Undergraduate Theses & Honors Theses

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Open Access
Variation in Bumble Bee Foraging Networks Across A Gradient of Forest Canopy
(University of Oregon, 2024-06) Metzger, Sam
Land use change, invasion of non-native species, and other modes of habitat loss contribute to native bee population declines. A key contribution to population decline may be a loss of nutritional resources, which can occur when landscapes have reduced floral diversity and abundance. Increasing floral resources may mitigate future declines and forest ecosystems may offer necessary food and nesting opportunities for native bees. However, it is unclear whether and how forest management practices influence the capacity of forests to fulfill these roles. Our research advances the field's understanding of bumble bee nutrition as a function of plant community structure by examining it within a forest ecosystem. To do this, we focused on foraging patterns of bumble bees across a gradient of canopy openness in the Oregon Coast Range. With the understanding that bumble bees prefer warm, sunny, fair-weathered spaces with abundant floral resources, we hypothesized (1) there would be a positive relationship between floral diet breadth and canopy openness. We further predicted (2) increased canopy cover would result in less floral richness, and greater niche overlap among bumble bee species. Our results support the first hypothesis for two of our most abundant species but not the third. Moreover, floral richness was indeed lower with greater canopy cover, but responses in niche overlap varied across our three most abundant species. This demonstrates that different bumble bees have varying responses in foraging behavior to forest canopy structure. This research provides information that could assist in conifer forest management practices to better provide for wild bumble bee community restoration and conservation.
Open Access
Drought Response of Plant Coexistence are Mediated by Arbuscular Mycorrhizal Fungi
(University of Oregon, 2024-06) Tavernier, Austyn
Climate change is predicted to alter interannual precipitation patterns and increase drought severity and frequency. Although plant ecologists are actively investigating the impacts of climate change, we still lack robust and generalizable predictions of future plant community dynamics in light of novel precipitation regimes. One of the most pressing obstacles for making these predictions is understanding how the many species in these communities, as well as the interactions between them, respond to drought. Among the more important biotic players in structuring herbaceous plant communities are arbuscular mycorrhizal fungi (AMF) which have been shown to contribute to plant responses to drought at both an individual and community level. However, the mechanisms of drought-dependent mycorrhizal effects on plant competition have yet to be empirically assessed. To explore how AMF may modify the effect of drought on plant competitive dynamics, we conducted a greenhouse competition experiment within a two-by-two factorial manipulation of soil moisture and AMF presence. We used the data from this experiment to parameterize population dynamic models for each species (Clarkia amoena, Collinsia grandiflora, and Plectritis congesta) within each treatment combination. We used posterior distributions of our parameter estimates to explore how mycorrhizae and drought singularly and interactively influenced species vital rates, interaction coefficients, and the niche and fitness differences underlying pairwise species coexistence. We found that intrinsic growth rates of species generally decreased with drought and increased with AMF inoculation. The effects of drought and AMF were highly variable between species pairs. Overall, we found evidence of a three-way interaction between drought, mycorrhizae, and species pair on niche and fitness differences and the probability of coexistence. Most species pairs exhibited the highest probability of coexistence when both inoculated with AMF and exposed to drought conditions. The results of this study suggest that drought and AMF singularly and/or interactively influence the demographic parameters and interaction coefficients underlying plant community dynamics. Differences in coexistence probability between our treatments may implicate AMF as a key factor in whether species are able to coexist during projected increases in drought frequency. Thus, AMF could prove to be a potentially useful tool for managing plant community resilience to climate change. However, variable species responses to both drought and mycorrhizae suggest that under these conditions competitive outcomes might be affected by the strength of species-specific mycorrhizal mutualisms. Future studies on the interactive effects of mycorrhizae and droughts on plant competition should focus on identifying axes for plant species variation which may underlie the complex, species-specific interactions between mycorrhizal mutualisms and water availability.
Open Access
Navigating the Climate Crisis - The Interconnection of Extreme Weather Events and Life Decisions
(University of Oregon, 2024-05) Rosa-O'Hayer, Lyric
The climate crisis is no secret, and extreme weather events - a clear, visual manifestation of the climate crisis - are known to bring destruction in their wake. However, it is unclear how extensive of an impact they have on people. This research aims to answer the questions; how has the presence or experience of extreme weather events influenced college student's mental health and life decisions? Does this experience have a bigger impact than their knowledge of climate change? To answer this, a series of surveys (45 responses) and in-depth interviews (11) with environmental studies college students in Oregon was conducted, asking about their knowledge of climate change, experience with extreme weather events, feelings of climate anxiety, and how these impact their life decisions. Life decisions include but are not limited to whether to have kids, where to live, what to study, and career choice. Overall respondents expressed their belief in climate change and its impact on the severity of extreme weather events, and this knowledge impacted their politics, where to live, and what to study. This also led to the finding that experiencing exti·eme weather events can impact life decisions and mental health, but there are vaiying degrees of impact depending on the severity of the event, dictated by class status and knowledge of climate change. With this knowledge, there is the opportunity to advocate for better policies and initiatives ai·ound resources for post-exti·eme weather event care, as well as increased attention to preventative methods.
Open Access
Ethics in the Public Relations Professional World: A Guide For Those Entering the Field
(University of Oregon, 2024-05) Winz, April
This research project explores ethics in professional practice within the public relations and communications field, particularly in the context of higher education. Through qualitative one-on-one interviews, it investigates how practitioners navigate ethical considerations in their daily work and overall career. Findings reveal a gap between ethical parameters valued in the field and their practical implementation, highlighting a lack of training and support systems. As a result, participants have felt compelled to independently navigate ethical dilemmas throughout their career, and that college did not fully equip them with the tools they needed to do so. Drawing from these findings, the project proposes practical strategies such as mentorship, interactive and discussion-based workshops, and integration of diversity, equity, and inclusion (DEI) values to foster ethical decision-making in the field. The culmination of this research is encapsulated in a user-friendly guide tailored for college students, recent graduates, and new professionals entering the public relations and communications field. This guide offers actionable insights and advice drawn from real-world experiences, aiming to equip emerging professionals with the tools to find and uphold ethical standards throughout their careers.
Open Access
Assessing the Prevalence of Prescribed Fire in Pacific Northwest Wildfire Media Coverage
(University of Oregon, 2024) Wilson, Nathan
As climate change alters landscapes and exacerbates natural hazards like wildfires, people increasingly experience anxiety, dread, and loss, all of which negatively impact mental health. When the print media reports on wildfire events, previous research has shown that newspapers primarily focus on immediate developments, such as acres burned and containment efforts, rather than offering comprehensive discussion of wildfire, including strategies to mitigate future wildfire risk. Prescribed fire is one strategy to do so, and many ecosystems across the Pacific Northwest would readily benefit from more frequent, low-severity fire. This study seeks to determine whether print media in the Pacific Northwest follows a solutions journalism framework in their wildfire coverage, which, by highlighting solutions to prevalent problems, can provide readers with a greater sense of optimism and self-efficacy. Through content analysis, this study examines how often the Post Register, Idaho Spokesman, The Oregonian, The Register-Guard, The Seattle Times, and The Spokesman-Review mentioned prescribed fire in their coverage both during and outside of wildfire events, and the tone of that coverage, from 2010 to 2023. It found that major Pacific Northwest newspapers rarely mentioned prescribed fire when reporting on wildfires, but provided more coverage and more positive coverage of prescribed fire disconnected from specific wildfire events during the study period. These results show that large circulation print media outlets in the Pacific Northwest had positive coverage of prescribed fire overall, but relatively narrow coverage of wildfire events from a solutions journalism perspective.
Open Access
Litter decomposition in Oregon prairies depends on fire
(University of Oregon, 2024) Ralston, Ellen; Roy, Bitty
Prairies in the PNW were historically maintained by Indigenous burning practices, which favored some of their food plants and kept the prairies from becoming forested. Current prairie restoration practices are returning to the use of fire, but the consequences of fire for decomposition are unknown in these prairies. To examine decomposition, litter from both burned and unburned prairies was put in decomposition bags, and the bags were removed and weighed at three, six, and nine months. Half of all litter samples were also sterilized to remove their native fungal endophytes to determine whether that reduced decomposition. In general, litter from burned prairies had greater decomposition than litter from unburned prairies. Sterilized litter also had greater decomposition than unsterilized. This information can aid prairie managers as they continue to use fire to manage Oregon prairies.
Embargo
Seeds, Soil, and Shifting Climates: Climate Change's Impact on Food Security in the Willamette Valley
(University of Oregon, 2024) McCowan, Camille; Cutting-Jones, Hannah
Climate change poses a significant threat to global agricultural systems - raising global temperature, disrupting hydrological cycles, and impacting water patterns, soil health, and plant development. This threat is exemplified by the Willamette Valley, a region renowned for its agricultural diversity and fertile lands. This paper explores the relationship between global climate change, regional agricultural production, and local food security in the Willamette Valley. Through an analysis of the primary impacts of climate change on the agricultural sector, disruptions to ecological patterns, and potential secondary vulnerabilities, it seeks to understand the implications for local food production and security. Additionally, using the Willamette Valley as a model of an affected productive region, it examines the region’s current local food system and proposes strategies for local food production systems to mitigate the impacts of climate change.
Open Access
CULTIVATING CHANGE: ANALYZING THE GEOSPATIAL DYNAMICS OF URBAN AGRICULTURE AND THE CORRESPONDING DEIJ IMPLICATIONS IN PORTLAND, OREGON
(University of Oregon, 2024) Bowen, Karenna; Mhuireach, Gwynne
The discourse within the field of environmental science has been heavily dominated by discussions of mounting global crises stemming from growing urbanization. Downstream ramifications include food insecurity, the depletion of natural resources, and environmental concerns. As urbanization increases and access to rural land decreases, new solutions to ameliorate these issues become increasingly urgent. In response to these formidable concerns, urban agriculture (UA) is one potential solution that has grown in popularity. This thesis explores the premise of UA through a literature review that summarizes current research on the relevance, global trends, and its connection to the three pillars of sustainability—social, economic, and environmental. Building on this research, this study identifies a gap in knowledge associated with UA and diversity, equity, inclusion, and justice (DEIJ) implications. To address this, a case study is conducted in the neighborhoods of Portland, Oregon using ArcGIS Pro to assess UA’s impact on DEIJ from a racial, economic, accessibility, and environmental perspective. The results indicate that from a racial and ethnic standpoint, UA in Portland is located in primarily ethnically diverse neighborhoods. Relying on data exposing the median household income in Portland neighborhoods, UA is also determined through an economic outlook to be most prevalent in less affluent regions. To evaluate inclusion, it is found that UA plots are primarily accessible to the general public. Finally, from an environmental outlook, the distribution of UA is located typically in neighborhoods experiencing higher risk factors displayed by both the environmental hazard index and the urban heat island (UHI) index. Based on the findings from the literature review coupled with the data from the case study, it is concluded that Portland upholds many of the DEIJ principles through the implementation of UA. However, many of these issues have complexities that require future research regarding the long-term impacts between UA and DEIJ.
Open Access
Analyzing Lake Variability In A Highly Dynamic Area Of The Yukon Flats, Alaska Using Remote Sensing
(University of Oregon, 2024) Fleming, Catharine; Cooley, Sarah
Sentinel-2 optical imagery was used to track changes in lake area in a highly dynamic area of the Yukon Flats, Alaska over 2019-2023. Specific questions this research addresses include: how spatially consistent is the variability in water area? Why are certain lakes far less seasonally variable than others? How consistent is the temporal and spatial variability in the water area from year to year? Seasonal lake area fluctuations follow a similar progression from year to year. The seasonal maxima in lake extent are very pronounced for smaller water bodies in 2021 (20% higher average maximum lake area, 40% lower average minimum lake area) than larger water bodies. On average 2019 had the highest mean lateral change along lake shorelines while 2023 had the lowest.
Open Access
In the Neighborhood: Phenology, Species Interactions, and Community Engagement in Ecological Research
(University of Oregon, 2024) Callie, Bryn; Diez, Jeff
Phenology, the timing of biological life cycles, is a key indicator of global climatic change and a powerful tool for generating public awareness surrounding environmental issues. Multiple studies have shown that species are shifting their phenology in response to climate change, causing spring events such as leaf-out and flowering onset to arrive earlier and altering the way humans relate to the natural environment. Furthermore, although many studies have suggested that phenological differences influence the way that species within ecological communities interact, there has been minimal empirical consensus surrounding the impact of phenology on species interactions and even more limited research surrounding the reciprocal relationship — how species interactions impact phenology. This presents a significant knowledge gap as unprecedented rates of climate change and land-use change are altering plant community composition, diversity, and dynamics globally. As such, we studied the reciprocal relationship between flowering phenology, fitness, and competitive neighborhoods among annual plant species. We chose to utilize prairie species native to the Willamette Valley, reintroducing them to areas around the city of Eugene, OR and aiming to advance future restoration efforts by contributing to our understanding of their survival and persistence. Recognizing that public awareness and interest are key to the success of restoration and conservation initiatives, we embedded our experiments within urban natural areas and aimed to generate direct engagement with our research by encouraging community participation in phenological data collection. We found that increased competitor species richness was correlated with the advancement and shortening of flowering periods. We also found that plant fecundity was negatively correlated with competitor density but was unrelated to changes to competitor identity or species richness. Lastly, we observed that the strength of competition tended to vary by competitor identity, but that this variation did not seem to be related to the phenological differences present between species. Our research offers unique evidence that species interactions may impact plant phenology and fitness in complex ways and consequently species’ persistence and coexistence conditions in our changing global environment. Reflecting on the public engagement we witnessed, our project also demonstrates how ecological experiments can be used as an implement for both restoration and education.
Open Access
Exploring Barriers and Solutions to Active Travel to School: A Case Study of River Road/El Camino del Río Elementary Students in Eugene, OR
(University of Oregon, 2024) Staben, Alex; Brown, Anne
Active travel, or transportation modes requiring physical movement, builds physical activity into daily life, and for young children, much of their travel is to and from school. Active travel to school (ATS) improves physical, mental, and social health, as well as classroom behavior and attendance rates. However, since the 1970s, ATS has rapidly declined as more students ride to school in a vehicle. Transportation is inherently place-based; hence, this study focuses on Spanish-English dual immersion elementary school River Road/El Camino del Río (RRECDR) in the Eugene (OR) 4J school district. Like schools across the nation, very few RRECDR students use ATS. To understand why, I distributed a survey and completed follow-up interviews with parents of RRECDR students assessing 1) the barriers that factor into transportation choices and 2) what needs to change for ATS to increase among RRECDR students. Results indicate the need for a diverse multi-sector sustainable leadership team focused on ATS, increased ATS encouragement through group activities such as walking school buses (WSBs), and infrastructural improvements including crosswalk enhancements and advisory bike lanes in specific locations. Findings also suggest further research into the complex relationship between ATS and accessibility of heritage language immersion education and ATS (and active travel more generally) and the housing crisis.
Open Access
EARLY TRADE-OFFS OF ROOT TRAITS ON A MYCORRHIZAL COLLABORATION GRADIENT
(University of Oregon, 2023-06) Villano, Lindsay; Diez, Jeff
Aboveground plant traits exist on a spectrum defined by trade-offs between conservative and acquisitive resource uptake. However, belowground traits do not fit this axis because the uptake of soil nutrients can be outsourced to mycorrhizal mutualists. Thus, adding another axis in the root economic space that represents collaboration with arbuscular mycorrhizal (AM) fungi increases our understanding of fundamental variation in root traits. Mature roots exhibit trade-offs between investing in longer root structures that travel farther, or thicker roots that can better support mycorrhizae. Here, I explore whether young roots display trade-offs in collaboration intensity and if so, how long after germination species will begin to reflect niches on this axis. I hypothesize a negative correlation between root growth rate and colonization rate of AM fungi and that the relationship between these variables increases over time as plants refine their resource uptake strategy. I grew five native forb species for twenty-five days and sampled plants at eight time points after germination. Upon sampling, I recorded root length by analyzing the root's structure and then quantified percent colonization by AM fungi. I found that despite variation in species ' root length and colonization rates, they did not fo1m a negative relationship. The con elation of length and percent colonization did increase over time with intraspecific variation in the degree and direction of this correlation. The results of this study provide further insight on young root trait variation and benefit our understanding of species interactions in the rhizosphere that contribute to community dynamics.
Open Access
OUT ON A LIMB: DO HAZELNUT ORCHARDS PROVIDE HABITAT FOR CAVITY NESTING BIRDS?
(University of Oregon, 2023-06) Clayton, Adam; Hallet, Lauren
Cavity nesting birds are a group of high conseivation concern in the U.S. They depend on areas with mature decaying trees in which cavities can be excavated, but few studies have examined the role of managed landscapes such as orchards in providing nesting habitat. This study assesses the suitability of hazelnut orchards for cavity nesting bird species in the Willamette Valley, where hazelnut farming is a major industry. Using field sUIVeys, I measured the density of suitable tree cavities and size of tree limbs in four commercial hazelnut orchards, three experiencing heavy fungal decay, and one with limited decay. I used observations of birds in the same orchards to determine the abundance of all cavity nesting species. When comparing between orchards, cavity density increased with average tree diameter, but was much lower in the orchard with low levels of fungal decay. Black-capped chickadees were the most abundant cavity nesting birds observed, a smaller species dependent on nest sites with soft wood. These results suggest that orchards with mature trees experiencing fungal decay may be the most valuable for cavity nesting birds, but these qualities also make orchards vulnerable to diseases that reduce crop yield. To control key diseases, many older orchards are being replaced with new blight resistant trees, altering habitat connectivity for Willamette Valley birds. A regional management strategy where some mature, decaying orchard are instead retained could benefit declining bird populations.
Open Access
Impact of Rhizobia Presence and Nitrogen Abundance on Competition Between Legumes and Non-Legumes
(University of Oregon, 2023-06) Patel, Macy; Diez, Jeff
The mutualism between legume species and rhizobia has long been acknowledged as a vital part of plant community dynamics in both natural and agricultural systems. Increasing anthropogenic nitrogen inputs can alter this mutualism and in tum plant commm1ity dynamics. Still, few studies have explored the dependencies of these resource-based mutualistic microbes, rhizobia, on ambient nitrogen levels, and how this may affect competition between hosts and neighboring plants. To test the potential nitrogen-dependent role of rhizobia in mediating coexistence between legumes and non-legumes, we conducted a competition experiment in the greenhouse replicated across rhizobial inoculation and nitrogen fe1tilization treatments. Here, we employ contempora1y ecological theo1y to assess how rhizobia and nitrogen fertilization influence niche differences and fitness inequalities determining competitive outcomes. We measured the fecundity of plants across a competition gradient to parameterize annual plant population models and to use these parameter estimates to predict the outcomes of competition between our plant species. We found that both nitrogen and rhizobia shift the probability of coexistence, and further that the effect of rhizobia was dependent on nitrogen concentration. We also found that these results differed when legumes were competing with either other legumes or non-legumes. These results suggest that these context-dependent mutualisms are impo1tant in dete1mining competitive outcomes. Further, this study sheds light on the ways anthropogenic nitrogen inputs are likely to shift community composition and diversity of native plants and microbial communities alike.
Open Access
“Russian Heroes, French Zombies”: Diplomatic Tensions Between Great Powers in the Central African Republic
(University of Oregon, 2023-06) Wickstrand, Justin
This honors thesis examines the respective approaches of diplomatic engagement by Russia and France in the Central African Republic (CAR). Given the present competition between great powers on the African continent, much of the current discourse on this topic has a tendency to view this competition as a reemergence of the Cold War struggle over the “Third World,” specifically that which occurred in Africa. This thesis seeks to add to the present discourse by arguing that the notion of a Cold War redux in Africa is a reductionist approach that neglects the domestic priorities that are the veritable catalysts behind Russian and French engagement with Africa, specifically in the Central African Republic. The central aim of this project has been to analyze the motives and modes driving Russian and French engagement with the nation of the Central African Republic. By beginning with the historical background of France and the Soviet Union’s diplomatic engagement with Africa, I contextualize their patterns of diplomatic outreach and posit that the respective foreign policy legacies of the two powers contribute to their ability to act on the African continent today. Following this, I analyze the contemporary modes of engagement by France and Russia in the Central African Republic and evaluate the ways in which this has impacted their bilateral relationships with the CAR. By using a multimedia approach to primary source analysis in both English and French, I have been able to evaluate a wide-range of sources that contribute to the broader understanding of how diplomacy is being conducted on the African continent using the tools of the twenty-first century.
Open Access
How Festivals Influenced the Musical Landscape of the 1960s
(University of Oregon, 2023-05-16) Wilkinson, Olivia
This article uses a combination of sources, including music and its lyrics, works from other scholars, an interview with a Woodstock attendee, personal accounts, artwork, and video performances to gather a comprehensive view of each festival. The video footage consists of performances, outtakes of performances, and interviews, with more footage available with each subsequent festival. Song lyrics are used liberally as primary source material to track changes between festival eras. The Beatles are referenced periodically because their career trajectory was closely tied with popular music trends. Music, performance, and personal accounts are vital to understanding how the three festivals are connected and how festivals as a concept grow over time. The first chapter discusses the Newport Folk Festival and how the electric Dylan controversy sheds light on the festival as an event that showcased a bending of genres. Chapter two discusses the Monterey International Pop Festival and how the Bay Area where the festival took place is tied to the explosion of psychedelic drug use. The last chapter discusses Woodstock and why the war was important in understanding why the festival was more controversial than many remember today. Drugs, music, and freedom of expression colored the last years of the 1960s. A willingness to experiment was a strong characteristic of many of the youth of the decade, whether they became high-profile performers or stayed among the crowds, and was closely tied with the transitional periods discussed in this article.
Open Access
SHAPING OUR FATE: ANALYZING CIRCULAR ECONOMY PRINCIPLES IN CORPORATE SUSTAINABILITY STRATEGY AS A CRITICAL CLIMATE SOLUTION FOR THE APPAREL INDUSTRY
(University of Oregon, 2023) Stathis, Magdeline; Skov, Joshua; McWhorter, Brian
Apparel is one of the most polluting industries in the consumer goods sector. From microplastic pollution in waterways, to greenhouse gas emissions, and even the release of toxic chemicals into the habitats of biodiverse life, the production and consumption of garments is an extremely hazardous process in its current form. The circular economy is a transformational concept that reimagines how we consume clothing; it proposes alternative business models whereby companies can generate revenue without relying on the extraction of raw materials or the use of nonrenewable resources. However beneficial they may be, circular practices are contradictory to the way most apparel companies currently operate, making it a difficult scheme to implement. Not to mention, the textile value chain is a complexity in and of itself that challenges the prospect for change. This thesis will investigate the current efforts that resemble circularity strategy made by apparel companies and assess the current state of implementation of the economic model. Materials selection, resale, and recovery are highlighted as a few of several practices that exist in an entire toolkit for integrating circularity and addressing shortcomings of current linear business operations in apparel. Specifically, this study will examine the strategies mused to address material selection, resale, and recovery of goods by Patagonia, REI Co-Op, and Cotopaxi. In this piece, I suggest that circularity should be a common goal of all stakeholders in apparel to target the pollution caused by the industry globally. Though it remains unclear if 100% circularity is even possible to achieve – largely due to current consumption patterns and the complications of processing technical materials – it is still something that the industry should collectively work towards to reduce the environmental footprint of apparel.
Open Access
Invasive annuals increase with fire frequency in the Northern Great Basin
(University of Oregon, 2023) Bailey, Zoey; Hallett, Lauren; Aoyama, Lina; Moffitt, Michael
Wildfire, although a natural part of the sagebrush-steppe ecology in the Great Basin, is poised to occur at more frequent intervals due to the combined influence of rampant annual grass invasion and increasingly long dry seasons. Deviations from the historic fire return interval of 25-75 years to a mere 3-5-year cycle disrupt the establishment of later-seral species, such as the keystone shrub, sagebrush (Artemesia tridentata). More frequent fire can further alter the structure of plant communities by favoring early colonizing annual grass and forbs. As fire frequency increases, the resilience of native species is diminished, and the site becomes more vulnerable to vegetation compositional conversions. The conversion of mixed sagebrush and perennial grass-dominated sites to monocultures of invasive annual species jeopardizes human and wildlife needs on the landscape. To better understand the effects of increased fire frequency on annual species invasion, I surveyed vegetation cover in sites with variable burn history at the North Great Basin Experimental Range in July of 2022. The relative abundance of plant functional groups, as well as two critical invasive annual species, cheatgrass (Bromus tectorum) and desert alyssum (Alyssum desertorum), were recorded in plots burned in 5, 10, and 20 year intervals since 2002. The relationship between forb cover and fire frequency was the only statistically significant difference identified (p=0.02). General trends in the data supported the hypotheses that the mean percent cover of Bromus tectorum and Alyssum desertorum would be higher in sites burned more frequently. These preliminary findings indicate the relationship between fire frequency and invasive annual species warrants greater attention with future larger-scale vegetation surveys. A better understanding of fire frequency effects on vegetation conversion may help restoration practitioners effectively prioritize areas for post-fire restoration to limit loss of native species.
Open Access
Examining Variations in Fatty Acid Profiles of The Sea Star Pycnopodia Helianthoides On the Coast of British Columbia
(University of Oregon, 2022-11) Taradash, Aubrey; ; ;
Pycnopodia helianthoides is a large, predatory sea star native to the northeast Pacific coast. This important intertidal and subtidal predator was historically abundant along the west coast of North America from Alaska to Baja California until the 2013-2015 sea star wasting epidemic caused drastic population declines throughout its range. The opportunistic diet of Pycnopodia on benthic invertebrates has previously been studied through observation, but there are no published diet analyses using fatty acids (a trophic biomarker). In order to investigate the trophic ecology of wild Pycnopodia, fatty acids were extracted and identified from tissues of 119 individuals, ranging in size from 2.6-46 cm in diameter, collected from different sites and habitats near Calvert Island, BC, Canada. The multivariate fatty acid signatures of the stars were compared between collection sites and substrate types, as well as size classes (5 categories). Fatty acids were significantly different between sites and substrates, but not size classes. These differences suggest that the diets of stars found at different sites and substrates could differ significantly, although very few sites featured more than one substrate type, making it difficult to distinguish the potential effects of each. Size class, however, does not appear to have an effect on the fatty acid compositions of the stars, indicating that Pycnopodia diets may not vary much by size, which was unexpected. Further analysis of both wild and captive stars could continue to provide more insight into the diet of this understudied species.
Open Access
Amnesty’s Success in Transitional Justice and Human Rights; Spain, Chile, and South Africa as Case Studies
(University of Oregon, 2022-06) Feuerherdt, Lucy
This honors thesis examines the success of amnesty laws, relative to other mechanisms of transitional justice and redressing past human rights violations; it is my intention to understand if amnesty is a successful mechanism for countries transitioning to democracy after repressive periods. I demonstrate my research through a literature review of subjects and academic principles related to amnesty including concepts of justice, the human rights system, state- sanctioned violence, transitional justice, and amnesty laws. In addition to a review of the relevant literature, I utilize a case study analysis of three countries: Spain, Chile, and South Africa all used amnesty laws during their transitions to democracy in ways that are distinct from one another. These case studies provide a greater understanding of what makes an amnesty law successful and effective. The insight from the relevant literature along with the comparison and analysis from the case studies demonstrate that amnesty laws can be successful if implemented under a specific set of principles. I argue that the essential factors to an amnesty law’s success include the circumstances and state of the nation when amnesty is implemented, how additional transitional justice mechanisms are used, and if there are specific criteria within the amnesty law.

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