Physical Sciences and Mathematics Commons^™

Building Detailed And Accurate Whole-Plant Concepts: A Morphometrics-Informed Reconstruction Of A Zosterophyll From The Lower Devonian Of Wyoming, Samar R. El-Abdallah

Cal Poly Humboldt theses and projects

The fragmentary state of plant fossils and the modular organization of plants make whole-plant reconstructions of fossil species desirable and feasible. Such reconstructions are key for integrating fossil species in systematic studies. The ca. 410 Ma Beartooth Butte Formation of Wyoming (USA) hosts the only rich Early Devonian plant assemblages in western North America, which fills a major gap in the phytogeography of this interval. I construct a whole-plant concept for a new zosterophyll from the Beartooth Butte Formation based on a detailed morphometric study. More than 600 fragments of the new zosterophyll were observed and 200 of those were …

Fire Severity Mediates Marten And Fisher Occurrence: Impacts Of The Dixie Fire On A Carnivore Community, Christopher James Collier

Cal Poly Humboldt theses and projects

The consumption of an astounding one million acres resulted from California’s largest single fire to date, the 2021 Dixie Fire. The social and economic losses associated with the fire were immediately apparent, but the effects on wildlife remained unknown. While previous research has suggested mixed or low severity fire may be beneficial to certain wildlife species, the responses to megafires are poorly understood for many carnivores. To better understand these responses to severe fire, I used a random sampling design stratified by burn severity to survey in and around the Dixie Fire footprint using baited camera stations. This allowed me …

Using Environmental Dna Methods For Estimating Juvenile Chinook Salmon Abundance, Jacqueline Marie Bridegum

Cal Poly Humboldt theses and projects

In the Central Valley of California, stocks of Chinook Salmon are declining, and two out of the four ecotypes of Chinook Salmon within the Sacramento River system are federally listed. A monitoring network has been developed to estimate the abundances of downstream migrating Chinook Salmon smolts, but there is high uncertainty in these estimates due to low catch rates. Environmental DNA (eDNA) monitoring, which involves capture of genetic material that organisms release into their surrounding environment, has shown promise for estimating abundance of salmonids and could complement existing monitoring efforts and potentially reduce uncertainty in abundance estimates. This research project …

Incorporating Equity Into Sea-Level Rise Planning: Perspectives From Practitioners Across California, Nayré Herrera

Cal Poly Humboldt theses and projects

Scholars along with national and state governments have increasingly made calls to incorporate an equity lens into climate adaptation processes and into sea-level rise planning specifically. However, the language used in these high-level policies remains vague. There remains a need to learn from practitioners on the ground about the challenges and opportunities for effectively incorporating an equity lens into sea-level rise adaptation and planning efforts. I conducted interviews with 17 individuals who are working within their agencies or organizations to advance equity across the California coast along with a review of 17 California coastal policy documents to gain insights into …

The "Upside-Down" River: Trends In Total Nitrogen, Total Phosphorus, And Microcystin Concentration In The Klamath Basin, 2010-2021, Kayla M. Fitzpatrick

Cal Poly Humboldt theses and projects

The Klamath River tends to experience impaired upstream water quality, which improves downstream. Although this consensus is accepted, an updated spatiotemporal analysis of certain water quality parameters has not been conducted since 2017. With four of the Klamath River’s dams slated for removal by the end of 2024, it is critical to have an updated assessment of current water quality conditions from which to compare conditions following dam removal. In this study, total nitrogen (TN), total phosphorus (TP), and microcystin data from 2010-2021 were analyzed to determine concentration trends from Link Dam to the Klamath River Estuary.

Concentrations of TN …

Basal Topography And Carbon Accumulation Rate Of A Rare Northern California Coastal Fen, Sarah Leidinger

Cal Poly Humboldt theses and projects

Increasingly, the importance of peatlands as biodiversity hotpots, year-round water storage features, and significant carbon sinks are being recognized. Despite this, they are one of the most vulnerable ecosystems globally. While some peatland conservation and restoration initiatives are being developed, a greater understanding of small peatlands is needed to make management decisions. This study aims to determine the timing of peat formation, peat volume, and carbon accumulation rates of the Conspicuous Scoop Fen, a small (2.1-acre) fen near Bridgeville, California (~840 m.a.s.l.). During the summers of 2022 and 2023, I collected 39 m of peat cores at 14 sampling locations. …

Habitat Selection And Habitat Use Of Gray Foxes (Urocyon Cinereoargenteus) On Trespass Cannabis Grows., Haley-Marie R. Jones

Cal Poly Humboldt theses and projects

Trespass cannabis grow sites, otherwise known as illegal cultivation sites on public lands, are extremely hazardous to the environment and can severely impact wildlife movement and behavior. Trespass grow sites are dangerous to wildlife as they negatively impact the quality of habitat and wildlife behavior through habitat modification, pesticide use, discarding of trash, and poaching on national forests. I researched gray fox habitat selection and habitat use at six different grow sites in the Klamath National Forest and Shasta-Trinity National Forest in northwestern California. I deployed GPS collars on three gray foxes at two of those grow sites and three …

Modeling Current And Future Saltmarsh Distribution In Arcata Marsh, Madeline Kay Mcnerthney

Cal Poly Humboldt theses and projects

Saltmarsh habitat is vulnerable to Sea Level Rise (SLR) and requires long-term management plans for communities to continue to benefit from their ecosystem services. This study analyzed the variation of above-ground vegetation biomass throughout I Street Marsh, using multiple variables, including classified vegetative community types, elevation and remote sensing indexes comprised of both visual (Red, Green, Blue) and non-visual (Red Edge, Near Infrared) bands. Plant community types were classified using a cluster analysis, and distinguished three communities, based on dominant species: Salicornia, Spartina, and a mixed type (diverse floristic makeup, with no dominant species). Above-ground biomass was significantly higher in …

A Picture Worth A Thousand Words: Factors Influencing Disability Accommodations, Alicia E. Martin

Cal Poly Humboldt theses and projects

Because not all disabilities look the same it is difficult to label a person with disabilities just by looking at them. Given that our knowledge, attitudes, and perceptions impact how we interpret our world and our willingness to act, people, including professors, may be biased toward providing accommodations for those with easily recognizable disabilities and biased against those with non-recognizable disabilities, and this may impact the disabled person’s ability to learn. This thesis aims to address whether professors’ disability-related attitudes, perceptions of accommodation reasonableness, and willingness to provide accommodations differ when the disability is recognizable (student is pictured in a …

Monitoring Bull Kelp (Nereocystis Leutkeana) Remotely At High Resolutions, Hannah E. Joss

Cal Poly Humboldt theses and projects

Bull kelp (Nereocystis leutkeana) is a foundational seaweed in nearshore, marine systems, traditionally supporting economically important fisheries, extracting nutrients in its vicinity, and sequestering carbon and transporting it great distances to subsidize shallow and deep-sea environments. Bull kelp is also a culturally important species for some indigenous peoples along the northeastern Pacific coastline and provides a harvestable product with growing demand. Global trends in kelp distribution show patterns of decline, and the immense loss of northern California bull kelp forests in response to climatic changes have highlighted the need for alternative sources of kelp, both for the product …

Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder

Cal Poly Humboldt theses and projects

Soil acidity is a common agricultural problem worldwide, as approximately 50% of all potentially arable soils are affected by pH limitations. At soil pH 3+) is considered to be the chemical form of aluminum in acid soil that hinders plant growth the most. Potentially, soil organic matter (SOM) can ameliorate the toxic effects of Al³⁺ on plants and microbes by binding with Al³⁺, thus preventing Al³⁺ (and other species of aluminum) from interacting in the rhizosphere. Increasing SOM also increases soil health indicators (i.e., microbial activity, soil water holding capacity, aggregate stability, porosity, etc.) while the …

Carnivore And Ungulate Occurrence In A Fire-Prone Region, Sara J. Moriarty-Graves

Cal Poly Humboldt theses and projects

Increasing fire size and severity in the western United States causes changes to ecosystems, species’ habitat use, and interspecific interactions. Wide-ranging carnivore and ungulate mammalian species and their interactions may be influenced by an increase in fire activity in northern California. Depending on the fire characteristics, ungulates may benefit from burned habitat due to an increase in forage availability, while carnivore species may be differentially impacted, but ultimately driven by bottom-up processes from a shift in prey availability. I used a three-step approach to estimate the single-species occupancy of four large mammal species: mountain lion (Puma concolor), coyote …

Hydrologic Outcomes For Ecological Meadow Restoration In The Northern Sierra Nevada, Emma Sevier

Cal Poly Humboldt theses and projects

Ecologically functioning meadows provide critical ecosystem services including improving a catchment’s water yield, flood dispersion and attenuation, fostering groundwater-dependent ecosystems, and creating natural fire breaks (Loheide and Booth 2011). Degradation from past and current land use has resulted in incised channels that change the magnitude and timing of watershed and meadow fluxes and cause water table decline. Process-based restoration (PBR) is an approach which leverages fluvial processes to increase restoration efficiency. Though PBR is a promising tool to restore degraded meadow ecosystems, more studies are needed to understand its hydrologic outcomes and whether hydrodynamic modeling can be used as a …

Macrolichen Inventory Of The Horse Mountain Botanical Area, Six Rivers National Forest, California, Usa, Sarah Norvell Conway

Cal Poly Humboldt theses and projects

Macrolichen diversity and community composition was determined for an area of high botanical interest in the Coast Ranges of Northern California – the Horse Mountain Botanical Area (HMBA) in Six Rivers National Forest. The Coast Ranges have been suggested to have high epiphytic macrolichen diversity, yet detailed site-specific macrolichen surveys are lacking for the area. Here we present comprehensive data on macrolichens of the HMBA integrated with environmental metadata at the landscape level. Twenty 0.4 ha sampling plots were positioned across the varying habitats of the HMBA and macrolichens were intensively sampled from all substrata. Out of 888 total collections, …

The Effects Of Post-Harvest Residue On Plantation Forest Soils And Early Growth Of Redwood And Douglas-Fir Seedlings In Humboldt County California, Robert W. Raibley

Cal Poly Humboldt theses and projects

Forest harvest residue (slash) usefulness has been up for debate among private timberland owners, public land managers, and the timber industry for decades. The disposal of slash, viewed as having low ecological value, has received considerable attention as wildfire risk has made burning it harder. In recent years, forest scientists and ecologists have recognized the importance of decaying wood and its relationship to forest growth and regeneration. At this site in Northern California, we looked at whether forest harvest residue enriches soil near slash windrows through soils coring and lab analyses, looking for primary limited nutrients nitrate (NO₃-N) …

Seasonal Growth, Movement, And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) Utilizing Restored Rearing Habitat, Monica S. Tonty

Cal Poly Humboldt theses and projects

The Scott River supports the most robust population of threatened Coho Salmon Oncorhynchus kisutch remaining in the Klamath River basin. Even in the Scott River, low quality and restricted extent of juvenile rearing habitat limits the Coho Salmon population to a small fraction of historic abundance. To support persistence and recovery of Scott River Coho Salmon, the Scott River Watershed Council (SRWC) has constructed a portfolio of restoration projects to improve juvenile rearing habitat, including beaver dam analogs (BDAs). The Scott River BDAs were the first implemented anywhere in California. This study compares juvenile Coho Salmon responses associated with production …

Food Waste Storage Gaseous Emissions Detection And Quantification Using Infrared Spectroscopy, Ryley A. Burton-Tauzer

Cal Poly Humboldt theses and projects

A growing interest in sustainable waste management and the implementation of new policies have prompted a shift towards alternative resource recovery methods for organic waste, including food waste. To effectively assess alternative food waste treatment scenarios, it is important to evaluate the life cycle impacts associated with each scenario. The storage phase of food waste, encompassing its accumulation in kitchens, and storage in bins for collection and transportation, has been overlooked as a source of greenhouse gases in previous studies. This investigation aimed to identify the greenhouse gases emitted during the initial five-day period of low-oxygen storage. An open dynamic …

Estimating Black Bear Population Parameters With Spatial Capture Recapture In A High Desert Mountain Ecosystem, Steffen D. Peterson

Cal Poly Humboldt theses and projects

Black bear (Ursus americanus) populations have grown and recolonized historic range in California, and unharvested populations are currently poorly monitored by existing programs. In the Warner Mountains of northeast California, increasing issuance of bear depredation permits has underscored the importance of black bear population monitoring. To study population density, space-use, and demographics of this unharvested population, I established 10 non-invasive sampling clusters, comprising a 3 x 3 arrangement of 4-km² grid-cells, across a 1,464 km² study area and monitored hair snares over five 10-day sampling occasions in summer 2018. Fourteen microsatellite and two sex-specific genetic markers …

Socio-Economic Comparative Analysis Of Front-Of-The-Meter And Behind-The-Meter Microgrids For Panamnik, Olivia C. Amann Mcshea

Cal Poly Humboldt theses and projects

In Northern California, the Karuk Tribe is feeling the effects of climate change on inadequate energy infrastructures leading to unreliable power supply. Improving energy reliability in a way that also increases energy sovereignty is necessary. Renewable energy microgrids have emerged as a pathway forward.

Modeling ownership structures and cash flows for different microgrid configurations can support the Tribe’s implementation of a microgrid in Orleans, CA that maximizes community benefits. This thesis considers a front-of-the-meter (FTM) and behind-the-meter (BTM) configuration, both approximately 2 MW solar PV and 3 MW/12 MWh battery energy storage. Cash flows including capital costs, operations and maintenance …

Perceptions Of Trail Safety In Humboldt County, California: An Analysis Of Safety Concerns, Factors That Impact Trail Use, And The Value People Place On Trails, Natalie C. Arroyo

Cal Poly Humboldt theses and projects

Trails in Humboldt County, California that are used for both transportation and recreation have myriad community benefits. However, people’s concerns about feeling safe can affect trail use, design, and development, as well as how trails are valued and perceived by residents. There has been a lack of information in Humboldt County about trail safety perceptions despite it being a factor that repeatedly arises in infrastructure planning and funding conversations. My research was focused on answering the following questions: (1) How do Humboldt County trail users perceive their safety on and near trails? (2) What factors affect these perceptions about safety, …

Comparative Analysis Of Gas Versus Electric Demand In Tiny House Communities For The Homeless, Christopher D. Beveridge

Cal Poly Humboldt theses and projects

Housing insecurity affects many communities. Because they can provide private and dignified spaces for living at low cost, tiny houses have become prominent in discussion about affordable housing. This project assesses whether electric or natural gas space heating provides the most cost-effective option for a tiny house in Arcata, California. Drawing from a comparative analysis between two tiny house communities for the homeless (THCHs), Home Yard Cottages in Spokane, Washington and Opportunity Village in Eugene, Oregon, this project offers recommendations for the eventual development of a THCH in Arcata. Comparison of energy bills from the THCHs with historical weather data …

Comparison Of Environmental Dna And Underwater Visual Count Surveys For Detecting Juvenile Coho Salmon (Oncorhynchus Kisutch) In Rivers, Jason T. Shaffer

Cal Poly Humboldt theses and projects

Environmental DNA (eDNA) has developed into a useful tool for determining the distribution of rare aquatic species, but relatively few studies have directly compared the detection probabilities of this method with other conventional survey techniques. These comparisons can inform which method may be better suited to address study objectives. In this study, the overall goal was to compare the ability of eDNA and underwater visual count (UVC) surveys to detect juvenile coho salmon (Oncorhynchus kisutch), a species of conservation concern at the southern extent of its geographic range. Specifically, I address two objectives: (1) compare the ability of …

Carnivore And Ungulate Responses To Cattle In A Grazed Forest Ecosystem, Rebecca Carniello

Cal Poly Humboldt theses and projects

Habitat disturbance, a leading threat to biological diversity, comes in many forms and can alter the behavior of wildlife and reduce the amount of suitable habitat. Livestock grazing, a form of habitat disturbance, is the most widespread influence on native ecosystems of western North America. Research on the impacts of introduced domestic herbivores on wild carnivores and ungulates varies, and the degree to which wildlife species are affected is often species-specific. I used remote trail cameras to compare the activity patterns of black bears (Ursus americanus), coyotes (Canis latrans), bobcats (Lynx rufus), mountain lions …

Techno-Economic Feasibility Of Electrifying Food Markets In Nigeria With Biogas Hybrid Mini-Grids, Demi Temitope Ogunwo

Cal Poly Humboldt theses and projects

This thesis explored the feasibility of electrifying a food market in an urban city in Nigeria with a hybrid biogas-powered mini-grid. Under the Energizing Economies Initiative of the Rural Electrification Agency of Nigeria, nine markets in the country currently receive constant access to electricity via hybrid mini-grid systems. As a majority of these systems are diesel-solar-battery systems, this thesis explored the use of biogas generators as a substitute for diesel generators in hybrid mini-grids for food markets. A fruit and vegetable market in Ketu, Lagos was used as a case study for the research. The research for this thesis was …

Estimating The Ecosystem Service Of Aleutian Cackling Goose Droppings On Pastures, Brian G. Fagundes

Cal Poly Humboldt theses and projects

The Aleutian cackling goose (Branta hutchinsii leucopareia) experienced a population low of 790 geese in 1974 and has recovered to the current estimate of 186,100 geese in 2021. Private livestock producers view geese as pasture competitors and use hazing and hunting to scare geese from private lands to adjacent public lands. I investigated if geese provide an ecosystem service via dropping fertilizing effects to improve pastures in northern California.

A greenhouse experiment was conducted from February-August 2019 at Cal Poly Humboldt, divided into two experiments: freshly sown ryegrass pasture and established plant and soil communities removed intact from …

Drought Responses Across Diverse Conifer Species, Habitats, And Competitive Gradients In Northern California, Gabriel J. Roletti

Cal Poly Humboldt theses and projects

Frequent and intense drought events are rapidly altering stand dynamics in western North American forests. Climate, competition, and site characteristics can affect the growth responses of individual trees to drought stress. The ecological and geographical diversity of northern California provides a unique opportunity to measure these responses across species, habitat types, and levels of competitive pressure. This study used dendrochronological techniques and linear mixed-effects models to assess growth responses to drought in four montane and two coastal conifer species across 54 study sites (nine sites per species and 540 trees total) in northern California. Growth was evaluated from 2002-2018 and …

Late Quaternary Glacier Fluctuations At Picayune Lake, Northern California, Aidan Patrick Cowan

Cal Poly Humboldt theses and projects

The Klamath Mountains are a 233-km-long (north to south) mountain range located in northern California that shows extensive geomorphic evidence of Pleistocene glaciation. Within the Klamath’s there are many highland lakes, which record evidence of glacial deposition, one of which is Picayune Lake. Lake sediment data collected from Picayune Lake offers insights into the glaciation, and broader depositional history of the Picayune Lake Valley, as well as the climate history of the Klamath Mountains region. I measured magnetic susceptibility, loss on ignition, and grain size in sediment cores and used radiocarbon dating to determine a chronology of glacier fluctuations in …

Examining The Impacts Of Beaver Dam Analogues And Groundwater Storage On Miners Creek, California, Miles Munding-Becker

Cal Poly Humboldt theses and projects

Beavers have been altering streams in North America for millions of years by impounding water behind their dams. The recent historical removal (intensely throughout the 18^th and 19^th century) of these dams altered the hydrology in low gradient streams from dynamic anastomosing streams and wet meadow complexes to incised channels with little structural diversity. Anthropogenic structures called Beaver Dam Analogues (BDAs) are used as a restorative process by mimicking natural beaver dams that can reverse channel incision, increase ponded and groundwater storage, and provide low velocity habitat for aquatic species and vegetation. A system of four original BDAs …

Protecting Public Trust Resources In America's Private Forests: Case Studies In The Diversity Of U.S. State-Level Forestry Policies, Brita Ann Goldstein

Cal Poly Humboldt theses and projects

Privately-owned forests in the U.S. provide ecological and socioeconomic benefits to Americans. At the same time, they challenge common law principles that govern the administration of public goods. There is long-standing tension between private property rights, which entitles forest landowners to make land management decisions about their properties, and the role of state governments in protecting public trust resources on behalf of the general public. Each state chooses to protect public trust resources on private lands in a different way, meaning the U.S. is a patchwork of diverse private forest policy approaches. Describing this range of approaches can help inform …

Assessing Soil Disturbance From Tethered Logging On Steep Slopes In Northern California, Karolyn Marie Fagundes

Cal Poly Humboldt theses and projects

The implementation of tethered harvesting allows for the expansion of mechanized logging onto steeper slopes. Recent updates to the California Forest Practice Rules have explicitly removed the slope limitation for logging equipment, provided it’s tethered. California is now witnessing the reintroduction of ground-based logging equipment on steep slopes. Previously, operating equipment on steep slopes was considered detrimental due to the potential for soil disturbance. However, tethered equipment interacts with the soil in a new way due to the use of a winch. Relatively few studies have attempted to quantify soil disturbance with this new practice. The goal of this study …