Physical Sciences and Mathematics Commons^™

The Tidal Prism, Viable Eelgrass Habitat, And The Effects Of Sea Level Rise In Morro Bay, Kaden A. Caliendo

Master's Theses

The tidal prism, or the volume of water exchanged from the sea to an estuary from mean low to mean high tide, influences system hydrodynamics and ecological functioning. Since 1884, the tidal prism in Morro Bay, California has been estimated to be decreasing over time due to sedimentation from upstream practices. What is the current tidal prism in Morro Bay and how will that change with sea level rise? How will eelgrass respond to rising sea levels?

For this study, inexpensive tidal gauges were deployed at four locations in Morro Bay from March to August 2023 to measure spatially varying …

Hydrologic Response Of Little Creek To The 2020 Czu Lightning Complex Fire At The Swanton Pacific Ranch, Kylie E. Dupuis

Master's Theses

In this study, stage, streamflow, and precipitation data was collected from small watersheds in the Swanton Pacific Ranch for the first two hydrologic years following the 2020 CZU Lightning Complex. The Little Creek watershed was setup for high-resolution data collection with four separate stage gauge sites (Main Stem, North Fork, South Fork, and Upper North Fork) and four rain gauge sites (Al Smith House, Ridgeline, Upper North Fork, and Landing 23). Stage gauge sites were also established at Queseria, Archibald, and Mill creeks. Preliminary post-fire rating curves were developed for the four sites of Little Creek. The Main Stem (MS) …

Soarnet, Deep Learning Thermal Detection For Free Flight, Jake T. Tallman

Master's Theses

Thermals are regions of rising hot air formed on the ground through the warming of the surface by the sun. Thermals are commonly used by birds and glider pilots to extend flight duration, increase cross-country distance, and conserve energy. This kind of powerless flight using natural sources of lift is called soaring. Once a thermal is encountered, the pilot flies in circles to keep within the thermal, so gaining altitude before flying off to the next thermal and towards the destination. A single thermal can net a pilot thousands of feet of elevation gain, however estimating thermal locations is not …

Characteristics And Management Implications Of Mollic Soils In Forest Versus Grassland Settings In Central California, Brian Charles Clark

Master's Theses

Efforts to sequester soil carbon (C) should consider soils intrinsically capable at C retention. Of the mineral soil orders, Mollisols have minimum requirements for soil organic C (SOC; over 0.06 %) and basic saturation (over 50 %). In the U.S., grasslands comprise 93% of the vegetation mapped above Mollisols. Soils beneath the southern extent of Sequoia sempervirens (redwood) forests in central California are mapped as Molliols. It widely accepted that redwood forests harbor considerable biomass C, but the extent to which aboveground C is retained in the soil is not well understood. This study aimed to: (i) to gather baseline …

Eelgrass (Zostera Marina) Population Decline In Morro Bay, Ca: A Meta-Analysis Of Herbicide Application In San Luis Obispo County And Morro Bay Watershed, Tyler King Sinnott

Master's Theses

The endemic eelgrass (Zostera marina) community of Morro Bay Estuary, located on the central coast of California, has experienced an estimated decline of 95% in occupied area (reduction of 344 acres to 20 acres) from 2008 to 2017 for reasons that are not yet definitively clear. One possible driver of degradation that has yet to be investigated is the role of herbicides from agricultural fields in the watershed that feeds into the estuary. Thus, the primary research goal of this project was to better understand temporal and spatial trends of herbicide use within the context of San Luis …

Incorporating Shear Resistance Into Debris Flow Triggering Model Statistics, Noah J. Lyman

Master's Theses

Several regions of the Western United States utilize statistical binary classification models to predict and manage debris flow initiation probability after wildfires. As the occurrence of wildfires and large intensity rainfall events increase, so has the frequency in which development occurs in the steep and mountainous terrain where these events arise. This resulting intersection brings with it an increasing need to derive improved results from existing models, or develop new models, to reduce the economic and human impacts that debris flows may bring. Any development or change to these models could also theoretically increase the ease of collection, processing, and …

The Strawberry Rhizosphere Microbiome: Role On Plant Health And Nutrition, Eric Michael Boyd

Master's Theses

Microbial-root associations are important to help plants cope with abiotic and biotic stressors. Managing these interactions offers an opportunity for improving the efficiency and sustainability of agricultural production. By characterizing the bacterial and archaeal community (via 16S rRNA sequencing) associated with the bulk and rhizosphere soil of sixteen strawberry cultivars in two controlled field studies, we explored the relationships between the soil microbiome and plant resistance to two soilborne fungal pathogens of strawberry (Verticillium dahliae and Macrophomina phaseolina). Overall, the plants had a distinctive rhizosphere microbiome relative to the bulk soil, with higher abundances of known beneficial bacteria …

Estimating Evapotranspiration Of A Riparian Forest Using Sap Flow Measurements, James R. Solum

Master's Theses

To close the water use budget of irrigated agricultural fields in floodplains with substantial riparian corridors, it is necessary to understand groundwater usage by dominant phreatophytic vegetation, particularly when the primary source of water for irrigation comes from groundwater abstraction. We report here results of estimated evapotranspiration (ET) of a riparian forest, which were based on measurements of sap flow in phreatophytic vegetation within a riparian corridor. The riparian corridor was within a study area 75 to 140 meters wide in the lower portion of the Scotts Creek watershed, which is bounded to the west by the Pacific Ocean in …

Host Plant Resistance In Strawberries To Anthracnose And Colonization Of Crown And Root Tissue By Verticillium Dahliae And Macrophomina Phaseolina, Omar A. Gonzalez-Benitez

Master's Theses

Strawberries are considered an important crop in California where in 2018 it was in the top 5 valued fruit and vegetable commodities valued at $2.84 billion accounting for 88% of the total U.S. production. Strawberry production can be severely impacted by soilborne pathogens that can affect strawberry roots, crowns and leaves which can result in plant mortality. As much as 50 to 60% mortality can occur in one field. Pathogens responsible for such losses include Colletotrichum acutatum (syn.C. nymphaeae), Macrophomina phaseolina and Verticillium dahliae. With the phaseout of methyl bromide, host resistance and an understanding of host-pathogen interactions …

Effectiveness Of Windrow Composting Methodology In Killing A Thermo-Tolerant Species Of Salmonella During Mortality Composting, Spencer Gabriel Myers

Master's Theses

In a large agricultural operation, such as the one at Cal Poly San Luis Obispo, disposal of deceased animals is an immense issue. The cost of transporting and rendering every dead animal is inhibitory to the general function of the agricultural operations and their thin budget. Therefore, we propose that composting mortalities could be an economical alternative. Composting is a recognized method for taking animal waste products along with carbon waste and turning it into a pathogen-free, nutrient-rich topsoil. Carcass composting is in fact performed in other countries and states to varying degrees of success. However, the California EPA limits …

Quantifying The Environmental Performance Of A Stream Habitat Improvement Project, Cody Morse

Master's Theses

River restoration projects are being installed worldwide to rehabilitate degraded river habitat. Many of these projects focus on stream habitat improvement (SHI), and an estimated 60%of the 37,000 projects listed in the National River Restoration Science Synthesis Program focus on SHI for salmon and trout species. These projects frequently lack a sufficient monitoring program or account for the environmental costs associated with SHI. The present study used life cycle assessment (LCA) techniques and topographic effectiveness monitoring to quantify environmental costs on the basis of geomorphic change. This methodology was a novel approach to assessing the cost-benefit relationship of SHI. To …

Field Investigation Of Stream-Aquifer Interactions: A Case Study In Coastal California, Devin Pritchard-Peterson

Master's Theses

This study is a detailed investigation of the dynamic interaction between a stream and an alluvial aquifer at Swanton Pacific Ranch in the Scotts Creek watershed in Santa Cruz County, California. The aquifer is an important source of groundwater for cropland irrigation and for aquatic ecosystem support. The potential for groundwater pumping to deplete Scotts Creek stream flows is a source of serious concern for land managers, fisheries biologists, and regulatory agencies due to the presence of federally protected steelhead trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch). An understanding of the interaction between the stream and pumped aquifer will …

Hydrologic Response To Conifer Removal From An Encroached Mountain Meadow, Gregory F. Van Oosbree

Master's Theses

Meadows in the Sierra Nevada Mountains are an important ecological resource that have degraded in quality and distribution due to several environmental and anthropogenic stressors. The encroachment of conifers beyond forest meadow ecotones is largely responsible for the decline of meadow habitat throughout the past century. Currently, there is little research that quantifies the hydrologic response to removal of conifers encroaching meadows in terms of implicating successful meadow restoration. This study has implemented a before after control intervention (BACI) study design to determine the hydrologic response associated with the removal of conifers from a historic meadow encroached by conifers. The …

Using The Papathoma Tsunami Vulnerability Assessment Model To Forcast Probable Impacts, And Planning Implications, Of A 500-Year Tsunami In Cayucos, California, Andrew Robert Marshall

Master's Theses

This report focuses on using the Papathoma Tsunami Vulnerability Assessment Model (PTVA) to demonstrate the vulnerability of Cayucos to a 500-year tsunami, and using the results to inform specific planning recommendations. By modeling inundation with GIS and analyzing building attributes via the PTVA model, this study has gone beyond any previous vulnerability assessments of Cayucos. Findings include: delineation of the most vulnerable areas, estimates of numbers of lost civic buildings, commercial buildings and houses, as well as estimates of people displaced from tsunami damaged homes. The report goes on to discuss what mitigation measures are in place and what further …

Comparative Analysis Of Two Successive Vintages Of Cabernet Sauvignon Must And Pre-Barrel Wine From Two Distinct Soil Types, Jon Garret Page

Master's Theses

The objective of this study was to determine if there were significant statistical differences in the response variables of Cabernet Sauvignon must and pre-barreled wine analyzed from two vintages from two distinct soil types.

Research was conducted at California Polytechnic University, San Luis Obispo to examine the quantitative chemical analysis of 22 different response variables of Cabernet Sauvignon grapes. The same 22 variables were analyzed in must and pre-barreled wine samples harvested from both Calodo Clay Loam soil and Zaca Clay soil. The analyses were done at both California Polytechnic University, San Luis Obispo and Vinquiry Inc. Labs. The results …

The Influence Of Hydrogeomorphology, Soil Redox Conditions, And Salinity On The Spatial Zoning Of Saltgrass, Salt Rush, And Cattails In Scotts Creek Marsh, Swanton Pacific Ranch, Ca, Mark D. Gormley

Master's Theses

Scotts Creek Marsh (SCM) is a small coastal wetland ecosystem in Davenport, CA. The vegetation of SCM is dominated by three halophytic zones comprised of saltgrass, salt rush, cattails. The objectives of the study were (i) to investigate the variables that influence the zoning of the three dominant halophyte communities in SCM and (ii) to the test the effectiveness of Indicator of Reduction in Soil (IRIS) tubes to indicate the reduction of S. The study examined the following parameters from April 6 to July 21, 2013: (i) the HGM of Scotts Creek Marsh, (ii) soil oxidation and reduction (redox) conditions, …

Stratigraphy Of Quaternary Dunes By Sand Mineralogy And Pedogenic Features, Los Osos, California, Lyssa A. Cousineau

Master's Theses

The goal of this study was to assess mineralogy and pedogenic features of sand dunes in a stratigraphic sequence. The purpose was to determine whether these features significantly differ to reflect age differences with depth within the sequence. This study was conducted in Montaña de Oro State Park, located on the central Californian coast eighteen kilometers northwest of San Luis Obispo in San Luis Obispo County.

Samples were collected from the vertical exposure of one dune face by stratified random sampling at 1.0-m vertical intervals. Particle size distribution was determined through particle-size analysis by hydrometer and sieve. Electrical conductivity and …

The Spatial Distribution Of K-Factor Values Across A Toposequence And A Soil Survey Map Unit, Jacqueline Elizabeth Tilligkeit

Master's Theses

Rivers and streams are adversely affected by an increase in sedimentation in their waters from eroding land. High sediment loads in streams can bury fish eggs and prevent hatching, increasing nutrients in the water causing algae blooms, or even contaminating the water with heavy metals carried in or on the aggregates. The erodibility of soil is valuable knowledge to all land users so that we may predict soil loss and its potential to pollute streams. This is done by using the Revised Universal Soil Loss Equation (RUSLE). By predicting soil loss from a given landscape, land managers can take mitigation …

Strawberry Growth, Yield, Fruit Nutrition, And Control Of Verticillium Wilt With Pre-Plant Soil Fumigants, Ozone, And Biological Control, Justin J. Scurich

Master's Theses

Verticillium wilt is a widespread soilborne disease of strawberry historically controlled by soil fumigation with methyl bromide (MB). MB was banned by the United Nations in 1995 and will be completely phased out by 2015. Research has concentrated on alternative methods of disease control without finding a single alternative able to replace MB in widespread disease control and yield increase. For the current study, strawberries were greenhouse grown in container pots filled with soil from both infested and non-infested areas of a commercial strawberry field in Watsonville, CA. Treatments included pre-plant soil fumigation with commercially available formulations of methyl bromide, …

Evaluating Geomorphic Change In Little Creek Using Repeated Cross-Sectional And Longitudinal Profile Surveys, Drew Allen Perkins

Master's Theses

Six geomorphic study reaches were established in 2002 along a forested mountain stream (gradients range from 0.02 to 0.05) on Cal Poly's Swanton Pacific Ranch in Santa Cruz County, California. These study reaches are a component of paired and nested watershed studies in the approximately 500 hectare Little Creek watershed. The overall goal of this study was to monitor water quality and channel conditions before, during, and after a selective harvest of redwood. A selective harvest occurred in the North Fork of Little Creek in Summer 2008. In August 2009, approximately 90% of the Little Creek Watershed was burned in …

Quantification Of Nitrate Sources And Sinks Using A Water Quality Network In Morro Bay Estuary, California, Johanna Nadia Jean Weston

Master's Theses

Using an instrumented water quality network in Morro Bay Estuary, California from 2007 to 2010 (15 min sampling frequency), this study addressed the two objectives of constructing a nitrate budget and assessing the influence of sampling frequency on water quality parameters. These two objectives led to the submission of an original report of research (Appendix A) and a note (Appendix B) to peer-reviewed journals.

The first objective was to characterize the high spatial and temporal variation in physical parameters and nitrate concentrations and to construct a nitrate budget quantifying sources and sinks of nitrate from the ocean, streams, and groundwater, …

Effects Of High-Density, Short-Duration Planned Livestock Grazing On Soil Carbon Sequestration Potentials In A Coastal California Mixed Grassland, Kristina Michelle Wolf, Marc Horney, Brent Hallock, Robert T. Rutherford, Anthony T. O'Geen, Royce Larsen, William Plummer

Master's Theses

Planned grazing management in rangelands may improve carbon sequestration potential of soils by increasing plant biomass and the rate of nutrient cycling, which might mitigate global warming. The effects of high-intensity, short-duration planned grazing of sheep on several soil and ecosystem properties were investigated on a mixed grassland in San Luis Obispo, CA. The objectives of this study were to (a) identify soil properties related to soil C sequestration in rangelands; (b) determine if planned grazing improved soil carbon sequestration; (c) quantify changes in identified variables in grazed and rested plots; and (d) analyze any changes in plant species composition …

Go Farm, Goleta: Urban Agriculture Protection For Eastern Goleta Valley, Eli M. Krispi

Master's Theses

This paper explores two potential land use planning strategies that can be used to preserve and enhance the economic viability of agricultural operations surrounded by suburban development in Santa Barbara County’s Eastern Goleta Valley: buffers between agriculture and other land uses, and agritourism. In the case of buffers, academic literature is examined to determine how effective buffers are at various tasks (filtering runoff, mitigating dust and wind, providing habitat, etc.) and how to construct buffers to maximize their effectiveness. Land use plans and codes from several California jurisdictions are studied to see how buffers are put to use. Academic literature …

Probabilistic Fault Displacement Hazard Analysis For Reverse Faults And Surface Rupture Scale Invariance, Zachary E. Ross

Master's Theses

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A methodology is presented for evaluating the potential surface fault displacement on reverse faults in a probabilistic manner. This methodology follows the procedures put forth for Probabilistic Fault Displacement Hazard Analysis (PFDHA). Empirical probability distributions that are central to performing a PFDHA are derived from field investigations of reverse faulting events. Statistical analyses are used to test previously assumed properties of scale invariance with respect to magnitude for normalized displacement. It is found that normalized displacement is statistically invariant with respect to magnitude and focal mechanism, allowing for the …

Effects Of Recycled Water On Landscape Plants, Casey R. Miranda

Master's Theses

ABSTRACT EFFECTS OF RECYCLED WATER ON LANDSCAPE PLANTS Casey Ray Miranda Recycled water is water that has been previously used, has suffered a loss of quality, and has been properly treated for redistribution (Wu et al. 2001). The use of recycled water as an alternative to fresh water in the landscape can have positive and negative effects. Experimentation on 40 different plant species during a 32 week period (2 phases of 16 weeks), was conducted to analyze the effects of recycled water irrigation on the appearance of landscape plants. Each species of plant was planted into 10 individual number 2 …

Remediation Of Soil Hydrophobicity On A Coastal Usga Sand-Based Golf Green, Troy David Thompson

Master's Theses

Managing soil hydrophobicity caused by localized dry spots (LDS) on sand based golf greens has become one of the greatest challenges for golf course superintendents and managers, especially as water restrictions intensify. The purpose of this study was to evaluate the effectiveness of thirteen soil surfactants in eliminating LDS and in maximizing root zone soil moisture on a sand based USGA golf green located on the California Central Coast. Potential water repellency of air dried cores (measured utilizing the water droplet penetration time (WDPT) method), phytotoxicity, and climate were analyzed during two experimental trials. Phytotoxicity data was collected for Trial …

Comparison Of Two Potential Streamgage Locations On Scott Creek At Swanton Pacific Ranch, California, Matthew C. Scrudato

Master's Theses

Two locations on Scott Creek, located 12 miles north of Santa Cruz California, are being considered for the installation of a streamgage to measure discharge. Each location offers unique considerations and challenges in gage construction and discharge measurement capabilities. A detailed flood frequency analysis was completed using a direct watershed comparison, direct equations developed by Waananen and Crippen, a Log Pearson Type III Frequency Distribution, a regional analysis, and two-station comparisons. Final results indicate a 100-year recurrence interval of 6,310 ft3/s at the Upper Scott Creek location and 6,520 ft3/s at the lower location. A detailed indirect measurement revealed that …

Implementation Of Sustainable Management Practices At Two California Central Coast Vineyards And Their Effects On Soil Fertility, Dawn M. Stimson

Master's Theses

Implementation of Sustainable Management Practices at Two California Central Coast Vineyards and Their Effects on Soil Fertility

Dawn Michelle Stimson

“Sustainable agriculture” has gained increased popularity in recent years. This study was conducted to determine the effects of sustainable management practices on soil fertility at two California Central Coast vineyards. The effects of cover crops (Erosion Control Mix - blando brome [Bromus hordeaceus], hykon rose clover [Trifolium hirtum All.], and zorro annual fescue [Vulpia mourns]), green waste compost (Forest Blend), and reduced tillage on soil fertility were investigated in San Luis Obispo, California on a clay and sandy loam soil. …