borders For Conifer Regeneration, Adelaide Chapman Johnson

Dissertations and Theses

This research aimed to determine whether wood microsites ("nurse logs"), which are regeneration sites in Pacific Northwest (PNW) subalpine forests, supported regeneration at timberline-alpine meadow borders. Upward advance of forests and conifer invasion into alpine meadows, which may be occurring in conjunction with climate warming, have gained worldwide attention. Successful alpine meadow seedling regeneration depends on suitable substrate availability, or microsites, for seedling establishment. To better understand factors associated with wood microsite occurrence, mechanisms of wood input were determined and four specific hypotheses were posed to assess: (1) seedling density and seedling survival; (2) growing season length, summer mean growing …

Arsenic Mobility And Compositional Variability In High-Silica Ash Flow Tuffs, Courtney Beth Young Savoie

Dissertations and Theses

Volcanic rocks typically have only low to moderate arsenic concentrations, none-the-less, elevated levels of arsenic in ground waters have been associated with pyroclastic and volcaniclastic rocks and sediments in many parts of the world. The potential for arsenic leaching from these deposits is particularly problematic as they often comprise important water-bearing units in volcanic terrains. However, the role that chemical and mineralogical variations play in controlling the occurrence and mobility of arsenic from pyroclastic rocks is largely unexplored.

This study uses chemical and X-ray diffraction data to characterize and classify 49 samples of ash-flow tuffs, and 11 samples of tuffaceous …

Status Of Nutria (Myocastor Coypus) Populations In The Pacific Northwest And Development Of Associated Control And Management Strategies, With An Emphasis On Metropolitan Habitats, Trevor Robert Sheffels

Dissertations and Theses

The nutria (Myocastor coypus) is a semi-aquatic rodent native to South America that was introduced to the Pacific Northwest, USA, in the 1930s. Primary damage categories from this invasive species include burrowing and herbivory, resulting in habitat degradation. Nutria have become well-established in metropolitan habitats, and anecdotal information suggests the problem has increased in recent years. However, little regional research on the species has been conducted. The scope of this research, which emphasizes metropolitan habitats, includes three primary foci in relation to nutria populations in the Pacific Northwest: modeling habitat suitability, assessing activity and movement patterns, and identifying and managing …

Effects Of Molecular Structure Of The Oxidation Products Of Reactive Atmospheric Hydrocarbons On The Formation Of Secondary Organic Particulate Matter, Including The Effects Of Water, Negar Niakan

Dissertations and Theses

Organic aerosols have significant effects on human health, air quality and climate. Secondary organic aerosols (SOA) are produced by the oxidation of primary-volatile organic compounds (VOC). For example, α-pinene reacts with oxidants such as hydroxyl radical (OH), ozone (O₃), and nitrate radical (NO₃), accounting for a significant portion of total organic aerosol in the atmosphere. Experimental studies have shown that the oxidation process between α-pinene and ozone has the most significant impact in the formation of SOA (Hoffmann et al., 1997). Most of the models used to predict SOA formation, however, are limited in that they …

Characterization Of Nano-Scale Aluminum Oxide Transport Through Porous Media, Sasha Norien Norwood

Dissertations and Theses

Land application of biosolids has become common practice in the United States as an alternative to industrial fertilizers. Although nutrient rich, biosolids have been found to contain high concentrations of emerging contaminants (e.g. pharmaceuticals, personal care products) while containing a significant fraction of inorganic nano-scale colloidal materials such as oxides of iron, titanium, and aluminum.

Given their reactivity and small size, there are many questions concerning the potential migration of these nano-sized colloidal materials through the soil column and into our surface and groundwater bodies. Transport of emerging pollutants of concern through the soil column, at minimum, is impacted by …

The Value And Propriety Of Reintroduction As A Conservation Tool For Rare Plants, Edward O. Guerrant Jr.

Environmental Science and Management Faculty Publications and Presentations

Three recent reviews of reintroduction for conservation purposes, which draw on substantial and largely non-overlapping data sets, have come to strikingly different conclusions about its value. One concludes that “reintroduction is generally unlikely to be a successful conservation strategy as currently conducted.” Another that “…this review cannot conclusively comment on the effectiveness of re-introductions…” The third concludes there is “strong evidence in support of the notion that reintroduction, especially in combination with ex situ conservation, is a tool that can go a long way toward meeting the needs it was intended to address.” The argument over the conservation value of …

Site Selection By Migratory Shorebirds In Oregon Estuaries Over Broad And Fine Spatial Scales, Aileen Kilpatrick Miller

Dissertations and Theses

Many migratory shorebirds rely on estuaries as stop-over sites to refuel during migration, and the loss of stop-over sites is a primary threat to shorebird populations on the West Coast of the United States (e.g. Calidris alpina pacifica, C. mauri). Conservation and research has focused on the largest of these sites; however, smaller estuaries also host thousands of migratory shorebirds. Furthermore, the reasons for site selection are largely unknown. Estuarine inter-tidal microhabitats are non-uniform and both abiotic and biotic factors may serve as predictors of whether an abundance of shorebirds will use a site. I investigated shorebird site selection on …

The Effects Of Utility Pole Placement And Characteristics On Pentachlorophenol Concentrations Entering Underground Injection Control (Uic) Devices: City Of Gresham, Oregon, Katie Bohnren

Environmental Science and Management Professional Master's Project Reports

Urbanization is causing increased amounts of stormwater runoff, while simultaneously decreasing the amount of pervious surface area for infiltration. Multiple priority pollutants have been identified in urban stormwater, including pentachlorophenol (PCP). PCP is often found in stormwater samples exceeding the Safe Drinking Water Act limit of 1μg/L and can cause human health issues with exposure over time. Treated wood utility poles are the major source of PCP in urban stormwater. With the use of underground injection control (UIC) devices as an alternative method to treat and dispose of stormwater, the potential exists for groundwater contamination of PCP. The City of …

Sustainability Education As A Framework For Enhancing Environmental Stewardship In Young Leaders: An Intervention At Tryon Creek Nature Day Camp, Andrea Nicole Lawrence

Dissertations and Theses

UNESCO established Sustainability Education as a top priority when it declared 2005 - 2014 to be the global decade for sustainability. Sustainability education can be implemented in outdoor programs such as nature summer camps in order to build environmental stewardship and ecological literacy in counselors and campers. This study sought to determine the extent to which an ecology and leadership training given to assistant counselors at Tryon Creek State Natural Area day camp achieved the goals of sustainability education--for the assistant counselors to learn about ecology, develop stewardship attitudes and behaviors toward the environment, and become positive role models for …

(Editorial) A Long Term View Of Rare Plant Reintroduction. A Response To Godefroid Et Al. 2011: How Successful Are Plant Reintroductions?, Matthew A. Albrecht, Edward O. Guerrant Jr., Joyce Maschinski, Kathryn Kennedy

Environmental Science and Management Faculty Publications and Presentations

This is an editorial response to Godefroidet al. (2011). How successful are plant species reintroductions? Biological Conservation 144, 672-682.

Introduction To Common Native And Potential Invasive Freshwater Plants In Alaska, Vanessa Howard Morgan, Mark Sytsma

Center for Lakes and Reservoirs Publications and Presentations

Freshwater aquatic plants are found in most lakes and rivers in Alaska. They range from tiny floating plants that can form mats on a lake surface to emergent plants growing two meters above the water. Aquatic plants are an important part of freshwater environments. They provide food and shelter for a wide variety of insects, fish, mammals, and birds; stabilize shorelines; and form an important link in nutrient cycles. To date, Alaska has had relatively few problems with invasive, non-native aquatic plants. However, invasive aquatic plants pose an increasing threat to human safety and the integrity of native aquatic communities. …

Nutrient Uptake By Intact And Disturbed Roots Of Loblolly Pine Seedlings, Melissa S. Lucash, Ruth D. Yanai, J. Devereux Joslin

Environmental Science and Management Faculty Publications and Presentations

Most measurements of nutrient uptake use either hydroponic systems or soil-grown roots that have been disturbed by excavation. The first objective of this study was to test how root excavation affects nitrate uptake. Rates of NO3− uptake by mycorrhizal loblolly pine (Pinus taeda L.) seedlings were measured in intact sand-filled columns, hydroponics, and disturbed sand-filled columns. Total nitrate uptake in intact sand-filled columns was higher than in disturbed columns, indicating that disturbance lowers uptake. Transferring plants from the sand-filled columns to hydroponics had little effect on NO3− uptake beyond delaying uptake for an hour. The second objective of this study …

Estimating Nutrient Uptake By Mature Tree Roots Under Field Conditions: Challenges And Opportunities, Melissa S. Lucash, Dave M. Eissenstat, J. Devereux Joslin, Karis J. Mcfarlane, Ruth D. Yanai

Environmental Science and Management Faculty Publications and Presentations

Nutrient uptake by roots of mature trees is difficult to measure accurately under field conditions using existing methods. In this review, we discuss current techniques for measuring uptake at the root surface including excised roots, isotopic tracers, autoradiography, depletion, and lysimeters. Although these methods have provided many insights, each has drawbacks. Estimates of uptake are affected by the sampling scheme, experimental conditions, whether roots are excised or not, concentrations of ions, and the rate of efflux of ions. Microbes and mycorrhizas can also affect estimates of uptake. A greater focus on methods development is critical to advancing our understanding of …

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 …

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 …

A Study Of Oxygen Precipitation In Heavily Doped Silicon, Robert Kurt Graupner

Dissertations and Theses

Gettering of impurities with oxygen precipitates is widely used during the fabrication of semiconductors to improve the performance and yield of the devices. Since the effectiveness of the gettering process is largely dependent on the initial interstitial oxygen concentration, accurate measurements of this parameter are of considerable importance. Measurements of interstitial oxygen following thermal cycles are required for development of semiconductor fabrication processes and for research into the mechanisms of oxygen precipitate nucleation and growth. Efforts by industrial associations have led to the development of standard procedures for the measurement of interstitial oxygen in wafers. However practical oxygen measurements often …