Digital Commons Network^™

Wilderness State Park Volunteers: A Qualitative Case Study Of Meaning And Sustainability, Christina A. Peterson

Master's Theses

In an increasingly urbanized world, parks, open space and wilderness areas are vitally important to human well-being. California State Parks provide people with the ability to connect with nature and engage in outdoor recreation. Moreover, these parks protect natural and cultural resources and preserve biodiversity. California State Parks are underfunded and rely on volunteers to support essential park services. The Wilderness State Park Uniformed Volunteer Program provides essential recreation, resource protection, and biodiversity services. In order to determine the elements of the volunteering experience that contribute to a strong sense of volunteer identity and meaning, a qualitative case study was …

Are Countries In Environmental Cooperation Concerned About Relative Gains?, Vivian Chinua Olivia Ike

Master's Theses

A country’s decision to join or withdraw from environmental cooperation has been argued by interest based theories to be influenced by the economic cost of international agreements, national interest of countries and the free-rider problem. However, this thesis argues that relative gains is a more decisive factor that influences the decision of countries in international arrangements. It hypothesizes that countries in environmental cooperation are concerned about relative gains. A content analysis of the statements of fifteen countries in international climate change cooperation are analyzed. The countries include the United States, Russian Federation, Canada, Japan, Australia, China, Brazil, South Africa, India, …

Reducing The Stem Gender Achievement Gap: Investigating Factors Influencing Female Students’ Major Choices, Shiyu Song

Master's Theses

Taking the first step to unveil female’s underrepresentation in STEM, this study adopts a mixed method design to explores possible factors that influence female college students’ choices to stay in or leave STEM. Undergraduates at University of Connecticut (N=386) completed an online questionnaire and female students who had either left (N=5) or were staying in STEM fields (N=7) were further selected to participate in the interview.

Results from the quantitative analysis showed that female students’ level of stigma consciousness is a significant predictor of their choice to stay in or leave STEM. Specifically, females who are more vulnerable to gender …

Mississippi College Towns: Assessing The Geography Of Collegiate Culture, Jordan Glynn Moore

Master's Theses

This study assesses the appearance of collegiate culture on the landscape of college towns in Mississippi. The research will add to the understanding of this phenomenon by contributing more focused studies of college towns not yet explored. Refining and adding to the concept of a “college town” by identifying physical and cultural factors that characterize it will open opportunities and provide options that will serve as a gateway for more pointed cross-disciplinary research. Not only are these towns havens for geographic research, but also for cross-disciplinary research pursuits due to their unique cultural characteristics. Using U.S. Census-derived maps and a …

The Impact Of Climate Change On Coastal Fog Hours Of California's Central Coast, Chrissy Rogers

Master's Theses

This study used observations and downscaled model output from the Coupled Model Intercomparison Project 5 to investigate diurnal temperature differences and their relationship to the number of fog hours in the future along California’s central coast. The study area extended north-south from Bodega Bay to the Santa Lucia Range and east-west from the coast of California to the western flank of the Sierra Nevada Mountains. Analyses of Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5 showed that most of California’s central coast will likely see minimal changes in the number of fog hours per day through the turn of the …

The Role Of The State, Multinational Oil Companies, International Law & The International Community: Intersection Of Human Rights & Environmental Degradation Climate Change In The 21st Century Caused By Traditional Extractive Practices, The Amazon Rainforest, Indigenous People And Universal Jurisdiction To Resolve The Accountability Issue, Marcela Cabrera Luna

Master's Theses

Local, national and international conventions that protect indigenous sovereignty and their territories, where many of the resources are extracted from by multinational corporations (MNCs) particularly oil, the number one commodity of the world and cause of climate change, continue to be jeopardized because of the lack of a clear international legal framework that can protect them and potentially hold multinationals accountable for their actions. These practices are causing not only environmental issues to the indigenous and surrounding communities, but climate change is in fact, the real human rights issue of the 21^st century and it affects everyone. By using …

Burrowing Owl (Athene Cunicularia) Diet And Abundance At A Stopover And Wintering Ground On Southeast Farallon Island, California, Sara Lee Chandler

Master's Theses

On the Farallon Islands the burrowing owl (Athene cunicularia) is a native migrant and predator of the non-native house mouse (Mus musculus) and the native ashy storm-petrel (Oceanodroma homochroa). Burrowing owl predation on the ashy storm-petrel is unnaturally exacerbated by the abundance of house mouse prey in the fall, which may encourage more owls to overwinter. When the cyclic mouse population crashes in winter, the owls prey upon storm-petrels, a species of conservation concern. In 2009, the U.S. Fish and Wildlife Service proposed eradication of the house mouse from the Farallon Islands in order to reduce owl predation on and …

Factors Affecting Western Snowy Plover Winter Foraging Habitat Selection In San Francisco Bay Ponds, Benjamin Gabriel Pearl

Master's Theses

Within the San Francisco Bay Area, Western Snowy Plovers (Alexandrinus

nivosus nivosus) nest and winter in former salt ponds. They face a number of threats

including human-altered habitats and high levels of predation by mesopredators and

raptors. The South Bay Salt Pond Restoration Project (the Project) is a large wetland

restoration project that will change and potentially eliminate snowy plover habitat in the

region. As the Project returns salt ponds to tidal wetland, there will be less of the dry,

flat, and sparsely vegetated habitat that plovers need for breeding and wintering habitat.

A greater understanding of the specific microhabitat …

Complex Effects Of Nitrogen Pollution And Grazing On Nectar Resources Of The Adult Bay Checkerspot Butterfly (Euphydryas Editha Bayensis), Nidhi Jain

Master's Theses

Recent anthropogenic increases in atmospheric nitrogen due to urbanization and combustion have had many adverse effects on natural systems, including loss of biodiversity, especially in sensitive habitats. One such region is the serpentine ecosystem of Coyote Ridge in San Jose, CA, the last refuge for recurring populations of the federally threatened Bay Checkerspot Butterfly (BCB) (Euphydryas editha bayensis). Increases in non-native grass cover and decreases in native forb cover (including cover of the BCB’s native larval host plants) have been attributed to the fertilizing effects of increased atmospheric nitrogen deposition. To counteract this effect, grazing has been implemented as a …

A Test Of Educational Methods To Reduce Boating Disturbance To Harbor Seals, Rachel Nicole Solvason

Master's Theses

Environmental education can affect attitudes and behaviors, but determining the most effective methods for protecting wildlife requires research. This study examined the effect of two modes of environmental education, one passive and one active, on the behaviors of boaters toward harbor seals (Phoca vitulina) at Corkscrew Slough in Redwood City, California, an area where harbor seals haul out and pup. Thirty-one boaters viewed an interpretive sign (passive environmental mode) and 30 experienced a docent talk (active) both designed to educate boaters on protecting harbor seals; 31 boaters received no environmental information (the control), therefore were not exposed to the interpretive …

Enzyme Level N And O Isotope Effects Of Assimilatory And Dissimilatory Nitrate Reduction, Lija Treibergs

Master's Theses

Nitrate N and O isotope distributions in the environment can be used to elucidate salient biogeochemical N transformations. In order to do so, it is necessary to know the isotopic imprints characteristic of respective N transformations, and to understand the underlying mechanisms that determine these patterns. In order to provide mechanistic constraints on the isotopic imprints associated with nitrate consuming processes, we measured the enzymatic N and O isotope effects (¹⁵ε and ¹⁸ε) imparted on nitrate by three types of nitrate reductase enzymes, including (a) a prokaryotic respiratory nitrate reductase, Nar, from the heterotrophic denitrifier Paracoccus …

Human Impacts On Rocky Intertidal Gastropods: Are Marine Protected Areas Effective?, Cassie Bednar

Master's Theses

As the human population has exponentially increased, so have anthropogenic effects on the ocean including pollution, eutrophication, acidification, changes in sea level, and overfishing. The California coast is visited by millions of people every year and is subject to a range of impacts. In the near-shore marine environment, people collect intertidal gastropods for food, bait or recreation. Collecting these animals has caused a decline in body size because humans preferentially take the largest individuals. Marine protected areas (MPAs), established to protect marine resources, may serve to reduce impacts to species, including gastropods. I collected 2510 individual samples to determine the …

Alfalfa Trap Cropping Increases Abundance Of Key Arachnids In An Organic Strawberry Agroecosystem, Sutapa Biswas

Master's Theses

Eighty three percent of the strawberries consumed in North America are grown in California, where the widespread use of insecticides has become hazardous to public health. The intensive use of pesticides for growing strawberries causes serious health risks to farm workers, in addition to contaminating the soil and groundwater. The cost to the environment and public health in the United States is estimated at $12 billion annually. Finding effective nontoxic management strategies for insect pests has become essential for long term sustainability. One strategy strawberry producers can use to promote sustainability is to increase the effectiveness of biological control techniques. …

The Relationship Between Motivation And Volunteer Satisfaction In Conservation Programs 2015., Raena Blumenthal

Master's Theses

Conservation leisure service organizations are relying more heavily on volunteers to sustain their services and protect natural resources (Strigas, 2006). However, research focusing on volunteer vacationers, those who spend money to volunteer, is still in its infancy. Drawing on functional theorizing (Bruyer & Rappe, 2007; Clary, Snyder, Ridge, Copeland, Stukas, Haugen, & Miene, 1998; Houle, Sagarin, & Kaplan, 2005; Katz, 1960; Smith, Bruner, & White, 1956), this study explored volunteer vacationers’ motivations and the relationships between motivations to volunteer, satisfaction with the volunteer vacation experience, and inclinations to volunteer in the future (in both local and nonlocal settings). The study …

A Pareto-Frontier Analysis Of Performance Trends For Small Regional Coverage Leo Constellation Systems, Christopher Alan Hinds

Master's Theses

As satellites become smaller, cheaper, and quicker to manufacture, constellation systems will be an increasingly attractive means of meeting mission objectives. Optimizing satellite constellation geometries is therefore a topic of considerable interest. As constellation systems become more achievable, providing coverage to specific regions of the Earth will become more common place. Small countries or companies that are currently unable to afford large and expensive constellation systems will now, or in the near future, be able to afford their own constellation systems to meet their individual requirements for small coverage regions.

The focus of this thesis was to optimize constellation geometries …

An Assessment Of Artificial Burrows For Burrowing Owls In Northern California, Sandra Menzel

Master's Theses

This study assesses artificial burrows as a management tool for burrowing owls (Athene cunicularia) at two study sites in northern California. The results of t-tests showed that artificial burrows that received annual surface maintenance (n = 113) at one site were occupied for a significantly (p ≤ 0.003) greater number of years than non-maintained (n = 51) artificial burrows at the other site. Maintained burrows were occupied for a mean of 1.90 years (SD = 2.04), compared to a mean of 0.45 years (SD = 0.97) for non-maintained burrows. Even with maintenance, occupancy rates dropped from 31% during the first …

Coast Redwood Community Structure And Composition Following Selective-Harvest: A Case Study Of Byrne-Milliron Forest, Amy K. Petersen

Master's Theses

The effects of selective-harvest on forest composition and structure in the southern range of the coast redwood (Sequoia sempervirens) forest have not been well documented. This case study was focused on the Byrne-Milliron Forest located in Santa Cruz County, where selective-harvest is currently the primary method of timber extraction. The purpose of this research was to determine how forest structure and composition changed in relation to time since the last harvest re-entry, the percentage cut per hectare and number of harvest re-entries. The study design consisted of 100 plots located within the Byrne-Milliron Forest, spanning over five harvest …

Using Vegetation To Reduce Nitrogen Runoff In California Caneberries, Rebecca Riesenfeld

Master's Theses

With a 700% rise in global fertilizer use in the last 50 years, agricultural lands are a significant source of nitrogen and phosphorus pollution in aquatic ecosystems worldwide. Record high levels of nitrate-contaminated runoff from agricultural sources in California's Central Coast are affecting drinking water supplies in the Pajaro Valley and increasingly threatening the ecological health of the Monterey Bay. Bands of vegetation strategically planted to control runoff and soil erosion, or vegetative filter strips (VFS), are used in urban landscapes and at some farm peripheries. On-farm vegetative diversity has been promoted for its contribution to biodiversity and pest control. …

A Promiscuous Wallflower: The Rare Zayante Sandhills Endemic Erysimum Teretifolium (Brassicaceae) Benefits From Outcrossing, Miranda Kathleen Melen

Master's Theses

The Zayante sandhills ecosystem of Santa Cruz County, California, contains a rich mosaic of plants and animals adapted to unusual soils and microclimates. In this environment, local adaptation of populations is expected to lead to greater endemism and outbreeding depression. Anthropogenic fragmentation has further isolated populations, however, which paradoxically could result in inbreeding depression. One of these plants, Erysimum teretifolium (Ben Lomond wallflower) is an endangered endemic herb in the Brassicaceae family. This study assessed genetic mixing across remnant patches of E. teretifolium in order to estimate the effects of fragmentation and the reliance on pollinators. A captive breeding colony …

Coast Redwood Fire History And Land Use In The Santa Cruz Mountains, California, Gregory Jones

Master's Theses

Physical evidence of past fires, left in the form of cambial scars, suggests that low and moderate intensity fires have burned periodically for centuries in the coast redwood (Sequoia sempervirens) forest in California's central coast bioregion. These fires may have played an important role in shaping stand age structure and composition. Nonetheless, the ecological role of fire in shaping successional processes in the redwood ecosystem is not well understood. The extent to which both aboriginal and more recent burning practices have affected the central coast landscape is also uncertain. Standard dendrochronology techniques were used to reconstruct and analyze …

Environmental Education As A Catalyst For Changing Students' Environmental Attitudes: A Survey Of Ten Universities In The Tokyo Bay And San Francisco Bay Areas, Minako Nishiyama

Master's Theses

Environmental education has been internationally recognized as a key tool to counter increasing threats to the environment. Previous studies have found that environmental values and beliefs are the fundamental factors that shape various pro-environmental behaviors. This study aimed to increase our understanding of how environmental education during childhood and university periods influence students' sense of connectedness to nature and ecological worldview. Two measures, the Connectedness to Nature Scale (CNS) and the New Ecological Paradigm (NEP) scale, were used for this purpose. A total of 1,266 students in 10 universities in the San Francisco Bay Area and Tokyo Bay Area participated …

An Analysis Of An Andean Cosmovisión: Nature, Culture, Ecology, And Cosmos, Christian Ardeleanu

Master's Theses

Modern life may offer certain benefits for humanity, but it can also create a barrier between humans and the natural world. In contrast, the millenarian Aymara culture of the Bolivian Andes exhibits a harmonic interrelation with nature, ecology, and the cosmos, and it also represents a living system of indigenous knowledge and knowledge production/transformation. The Aymara system of knowing and knowledge production, like other indigenous systems, should not be mistaken for antiquated elements of culture and folklore but should be seen as a distinct and dynamic epistemology. The Aymara cosmovisión is similar to the philosophy of ecology, sharing some general …

Characterization And Development Of An Extended Cavity Tunable Laser Diode, Fnu Traptilisa

Master's Theses

A laser diode emits a narrow range of frequencies. However, drifts in

frequency occur over time due to many factors like changes in laser temperature, current, mechanical vibrations in the apparatus, etc. These frequency drifts make the laser unsuitable for experiments that require high frequency stability. We have used an atomic transition in rubidium as a frequency reference and used Doppler

free saturated spectroscopy to observe the reference peak.

We have designed an electronic locking circuit that operates the diode laser at a specific frequency. It keeps the laser at that frequency for a long period of time with very …

Wastewater And Water Quality Changes In Lower South San Francisco Bay, 1957-2013., Simret Kesete Yigzaw

Master's Theses

The San José-Santa Clara Regional Wastewater Facility (Facility), located in the Lower South Bay (LSB), is the largest advanced wastewater treatment plant in San Francisco Bay. From 1957 to 2013, the Facility added a series of expansions and upgrades that increased treatment capacity and improved the quality of treated effluent.

This study addressed the questions: (1) To what extent have expansions and upgrades in the treatment plant during the past six decades resulted in improvements to Facility effluent quality? (2) How and to what extent have the changes in the Facility effluent translated into changes in the water quality of …

A Study Of The Collisional Evolution Of Orbital Debris In Geopotential Wells And Geo Disposal Orbits, Christina R. Diaz

Master's Theses

This thesis will present the effects of the orbital debris evolution in two key areas: the geosynchronous disposal orbit regime known as “graveyard” and the two geopotential wells found in 105◦ W and 75◦ E longitude bins. After developing a GEO specific orbit propagator for NASA Johnson Space Center’s Orbital Debris Of- fice, collisions were simulated throughout these regimes using a low velocity breakup model. This model considered the effects of perturbations particularly non-spherical Earth effects (specifically sectorial and zonal harmonics), lunar effects, third body effects and solar radiation pressure effects. The results show that CDPROP does well in simulating …

Ecotourism As A Tool For Conservation Of Coast Redwoods In Santa Cruz County, California, Chandana Rao

Master's Theses

According to the World Tourism Organization, ecotourism is the fastest growing segment of the tourism industry, generating $300 billion in annual revenue. Ecotourism aims to control the damaging effects of conventional mass tourism and tries to overcome tourism's environmental and socio-cultural challenges. In an ideal situation, ecotourism can help conserve fragile biodiversity, build ties between parks and communities, and increase awareness of environmental issues; it also includes a profit impetus for businesses.

This research was conducted to evaluate the potential for developing ecotourism as a conservation tool in the four redwoods state parks of Santa Cruz County. The study assessed …

Natural Recovery Of Second-Growth Coast Redwood Stands In The Santa Cruz Mountains, Jeffrey M. Sinclair

Master's Theses

The natural recovery of coast redwood forests following a logging event is not fully understood. Recent studies, in the redwood central range, have found that un-restored and unmanaged second-growth forest stands can begin to recover and exhibit characteristics of old-growth stands within 100 years or less. The goal of this study was to determine if redwood stands in their southern range are recovering naturally. A total of 160 sample plots were selected randomly within old-growth and second-growth study sites. The data collected included stand density, tree size structure, canopy cover, species diversity, and species composition. Special habitat features were analyzed …

Amphibian Mortality On Roads: A Case Study In Santa Cruz Long-Toed Salamander Habitat, Michael Thomas Hobbs

Master's Theses

Amphibian populations have been declining at higher rates than bird and mammal populations. Agriculture, urbanization, including roads, and resource extraction continue to put pressure on all species. Roads in particular, are major sources of mortality. The Santa Cruz long-toed salamander (Ambystoma macrodactylum croceum), one of the most critically endangered species in the US, is one amphibian that is declining as a result of anthropogenic impacts, especially habitat loss and fragmentation due to urban development. Migration across roads puts these salamanders at risk from road-related death. This thesis quantified the rate of road mortality to these salamanders and other common amphibians …

Benthic Invertebrate Response To Habitat Complexity In South Bay Salt Ponds, Jessica Louise Murphey

Master's Theses

Wetlands are unique ecosystems that support specific flora, fauna, hydrology, and geology. These ecosystems increase groundwater availability, improve water quality, decrease flood water impacts, and help decrease shoreline erosion. In the south San Francisco Bay, the South Bay Salt Pond Restoration Project is restoring over 6,000 hectares of former salt ponds to tidal marshes and managed pond habitats. These habitats will support endangered species as well as migratory birds, diving ducks, invertebrates, and algal species. Benthic invertebrates are a vital piece of the South Bay food web as they provide the sustenance for other invertebrates, fish, shorebirds, and waterfowl. Improving …

Basking Western Pond Turtle Response To Trail Use In Mountain View, California, Paul Eric Nyhof

Master's Theses

The western pond turtle (Emys marmorata) is the only native freshwater turtle in California, and it is listed as a California Species of Special Concern. One population near Moffett Naval Air Station in Northern California uses a highly altered water channel along a recently opened section of the Bay Trail, exposing western pond turtles (WPT) to high rates of human activity through recreational trail use. This research assessed whether human recreational trail use had a measurable effect on WPT basking behavior. WPTs were also trapped and marked to collect data on the structure and stability of the current population.

The …