2020 and 2021 brought the first reported outbreaks of salmonellosis epidemiologically linked to dry bulb onions in the United States. Outbreak investigations were not able to implicate a specific source of the contamination but speculated that contaminated water was a significant contributor. The Produce Safety Rule established minimum standards for...
In recent years, unoccupied aircraft systems (UAS) have become increasingly affordable and straightforward to incorporate in monitoring applications of forested ecosystems. This shift has facilitated interest in using these tools to monitor aspects of forest ecosystems including vegetation health, forest structure and composition, and potential habitat provided by these systems....
The Goose Lake Basin, situated on the border of Oregon and California, USA, faces significant challenges from drought, wildfire, and other environmental stressors. This region hosts numerous endemic fish species such as the Goose Lake redband trout (Oncorhynchus mykiss newberri), Goose Lake lamprey (Entosphenus sp.), Goose Lake tui chub (Siphateles...
Climate change will require families to withstand and adapt to potentially novel impacts in their forests, requiring both ecological and social resiliency. When facing a future of complex and uncertain conditions, family forest owners need more information on the magnitude and direction of change, which can be best accomplished through...
Escalating demand for organic blueberries has driven a significant expansion of northern highbush blueberry (NHB; Vaccinium corymbosum L.) production area. This expansion is particularly pronounced in regions of the Pacific Northwest where native soil conditions are sub-optimal for NHB, notably east of the Cascade Mountain Range of Oregon and Washington,...
Freshwater systems cycle carbon along a spatial and temporal biogeochemical continuum, across which ecosystem processes contribute to transformations of organic matter (OM). Various ecological constraints impact rates OM transformation and production and consumption of the energetic end of respiration, methane. Microbiological processing and complete reduction of carbon substrates to methane...
Traditional Ecological Knowledge (TEK) is a Knowledge-belief-practice system acquired through intergenerational direct and indirect observations representing past and current understandings of environments and integrates Indigenous value systems. TEK has become a popular topic recently as Indigenous stewarded lands contain more biodiversity and are more adaptable. It is critical for Indigenous...
In Oregon, the effects of climate change on agriculture are already being felt. In the Northwest, climate change impacts agricultural pest pressure, especially insects, whose life cycles are tied directly to weather and climate. The goal of this research was to record and analyze Oregon fruit and vegetable farmers’ relationships...
Early seral forests regenerating from stand-replacing disturbances provide unique habitat for many species in productive, temperate forest landscapes and contribute to supporting biodiversity. Population declines in some species associated with early seral forests have prompted concerns about the conservation of these habitats, particularly the characteristic structural and compositional complexity associated...
Oregon's estuaries are important ecosystems for scientific study. Consequently, knowledge of what research has been conducted helps us identify benchmarks and plan new projects. A comprehensive bibliography of published research, technical reports, local documents, and data sets is one means of recording this knowledge. For these reasons, the Guin Library...
Oregon's estuaries are important ecosystems for scientific study. Consequently, knowledge of what research has been conducted helps us identify benchmarks and plan new projects. A comprehensive bibliography of published research, technical reports, local documents, and data sets is one means of recording this knowledge. For these reasons, the Guin Library...
Oregon's estuaries are important ecosystems for scientific study. Consequently, knowledge of what research has been conducted helps us identify benchmarks and plan new projects. A comprehensive bibliography of published research, technical reports, local documents, and data sets is one means of recording this knowledge. For these reasons, the Guin Library...
Oregon's estuaries are important ecosystems for scientific study. Consequently, knowledge of what research has been conducted helps us identify benchmarks and plan new projects. A comprehensive bibliography of published research, technical reports, local documents, and data sets is one means of recording this knowledge. For these reasons, the Guin Library...
Oregon's estuaries are important ecosystems for scientific study. Consequently, knowledge of what research has been conducted helps us identify benchmarks and plan new projects. A comprehensive bibliography of published research, technical reports, local documents, and data sets is one means of recording this knowledge. For these reasons, the Guin Library...
Oregon's estuaries are important ecosystems for scientific study. Consequently, knowledge of what research has been conducted helps us identify benchmarks and plan new projects. A comprehensive bibliography of published research, technical reports, local documents, and data sets is one means of recording this knowledge. For these reasons, the Guin Library...
Oregon's estuaries are important ecosystems for scientific study. Consequently, knowledge of what research has been conducted helps us identify benchmarks and plan new projects. A comprehensive bibliography of published research, technical reports, local documents, and data sets is one means of recording this knowledge. For these reasons, the Guin Library...
Aromatic hydrocarbons represent a large class of environmental contaminants that have a broad range of structures, physicochemical properties, and toxicities. Arising from the burning of organic matter, particularly fossil fuels, they are both widespread and abundant in all environmental compartments. Both monoaromatic hydrocarbons (BTEX) and polycyclic aromatic hydrocarbons (PAHs) are...
This key to the bee genera of the Pacific Northwest provides dichotomous couplets which aid the user in identifying 60 genera of bees which occur or may occur in the region. The key architecture is based strongly on the key to the genera of North and Central America published in...
This species key to female bumble bees of the Pacific Northwest provides dichotomous couplets which aid the user in identifying 27 species which occur or have occurred historically, and may still be present in the region. The key architecture is based strongly on the key to species for females found...
This species key to male bumble bees of the Pacific Northwest provides dichotomous couplets which aid the user in identifying 27 species which occur or have occurred historically, and may still be present in the region. The key architecture is based strongly on the key to species for males found...
Metabolomics has recently gained momentum in biomolecule research and complements the genomics and proteomics research space. Metabolomics strives to detect, identify, and quantify all metabolites present in biological samples. In particular, biomolecular analysis using ultra-performance liquid chromatography combined with mass spectrometry (UPLC-MS) has become increasingly important for metabolomic analyses. Similarly,...
Anadromous Oncorhynchus mykiss (steelhead) express diverse migratory behaviors and life history strategies. Adult migration timing diversity within steelhead is often categorized into divergent early- and late-migration phenotypes. On the Rogue River in Oregon, adult steelhead return from the ocean during distinct early-summer, late-summer, and winter runs. Additionally, some juvenile steelhead...
Long-term, large-scale studies of meta-ecosystems provide critical information about how global change influences communities. In my dissertation, I analyzed data from studies encompassing 18 years (2006 – 2023) and over 1,000 km of coastline to investigate drivers of rocky intertidal community structure and dynamics. Specifically, I explored the roles of...
Wildfires can create alternative pathways for forest development, and wildfires have expanded in size, frequency, intensity, and severity across the western United States. The purpose of this paper is to compare forest development of a mature Douglas-fir forest in western Oregon across fire severities. Postburn field measurements were collected in...
Streams across the western United States are impaired from human alterations that have reduced freshwater habitat by simplifying channel complexity and disconnecting floodplains (Knox et al., 2022; Waples et al., 2008; Wohl, 2014). Climate change is likely to continue exacerbating these risks by warming summer surface stream temperatures (Crozier et...
Domestic violence (DV) is pervasive worldwide and has negative psychological effects that last a lifetime. Although DV is a problem that affects all societies, it is addressed through varied legal responses and with gaps in comprehension when examined through a cultural lens. The findings of these studies have the potential...
Despite ongoing initiatives and research efforts, the persistent underrepresentation of marginalized groups in Science, Technology, Engineering, and Math (STEM) disciplines in the U.S. has seen little improvement. This study posits that a fundamental change in teacher preparation can lead to more inclusive STEM learning environments. It centers on the development...
Coastal stream basins are of great importance to efforts aimed at refining our understanding of the earliest populations that inhabited the ancient Oregon coast. However, geomorphic responses to post-glacial sea level rise in these settings has produced depositional environments that destroy or deeply bury late Pleistocene and early Holocene-age archaeological...
This thesis examines the impacts of the COVID-19 pandemic on farms in the Willamette Valley. Using semi-structured interviews, this study analyzes the economic and social challenges created by the pandemic and the adaptation strategies farmers employed to build resilience within the food system. This study found that the farmers experienced...
The effects of fire on above-ground forest systems have been extensively studied. However, research on fire effects on belowground processes is lacking. While the soil microbiome is understood to be vital to conifer growth and regeneration, the complexity of soils means that research on the topic has largely been accomplished...
This thesis explores the challenges of monitoring stream hydrology in a warmer and wetter climate in the Kenai Peninsula (KP) and Prince William Sound (PWS) region of Southcentral Alaska, located on the traditional territories of the Dena’ina, Ahtna, Alutiiq/Sugpiaq, and Eyak People. The physical and climatological extremes of this region...
In the past fifty years, per- and polyfluoroalkyl substances (PFASs) have become alarming global pollutants. In 2019, the United States (U.S.) Environmental Protection Agency (EPA) ultimately classified them as emerging contaminants and established an action plan to address PFAS and protect public health through developing, identifying, monitoring, and remediating current...
In 2021, Oregon’s legislature passed House Bill 2021 with relative ease. House Bill 2021 is a mandate for the state’s two largest utilities to reduce carbon emissions from electricity generation on a decreasing scale, reaching 100% below baseline levels by 2040. This ambitious piece of legislation, meant to reduce the...
Water availability is a controlling factor in stream ecosystems with direct influences on habitat and aquatic ecosystem process, but little work has been done evaluating how biota respond to natural variations in low flow conditions during summer, and which biotic or abiotic features in the system may link most closely...
:
_____________________________________________________________________
Dana Warren, Mentor, representing Forest Ecosystems and Society, Fisheries, Wildlife, and
Oomycete and fungal pathogens threaten food, fiber, and forests around the world. With climate change, these pathogens are expected to emerge more frequently. Evolution can facilitate their emergence through mechanisms such as mutations that change or expand host range. Characterizing evolutionary mechanisms in plant pathogens will contribute to our ability...
Sound is a crucial aspect of the underwater environment for fishes – various species use sound to communicate, identify predators, navigate, and many other activities needed for survival in their habitat. Disruptions and disturbances in the natural soundscape can have important impacts on all these activities and are likely to...
Natural resources are essential to humanity. With the increase in global development in recent decades, people must monitor the state of the environment, whose disturbance has a more significant impact on society than before. However, conventional environmental monitoring is challenged in highly dynamic ecosystems and large areas. As a solution,...
Background: Against global health disparities and a shortfall of medical personnel, community health workers (CHWs) promise a solution based in lived experience and connection to the health system. To address global and upstream health determinants, CHW programs engage the perspectives of both the workers they employ and the communities they...
Managing invasive species is vital to preserving native species and maintaining the integrity of environments and ecological roles. Rats are one of the most prolific and intrusive invasive species that have successfully cohabitated with humans over centuries as we have expanded and advanced our societies. Thus, rats have historically been...
The Oregon coast faces complex environmental and social challenges, such as the threat of a regionally disastrous Cascadia Subduction Zone (CSZ) earthquake and tsunami. Researchers are united in their assertion that the CSZ is new, the region is due for a quake, and to mitigate this hazard society must collaborate...
Motivated by my own struggle to find identity and belonging as a transracial adoptee (TRA), I sought to fulfill two thesis purposes: 1) answer the question “How do transracial adoptees find and create identity and belonging in a contemporary United States culture and context?” and 2) establish a) a rationale...
Non-native ecosystem engineers, which modify the structure and function of their ecosystems, are often a particularly concerning and costly group of invasive species. Such organisms may have substantial impacts on ecosystem services, or the benefits that humans derive from their ecosystems. Many factors play a role in the invasion success...
Natural resources fields have historically been male-dominated, especially in terms of leadership. Forestry, and more specifically urban forestry, has displayed growth and development as women are being encouraged to enter the field and pursue goals of becoming leaders. One strategy for encouraging women leaders has been offering professional development opportunities....
Mass timber (MT) offers viable eco-conscious solutions within the building industry, with its high strength ratings, dimensional stability, light weight and renewable nature enhancing its status as a low carbon alternative to conventional building materials like steel and concrete. Moisture intrusion, coupled with the inherent organic nature of wood pose...
Production of fresh produce takes place outdoors, and therefore, is exposed to many routes of contamination (e.g., soil, contaminated water, manure, etc.) by human pathogens. Although precautions are taken to reduce this risk, pathogens can be regularly introduced to produce handling facilities. To manage the risk of cross-contamination from potentially...
Little is known about the fall and winter ecology of hibernating bats in western North America. Filling knowledge gaps for these populations has become more urgent with the westward spread of the white-nose syndrome, a disease that infects bats during hibernation. Due to the thermal requirements of the fungal pathogen...
Each NWR within the U.S. Fish and Wildlife Service (FWS) National Wildlife Refuge System (NWRS) provides landscapes that contribute to conservation of wildlife and the habitats they depend on at local, regional, and national levels. The Integrated Pest Management Plan (IPMP) for a given refuge is a guide to how...
Black stain root disease (BSRD) is a vascular wilt disease of conifers caused by three varieties of the native, insect-vectored fungal pathogen, Leptographium wageneri (L. wageneri var. wageneri, L. wageneri var. ponderosum, and L. wageneri var. pseudotsugae). Although morphological, physiological, and ecological characteristics differ among the three varieties of L....
Coastal landslides and erosion are major natural hazards resulting in unstable slopes, constituting immense challenges to modern infrastructure. Developing, maintaining, and performing risk assessments of infrastructure on, or close to, these hazards require a detailed understanding of the geophysical processes destabilizing the slope. These efforts start with the collection of...
The State of Oregon possesses a tumultuous relationship with the Earned Income Tax Credit (EITC) and currently experiences one of the lowest participation rates in the country despite attempting several policy reforms. The State of Washington has exhibited a comparatively similar relationship. However, it has adopted a distinctive policy supplementation...