Digital Commons Network^™

The Ecological Impacts Of Un-Protecting Forests: The Case Of Gold Mining In Ghana, Tate Alexander Barend

Master's Theses

This paper estimates the causal effect of Ghana’s Legislative Instrument 2462 (L.I. 2462) on deforestation in protected areas. The policy redefined the regulatory regime governing small-scale gold mining in protected areas, moving from prohibition to discretionary permitting. I exploit the implementation of L.I. 2462 as a policy shock and apply a difference-in-differences event-study framework to a propensity score–matched sample of pixels derived from high-resolution satellite images. Contrary to widespread concerns that the policy would accelerate deforestation, the results provide no evidence of large-scale vegetation loss in exposed protected areas following the policy change. Instead, protected area pixels located within 5 …

Beyond Beliefs: Factors That Shape Agricultural Plastic End-Of-Life Management Among California Strawberry Growers, Kyle Y. Cahitas

Master's Theses

The practice of using plastics in agriculture is so prevalent it has earned its own name: plasticulture. One key plasticulture tool is polyethylene (PE) mulch film, a thin plastic sheet laid over the field for a single growing season and pulled out before the next. Because PE film is hard to recycle, most of it ends up in a landfill, yet how growers decide what happens to used plastic mulch has rarely been studied. To identify what shapes that decision, this study draws on a survey of California strawberry growers (n = 126). Twenty variables, spanning grower attitudes, farm characteristics, …

Biologically-Based Alternatives To Plastic Mulch Enrich Microbiome And Buffer Yield In Small-Scale Strawberry Production, Olivia L. Fragiacomo

Master's Theses

Much of commercial agriculture has used plastic mulch since the 1950s to contain fungicides and fertilizers, control weeds, retain soil moisture, and warm the top soil to start the growing season earlier. Research suggests that small-scale strawberry (Fragaria x ananassa) growers may be able to incorporate biological techniques, such as wheat straw mulch with microbial amendments, to reduce the use of single-use plastic mulch with a comparable yield. For this study, I carried out a randomized complete block comparison of five strawberry management techniques: plastic mulch (PM), straw mulch alone, and straw mulch inoculated with either arbuscular mycorrhizal fungi (AMF), …

A Socio-Ecological Study Of Coyote And Human Interactions In San Francisco Bay Open Space Preserves, Zhiyi Zhou

Master's Theses

Urban open space preserves support both intensive recreation and wildlife, but the information on carnivore activity and visitor perceptions is limited. This study combined camera-trap monitoring and on-site visitor surveys to evaluate activity patterns of medium- to large-bodied mammals and perceptions of coyotes at Windy Hill and Rancho San Antonio Open Space Preserves (South San Francisco Bay Area). From October 2024 to July 2025, thirteen cameras recorded 213,681 photo events; detections were standardized as detections per 1,000 camera-hours. Ten mammal species and two avian species were detected, including four focal carnivores: coyote (Canis latrans), bobcat (Lynx rufus), mountain lion (Puma …

Investigating The Structural Barriers And Opportunities For End-Of-Life Management Of Agricultural Plastic Waste Within California's Strawberry Industry, Rory M. O'Toole

Master's Theses

Agricultural plastic waste (APW) accounts for a significant and growing share of global plastic pollution, yet no study has documented how APW management functions across a specific crop system from production through end-of-life (EOL). This thesis addresses that gap by examining the structures and valuations that shape current EOL management of plastic mulch (PM) and drip tape (DT) in California's strawberry industry, one of the nation's most plastic-dependent crop systems. Drawing on an ethnographic approach that included 27 semi-structured interviews with stakeholders, as well as site visits, this study traces how APW is produced, valued, and discarded within a structurally …

Crop Yield Shocks And Conflict In Sub-Saharan Africa: Subnational Evidence From Satellite-Based Yield Predictions, Benson I. Adomako

Master's Theses

This paper examines whether crop yields affect violent conflict at the subnational level across seven Sub-Saharan African countries: Burkina Faso, Ethiopia, Mali, Malawi, Niger, Nigeria, and Tanzania, over the period 2010 to 2024. A central identification challenge is that observed yields are endogenous to conflict: armed violence disrupts planting, cultivation, and harvest. To address this, I train a machine learning model on observed maize yield and satellite and environmental features to generate predicted yields for 1,338 second-level administrative districts annually. These predictions serve as the key regressor in a two-way fixed-effects panel with district and year fixed effects. I find …

Programmable Degradation Of Polyethylene Via Amide-Functionalization: A Dual-Path Strategy Combining Palladium-Catalyzed Copolymerization And Enhanced Microbial Breakdown, Safi-Dapetel Balkissou Wouna

Master's Theses

Polyethylene (PE) is one of the most widely used polymers due to its durability, low cost, and chemical stability; however, these same properties contribute to its persistence in the environment. It takes about 1000 years for PE to be degraded by microbes in nature. This study investigates a molecular design strategy to enhance the biodegradability of PE by introducing polar functional groups into its backbone through palladium-catalyzed copolymerization with a Vince lactam-derived comonomer. This strategy was inspired by our previous observation that PHEVD (poly[7-(2-hydroxyethyl)-2,4-divinyl-3-oxa-7-azabicyclo[3.3.0]octane-6,8-dione]), a newly synthesized petroleum derived polymer that is rich of amide group, can be near-completely degraded …

Mobile Markets And Farmers’ Markets: Evaluating Food Accessibility For Underserved Communities In The Bay Area, Rajeshwari Rajesh

Master's Theses

Studies indicate including farmers’ markets, mobile markets, and other local food systems improve fresh food access for low-income communities, especially when paired with food assistance programs that offer financial incentives. This study aims to evaluate mobile markets and farmers’ markets in the Bay Area using the five dimensions of food access: accessibility, availability, acceptability, affordability, and accommodation. The study is based on primary data collected from 173 in-person surveys at six mobile and eight farmers’ markets in the Santa Clara and Contra Costa counties. Key survey participants were market shoppers participating in food assistance programs. A mixed research methodology included …

A Methodology To Reconstruct The Extent And Dynamics Of Historic Wildfires (1850-1950) In The Santa Cruz Mountains Of California, David Vásquez Ospina

Master's Theses

This thesis reconstructs the extent and dynamics of historic wildfires in the Santa Cruz Mountains of California between 1850 and 1950 using qualitative archival evidence from historical newspapers, maps, and related documents. A systematically coded database of 225 reports, consolidated into 155 unique wildfire events, was developed to analyze temporal and spatial patterns, ignition sources, vegetation types, suppression strategies, and impacts on communities and infrastructure. Historical rainfall records from the Boulder Creek station were integrated using water-year totals, three-year rolling averages, and standardized precipitation indices to examine how multi-year dryness relates to fire occurrence and size. Linear regressions show only …

A Triple Bottom Line Analysis Of Food Waste-To-Bioenergy At California University Campuses: Social Enablers Break Down Economic Barriers, Anjali Sharma

Master's Theses

Greenhouse gas emissions from food waste (FW) and energy generation are two major hurdles to the climate crisis. Previous research shows that waste-to-energy systems may provide a solution to both these challenges, particularly at university campuses, due to their high FW generation and high energy needs. Despite this, few academic institutions in California, US, have adopted waste-to-energy systems, and campus-specific challenges and opportunities associated with these systems remain underexplored. For this study, I use an Environmental, Economic, and Social (EES) lens to document the current landscape of FW management and implementation of food waste-to-bioenergy at campuses in each of the …

Alameda Song Sparrow Habitat Use Of Salt Pond Restoration Sites In South San Francisco Bay, Bradley A. Speno

Master's Theses

Restoration is acknowledged worldwide as a conservation need to return ecosystem functions. However, projects require monitoring to track system changes and assess restoration progress. In the San Francisco Bay, several large restoration projects are implementing plans to return salt-producing ponds to the historical ecosystem, tidal salt marsh. The Alameda song sparrow (Melospiza melodia pusillula), a California species of special concern, has been documented to use restored and historic marshes, but their use of restored salt ponds is not fully understood. The birds’ use of restored marshes may be a useful measure of restoration progress. This research investigated the relationships comparing …

California Utility-Scale Solar Energy Land Use Impacts On Species And Ecosystems, Ingrid Salazar

Master's Theses

Utility-scale solar energy (USSE), defined as projects of at least 1 megawatt, is rapidly expanding in California, which generated 37.5% of its electricity from renewables in 2023, with 24% coming from solar. While USSE supports decarbonization, it can also cause environmental harm, including biodiversity loss, habitat fragmentation, and land conversion. This study uses ArcGIS Pro 3.4.0 and public environmental data to analyze the spatial distribution of USSE projects, land use changes from 2013 to 2023, and occurrences of at-risk species across California’s bioregions. USSE development is heavily concentrated in the Mojave Desert, San Joaquin Valley, and Colorado Desert, which are …

Post-Fire Succession In An Old-Growth Coast Redwood (Sequoia Sempervirens) Forest In The Santa Cruz Mountain Bioregion, Mojgan Mahdizadeh

Master's Theses

Fire is a common disturbance in the western United States, and variation in its frequency and intensity can significantly impact species recovery and distribution across ecosystems. While fire frequency and intensity are increasing in coast redwood forests, little is known about how this forest type responds to high-intensity wildfires. In 2020, a high-intensity wildfire burned large portions of the coast redwood forest in the Santa Cruz Mountains, including over 1,700 ha of old-growth. This event created a unique opportunity to evaluate post-fire succession. This research assessed vegetation recovery across high and low to moderate severity burned areas using random sampling …

Sea Otter Behavior And Prey Composition Across Alternative Reef States In Monterey, Ca: Applying Ecological Theory To Kelp Restoration, Carter Hawkins

Master's Theses

Due to a myriad of factors, giant kelp (Macrocystis pyrifera) abundance along the California coast has decreased in select areas, leading to the formation of lower-diversity ecosystems dominated by purple sea urchins (Strongylocentrotus purpuratus), known as “urchin barrens.” While sea otters (Enhydra lutris) are keystone predators that help maintain kelp forests through predation on sea urchins, in Monterey, they avoid barren sea urchins due to their low energetic value and abundance of other habitat types, limiting their influence in these areas. From 2021-2023, sea urchin culling at Tankers Reef, a former barren site in Monterey Bay, was conducted to promote …

Experienced Latinx Urban Gardeners In San Jose, Ca, Offer Strategies For Climate Justice And Resilience, Claudia S. Damiani Fontana

Master's Theses

Low-income and underinvested communities will be disproportionately affected by climate change due to limited resources, inadequate infrastructure, and insufficient support systems. Urban gardeners are responding to the need to adapt to new climate conditions while sustaining their food sources and cultural practices. Many have adapted thanks to local interventions led by the government and non-profit agencies. For this study, I partnered with La Mesa Verde (LMV), a gardening and food justice program that works with low-income Latinx families in San José, and I documented the contributions of experienced Latinx gardeners, especially those with agricultural backgrounds, to climate-resilient gardening in San …

How Effective Are Engineered And Non-Engineered Riparian Forest Restoration Projects In Providing Salmonid-Quality Habitat In The San Francisco Bay Area?, Alexander Ivanov

Master's Theses

Streams and their riparian zones in the San Francisco Bay Area have been degraded, severely harming salmonid populations in the region. Ecological restoration is a common approach to return stream function. Such restoration projects vary widely in intensity, from low-impact vegetation removal/planting to highly engineered projects involving structures and grading. This research investigated the effectiveness of streams restored using engineered versus non-engineered solutions in supporting salmonid habitat viability in San Francisco Bay Area streams. Fourteen streams, seven from each of the two types of restoration, were sampled in the wet and dry season in 2024, three times each season. Data …

Sustainability In Professional Sports: A New Nexus Of Profit And Social Responsibility, Matthew Teplitz

Master's Theses

The world is facing a climate crisis – corrective action that will improve our collective situation is needed, now. Those with the power to do so, in the capitalist structure under which we live, are largely the individuals, corporations, and governments with financial resources and the platform to inspire others to act. Two such entities, complete with the financial heft to make a difference and inspiration to spare, are North America’s National Basketball Association (NBA) and Spain’s La Liga. This thesis seeks to understand what distinguishes the NBA’s approach to sustainability from La Liga, and by employing each league as …

The Impacts Of Recreational Infrastructure On Mammal Use Of Riparian Zones In Northern California Regional Parks, Emily A. Matthews

Master's Theses

Public lands have been important for the protection of riparian habitats; however, many public lands are also used for recreation, which can reduce mammal habitat use. Understanding how mammals are affected by recreation in riparian areas can help guide management decisions. The goal of this research is to understand the effect of recreation on mammal use of riparian habitats in two popular East Bay Regional Parks, Charles Lee Tilden and Wildcat Canyon, and to map the extent of that impact. Cameras were deployed in the riparian areas of a high, moderate, and low development site (Alvarado, Tilden, and Wildcat Canyon) …

Using Moss As An Inexpensive Air Pollution Bioindicator For Environmental Equity In Santa Clara Country, California, Tam Dan Tran

Master's Theses

Toxins pervade urban areas and pose long-term health risks to humans. I examine moss as an affordable bioindicator and assess whether moss monitor results reflect other air quality (AQ) indicators, environmental factors, and social vulnerability. Specifically, I investigate (1) whether moss is an effective atmospheric pollution indicator and (2) whether low-income or high-lead-risk neighborhoods experience greater exposure to air pollution. I set out Hypnum cupressiforme moss for two months of exposure in 28 Santa Clara County locations and then measured chromium, zinc, nickel, and the loss of chlorophyll fluorescence in the moss tissue. I gathered real-time particulate matter (PM2.5) measurements …

An Assessment Of Anthropogenic Injuries On White Sharks (Carcharodon Carcharias) In Central California, Kaitlyn Yee

Master's Theses

As human activities increasingly impact marine ecosystems, understanding the effects of anthropogenic activity on white sharks is important for their continued conservation. Human-induced injuries are observed in many shark species. Such injuries have been found to have physiological and ecological impacts. Four sites in Central California off the coasts of Aptos, Año Nuevo Island, Southeast Farallon Island, and Point Reyes are all known areas of white shark aggregation with varying levels of human use and protection. Utilizing a vast video database, this study evaluated the effects of natural and non-natural anthropogenic shark injury types across all locations, age classes, and …

Exploring Community Adaptation To Public Safety Power Shutoff Events: Findings From Two Case Studies Of Unincorporated Mountain Communities In Southern California, Ramiro M. Brown

Master's Theses

As aging electrical infrastructure in the US continues to succumb to unyielding weather patterns brought on by climate change, there is an urgency among Investor-Owned Utilities (IOUs) to reduce the likelihood of their equipment sparking a wildfire. Public Safety Power Shutoffs (PSPS) – the intentional de-energization of the electrical grid on high fire weather danger days – have become a staple in IOU Wildfire Mitigation Plans (WMPs) since 2018 as one way to avoid wildfire ignitions via electrical infrastructure. One criticism of PSPS events is that they create their own hazard by cutting off power to thousands – sometimes millions-of …

Mammal Response To Wildfire In Redwood Forests In Northern California, Kristine Doerr

Master's Theses

California has historically experienced recurrent wildfires that have shaped many of the region’s unique ecosystems such as coast redwood (Sequoia sempervirens) forests. Redwood forests, particularly old-growth redwoods, are vital habitats for many wildlife species. Still, these long-living, fire-resistant trees are facing altered fire regimes due to fire suppression and climate change. The 2020 CZU Lightning Complex Fire was a consequence of these changes and significantly altered the landscape of the Santa Cruz Mountain region. This study analyzes mammal recovery after wildfire in high and low fire severity locations of the CZU Fire using two camera trap grids. The high-severity grid …

Win-Win Ecology: Can Mosses Promote Dudleya Germination To Restore California Quarries?, Kate L. Worrell

Master's Theses

Human actions directly damage habitat for native plants; restoration ecology facilitates successful plant re-establishment in these environments. Open-pit mines leave behind steep, rocky, and nutrient-deficient habitats that are some of the most degraded ecosystems on the planet. Dudleya or ‘live-forevers’— a genus of native California succulent plants that contains many rare, threatened, or endangered species — grow on rocky cliffs and may create a successful reclamation-restoration story. However, Dudleya germination is poorly understood. Much of the literature on Dudleya cites a single field report suggesting that bryophytes facilitate germination, but no previous experiments have evaluated this proposal. In this study, …

A Trailside Study Of A Coast Redwood Forest Understory Specis, Trillium Ovatum, In The Santa Cruz Mountains, Mary Yan

Master's Theses

To fully understand one of the world’s greatest terrestrial carbon sinks, the coast redwood forest, a co-occurring species may be the key to unique and accessible opportunities to collectively monitor the health of this important habitat. I investigated the relationship between hiking trails and Trillium ovatum within the redwood forests of three California State Parks. Utilizing quadrats across 115 one-meter plots and 58 10-meter transects, T. ovatum occurrence and abundance were recorded and analyzed with factors including proximity to trails, distance from streams, elevation, slope, canopy cover, duff depth, co-occurring understory species, and tree species dominance. Results indicated a higher …

Barriers To And Solutions For Fuel Treatments In The Central California Coast Ranges, Sierra Dawn Lyman

Master's Theses

In recent years, the Western United States has experienced an increase in fire activity due to multiple factors, including anthropogenic climate change, historical forest management focused on suppression, and the expanding wildland urban interface (WUI). In response, California is working to accelerate the pace and scale of forest management and fire hazard reduction efforts. Although fuel treatment projects are being implemented, they often encounter various barriers. While existing literature highlights these barriers, it tends to overlook the solutions being applied in practice to overcome them. Using an ethnographic approach that includes key informant interviews and participant observation in four sites …

Comparing Shade And Impervious Surface Area With Extreme Heat And Environmental Equity: An Analysis Of The Urban Heat Island Effect In Santa Clara County, California, Jamsheed R. Mistry

Master's Theses

In the modern epoch of the Anthropocene, the rapid rise in urban sprawling has prompted a disproportionate exposure to extreme heat within underserved communities. As the global populace becomes increasingly urbanized, the inevitable formation of urban heat islands is becoming an imminent cause of concern for environmental and social justice. Due to an increase in urbanization, anthropogenic activities have not only increased the energy demand for cooling initiatives but also have increased the intensity of heat-related illnesses, such as heart attacks, dehydration, and respiratory diseases. Additionally, urbanization has yielded an unequal distribution of heat exposure and heat-related illnesses, particularly in …

Evaluating Climate Migration Through Discourse Analysis Of International Policy Framework And “El Progreso” Community Blog, Olusola Akanni

Master's Theses

ABSTRACT

Environmental changes are driven by global warming, such as rising temperatures, melting ice, and increased natural disasters which directly affect the living conditions of huma thereby driving migration. This study highlights the inadequacies of current migration management policies as the United States is seeing a significant influx of migrants from Central America. The focus of this discourse analysis is on the role of inadequate policies and the failure of international efforts like the Paris Climate Agreement in addressing the issue of climate-induced migration effectively. Despite the goals set by such international agreements to mitigate the effects of climate change …

Impact Of Temperature On Children’S Nutrition: A Comparative Study Of Three Ecological Regions Of Nepal, Prakriti Shakya

Master's Theses

Nutrition obtained during the growth period of childhood significantly influences long-term well-being and overall productivity, ultimately contributing to the economy of a society. However, weather shocks can wreak havoc by damaging crops, changing yields of important crops and disrupting market access, which directly impacts the food intake of both adults and children. When these adverse events occur during childhood, short term and long term inadequacy in nutrition as well as disease incidence can cause malnutrition leading to stunted growth and cognitive impairment that may persist into adulthood, affecting the labor market and increasing health expenditure. To address this issue, we …

To Burn Or Not To Burn: Causal Effect Of Farm Stubble Burning On Air Quality., Chaitanya Pasupala

Master's Theses

National Capital Region of India (NCR) experiences adverse air quality during winters with Air Quality Index (AQI) at hazardous levels. Though various factors like industrial and automobile emissions, biomass burning, and firecrackers during festive season contribute to NCR’s adverse air quality, farm stubble burning in neighbouring agricultural regions of Punjab and Haryana is considered a prominent one. The motivation and consequences of farm-stubble burning in Punjab and Haryana have been extensively studied but the causal effect of this burning on air quality of Delhi has neither been rigorously analyzed nor the effects quantified. This study aims to bridge this gap …

Habitat Characterization Of American Badgers (Taxidea Taxus) Of Northern California, Mitchell Victoria

Master's Theses

American badgers (Taxidea taxus) are a semi fossorial mammal that lives in grassland and open prairie ecosystems as well as coastal prairies, agricultural fields, deserts, and deforested habitats. Many researchers have published work on badgers, but we still require more information on their ecology. The American badger is a semi fossorial, solitary, predatory mammal of grassland ecosystems. They are classified as mesopredators when compared to larger apex predators such as brown bears, wolves, and pumas. However, when larger carnivores are absent, Badgers become apex predators of their ecosystems. Los Vaqueros Watershed in Brentwood, California, was my study site because badgers …