Modifying Succession: A History Of Vegetation Alliances On Swanton Pacific Ranch, Jill Wilson O'Connor

Master's Theses

This thesis conducts historical research into Swanton Pacific Ranch in the County of Santa Cruz, an interdisciplinary facility for education and research managed by Cal Poly’s College of Agriculture, Food and Environmental Sciences. The study seeks to determine whether there have been discernable changes in vegetation alliances (communities), spatially or in type, within a 110-acre Study Area from the early twentieth century to the present day and how the changes compare with other similar historical analyses in California. Historical farming and ranching uses of the area are researched, and two family case studies are presented as paradigms of potential changes …

Influence Of Shaded Conditions On Development Of Asteraceae Species Native To Kansas, Aline Rodrigues De Queiroz

Master's Theses

to the heterogeneity of habitats, all plants are exposed to at least some degree of shade during their lifetime. Reduced light intensity, drops in R:FR ratio, and limited blue light are cues for plants to perceive competition; the shade avoidance syndrome (SAS) is common for grassland species while shade tolerance (ST) is common for forest species when competition is perceived. SAS is characterized by elongation of stems and petioles, reduced branches, decreased leaf area, decreased shoot biomass, and increased number of ramets. ST is characterized by little elongation of stems and petioles, high chlorophyll content and high chlorophyll a/b ratio …

Greening Rates And Photosynthetic Development Of Leaves In C3 And C4 Plants, Tayler J. Kriss

Master's Theses

To study chlorophyll development time and overall photosynthetic development in C3 and C4 leaves, seeds were germinated in complete darkness and achlorophyllous leaves were then allowed to develop in lighted conditions. Corn (Zea mays, C4), sorghum (Sorghum bicolor, C4), green bean (Phaseolus vulgaris, C3), broad bean (Vicia faba, C3), and wheat (Triticum aestivum, C3) were investigated for the first ten days of sunlight exposure. Chlorophyll concentration, chlorophyll fluorescence, and CO2 gas exchange measurements were conducted daily on the first leaf that emerged after the embryonic leaves of each plant. The first five days of the experiment, days zero to four …

Effect Of Evapotranspiration Rate On Almond Yield In California, Dafne Isaac Serrano

Master's Theses

Since 2011, California has been under drought conditions. These conditions have not only affected water availability for farmers, but also production. California’s second most valuable crop, almonds, has been affected by drought conditions. This study used three models (Model 1-3) to describe almond yield variability from year to year and almond yield variability within a year in Kern County, CA. The study evaluated 185 almond farms that were classified in three locations (east side, west side and north west side). The years of the study were 2011 (wet year) and 2013-2015 (drought condition years). Model 1 determined a functional regression …

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 …

Effect Of Aquaponic Vs. Hydroponic Nutrient Solution, Led Light Intensity And Photoperiod On Indoor Plant Growth Of Butterhead, Romaine And Kale (L. Sativa, B. Oleracea), Sean M. Foster

Master's Theses

Vertical farming has been proposed as a solution for providing food security for an increasing, urbanized human population. Light-emitting diode (LED) technology has become increasingly affordable and efficient, making it an ideal choice as artificial lighting for indoor farms. Still largely undiscovered parameters are the optimal plant varieties and types of production systems for plant growth, profit, and human nutrition. Aquaponics may be able to provide sustainable animal protein for vertical farms, increasing their ability to provide more substantial nutrition to consumers. This research aimed to better understand vertical farming as a food production system, and to determine if aquaponics …

Factors Affecting The Regrowth Of Ilex Glabra In A Routinely Burned Longleaf Forest, Jaybus Price

Master's Theses

This study examines the effects of historical management by use of prescribed fire on Ilex glabra stems/m² and factors affecting the regrowth of I. glabra after a prescribed burn to gain beneficial knowledge for management purposes. Environmental factors and morphological parameters of I. glabra were sampled before and after a prescribed burn of the Longleaf Trace Nature Preserve in September 2016. The study site is located in Lamar County, Mississippi, just west of Hattiesburg, MS. Stem densities of I. glabra were collected once before the prescribed burn and twice after the prescribed burn at 2 month and 9 month …

Interplay Of Dgat1, Pdat1 And Dgat2 Enzymes In Plant Triacylglycerol Assembly, Anushobha Regmi

Master's Theses

Acyl-CoA:diacylglycerol acyltransferase (DGAT) catalyzes the transesterification of fatty acid from acyl-CoA to diacylglycerol (DAG) forming triacylglycerol (TAG, a.k.a oils and fats). Most plants have at least two unrelated DGAT genes, DGAT1 and DGAT2. Plants predominantly express only one during oil synthesis; the reason, however is not clear. A few studies have indicated that each enzyme prefers DAG and acyl-CoA substrates with different fatty acid compositions. Industrially desirable seed oil composition can be obtained through genetic engineering by replacing the endogenous enzyme with one that has different substrate selectivity. In Arabidopsis thaliana, DGAT1 and another unrelated enzyme PDAT1 are essential …

Characterization Of Botrytis Cinerea Resistance To Fungicides In California Strawberry Production, Scott D. Cosseboom

Master's Theses

Gray mold of strawberry, caused by Botrytis cinerea, is a very destructive pre- and post-harvest fruit rot. Outside of California, fungicide resistance in B. cinerea has been reported to every site-specific chemical class labeled for use against gray mold. One objective of this study was to characterize the resistance of 888 isolates of B. cinerea from California strawberry fields to ten active ingredients. Isolates were collected from the same planting block in 47 fields during the early-season (0 to 8 fungicide applications) and late-season (16 to 26 fungicide applications) of 2016. Sensitivity of each isolate was determined using the …

A Comparative Analysis Of The Nutrient Composition And Digestibility Of California Perennial And Annual Grasses At Four Stages Of Growth, Elaina Cromer

Master's Theses

Beef products represent the fourth largest agricultural commodity in the state of California, valuing more than $3 billion from 2013 to 2015 (CDFA, 2016) and procure 90% of the income for the range livestock industry (FRAP, 2003). Forages found on California’s coastal, desert, foothill, and mountain ranges are the basis of the state’s beef cattle industry. Understanding their nutritional quality of these forages is important for their effective use (George et al., 2001a; Waterman et al., 2014). The objectives of this research were to investigate the nutritional characteristics, and in situ digestbilities in Angus beef cattle, of common California annual …

The Population Genetics Of Morro Bay Eelgrass (Zostera Marina), Julia Gardner Harencar

Master's Theses

Seagrass populations are in decline worldwide. Zostera marina (eelgrass), one of California’s native seagrasses, is no exception to this trend. In the last 8 years, Morro Bay, California has lost 95% of its eelgrass. Eelgrass is an ecosystem engineer, providing important ecosystem services such as sediment stabilization, nutrient cycling, and nursery habitats for fish. The failure of recent restoration efforts necessitates a better understanding of the causes of eelgrass decline in this estuary. Previous research on eelgrass in California has demonstrated a link between population genetic diversity and eelgrass bed health, ecosystem functioning, and resilience to disturbance and extreme climatic …

Araucaria In The Urban Landscape: A Novel Leaning Pattern And Evidence Of Cultivated Hybridization, Jason W. Johns

Master's Theses

Our understanding of the natural world is constantly evolving and strengthening as more observations are made and experiments are performed. For example, we understand that tree stems grow toward the light (positive phototropism; Darwin 1880, Loehle 1986, Christie et al. 2013) and against gravity (negative gravitropism; Knight 1806, Hashiguchi et al. 2013). We also know that plants respond to mechanical stimulus and perturbation (thigmotropism; Braam 2005). Genes and their resulting proteins have been described to uncover some of the mechanisms for these environmental responses, but relatively speaking, we have just scratched the surface (Wyatt et al. 2013). While the discovery …

The Preservation And Protection Of Native Biodiversity In The Guadalupe Nipomo Dunes Complex, Lindsey M. Whitaker, Matthew Ritter, Scott J. Steinmaus, Jonathan Hall

Master's Theses

The Guadalupe Nipomo Dunes Complex (GNDC) is located within the California Floristic Province, a biodiversity hotspot characterized by high rates of endemism and exceptional loss of habitat. In 1980, the US Fish and Wildlife Service described the GNDC as, “the most unique and fragile ecosystem in the State of California,” and ranked it first on a list of 49 habitat areas needing state protection. It is the largest coastal dune area in California and it is one of the last remaining, relatively intact ecosystems of its type and size in the western United States. The growing recognition of species decline …

Genes Encoding Flower- And Root-Specific Functions Are More Resistant To Fractionation Than Globally Expressed Genes In Brassica Rapa, Naiyerah F. Kolkailah

Master's Theses

Like many angiosperms, Brassica rapa underwent several rounds of whole genome duplication during its evolutionary history. Brassica rapa is particularly valuable for studying genome evolution because it also experienced whole genome triplication shortly after it diverged from the common ancestor it shares with Arabidopsis thaliana about 17-20 million years ago. While many B. rapa genes appear resistant to paralog retention, close to 50% of B. rapa genes have retained multiple, paralogous loci for millions of years and appear to be multi-copy tolerant. Based on previous studies, gene function may contribute to the selective pressure driving certain genes back to singleton …

Investigating Novel Approaches For The Integrated Control Of The Soilborne Strawberry Pathogens Macrophomina Phaseolina And Fusarium Oxysporum F. Sp. Fragariae, Mel Carter

Master's Theses

Macrophomina phaseolina (Mp) and Fusarium oxysporum f. sp. fragariae (Fof) are emerging soilborne pathogens causing crown rot and Fusarium wilt, respectively, in commercial strawberry production in California. Fungicides representing eight active ingredients from four different mode of action groups (FRAC groups 1, 3, 7 and 12) were evaluated for their efficacy against each pathogen in vitro and each disease in planta. Fungicide active ingredients were evaluated for their ability to inhibit mycelial growth of both pathogens in vitro. Half-strength potato dextrose agar was amended with six different concentrations (0.01, 0.1, 1.0, 5.0, 10, 50 µg …

Evaluating The Myth Of Allelopathy In California Blue Gum Plantations, Kristen Marie Nelson

Master's Theses

It is widely accepted that allelopathy is not only significant, but more or less singular, in the inhibition of understory vegetation in California Eucalyptus globulus (blue gum) plantations. However, there is no published documentation of allelopathy by blue gums against California native species. Here, we present evidence that germination and early seedling growth of five California native species are not inhibited by chemical extracts of blue gum foliage, either at naturally-occurring or artificially concentrated levels. In the greenhouse, seeds were germinated in field-collected soil from mature blue gum plantations and the adjacent native, coastal scrub communities. In petri plates, seeds …

The Vascular Flora Of Wayne County, Mississippi, Daniel M. Mcnair

Master's Theses

The vascular flora of Wayne County, Mississippi, was surveyed from 2013–2015, and the species of native and naturalized plants are listed. In total, 1,135 species were identified from field collections, previously collected herbarium specimens, and field observations. These belong to 556 genera and 165 families. Four of these species represent first recorded occurrences in the state of Mississippi: Blyxa aubertii Rich., Gomphrena serrata Pav. ex Moq., Isoetes valida (Engelm.) Clute, and Polypogon interruptus Kunth. GPS coordinates are given for important collection sites representing the diversity of plant communities in the county. All voucher specimens from the survey are deposited in …

Predicting Invasive Range Of Eucalyptus Globulus In California, Anthony J. Lopez

Master's Theses

Eucalyptus globulus is the subject of intense debate in California. Its invasive potential, aggressive growth, reproductive biology, and association with fire make the prediction of spread important in California. Two modeling simulations, Climex and Maxent, will illustrate the distribution and potential growth range of E. globulus in California based on climate and presence. Modeling the potential range of growth will predict invasive spread. The anticipated result is the continued spread of E. globulus in coastal regions with adequate moisture and suitable climate. Predicting the range of E. globulus in California dictates management strategy and is key for preventing further introduction, …

The Effects Of Foliar Nutrient Applications On Split, Yield, And Internal Fruit Quality Of 'Wonderful' Pomegranate (Punica Granatum L.), John Matthew Chater

Master's Theses

Fruit split is the most important physiological disorder in pomegranate production, causing devastating crop losses worldwide. Foliar nutrient applications have been used experimentally to mitigate pomegranate fruit split but none have been conducted using the industry standard cultivar, Wonderful, and little is known about the effects of foliar nutrient applications on pomegranate. Additionally, investigations into putative health benefits of pomegranate fruit have increased interest in its production but limited evidence exists regarding effects of agricultural practices such as foliar fertilizer applications on internal fruit quality. ‘Wonderful’ pomegranate trees at 2 commercial orchards were treated with foliar applications of ZnSO_{4 …}

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

Increasing Expression Of Hepatitis B Surface Antigen In Maize Through Breeding, Erin Suzanne Miller

Master's Theses

The hepatitis B virus (HBV) is a common virus, with two billion people infected worldwide. It causes approximately 600,000 deaths each year, despite the availability of an effective vaccine since 1982. Maize as a platform for oral vaccination can supply a heat stable vaccine, which does not require syringes or trained personnel to administer. The Hepatitis B Surface antigen was transformed into maize and this seed was used to evaluate expression levels through the breeding process. The transgene was transferred into two elite maize inbreds by backcrossing. Highest expressing ears were selected each generation until approximately 99% commercial parent was …

Studies To Characterize Heavy Metal Content And Migration From Recycled Polyethyleneterephthalate, Michael John-Ross Whitt

Master's Theses

Packaging Materials account for 31% of the world’s municipal solid waste. Agencies like the Environmental Protection Agency (EPA) and the Agency for Toxic Substances and Disease Registry (ATSDR) are pushing for the increased use of recycled thermoplastic materials. Polyethylene terephthalate (PET) is a commonly recycled thermoplastic which is used to package ready-to-eat fruits and vegetables. Most recycled polyethylene terephthalate (RPET) packaging materials contain heavy metal catalysts, the most common being antimony. The recent increased use of recycled plastic materials has been suspected as the source of increased human heavy metal exposure. In this study, cadmium, chromium, nickel, lead and antimony …

Photosynthetic Thermal Tolerance And Recovery To Short Duration Temperature Stress In Desert And Montane Plants: A Comparative Study, David William Gallagher

Master's Theses

• Climate change models predict an increase in frequency and amplitude of extreme weather events, including heat waves. To better predict how the composition and distribution of plant assemblages might respond to these changes in temperature, it is important to understand how species currently respond to these extremes. Photosynthetic thermal tolerance (T₂₅)and photosynthetic recovery (RT₂₅) were quantified in 27 species. We also studied the relationships between T₂₅, RT₂₅ and leaf mass per area (LMA). Leaf temperature was also monitored in the field.
• Leaves used in this study were collected from two distinct …

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, …

Mortality Assessment Of Redwood And Mixed Conifer Forest Types In Santa Cruz County Following Wildfire, Steve R. Auten

Master's Theses

On August 12, 2009, the Lockheed Fire ignited the west slope of the Santa Cruz Mountains burning approximately 7,819 acres. Foresters and other land managers were left with challenging decisions on how to evaluate tree mortality. Big Creek Lumber Company, California Polytechnic State University, San Luis Obispo (Cal Poly)’s Swanton Pacific Ranch (SPR), and other resource professionals familiar with this region teamed up to develop a method for evaluating damage and thereby mortality for redwood, California nutmeg, live oak, tanoak, California bay, Pacific madrone, big leaf maple, Douglas-fir, Monterey pine, and knobcone pine. Quantitative damage criteria were used to design …

Aloe Striata Plant Defense Compounds Produced In Response To Jasmonic Acid, Salicylic Acid, And Eriophyid Mite Salivary Extract Elicitor Compounds, Fritz Light

Master's Theses

Aloe mites are herbivores of the genus Aloe (ALOACEAE) and are associated with hyperplastic growth in various aloe species, but the biochemistry of this interaction is poorly understood. In an effort to characterize plant defense responses to herbivory in the genus Aloe, a salivary extract was isolated from aloe mites (Aceria aloinis Keifer) and its bioactivity was tested using a hypocotyl elongation assay. Subsequently, Aloe striata plants were treated with jasmonic acid (JA), salicylic acid (SA), and the mite salivary extract. Using water and methanol, compounds of different polarity were extracted from aloe tissues that had been frozen …

Mapping Plant Biodiversity Hotspots At The County Scale: A New Tool For Establishing Resource Conservation Strategies, Kristie Haydu

Master's Theses

Myers first identified the world’s 25 biodiversity hotspots and pioneered innovative ideas about the usefulness of biodiversity models for establishing long-term resource conservation strategies at global scales. Since Myers, most of the subsequent studies using hotspot science for biodiversity modeling have used large spatial scales like countries, provinces or states, and other biogeoraphic regions. The California Floristic Province continues to be one of the recognized global biodiversity hotspots. Our study site, San Luis Obispo County is within this hotspot and we created a map of plant biodiversity hotspots at the county scale using GIS technology. We wanted to determine the …

Cholesterol Lowering Effects Of Milk With Added Phytosterols, Laura Kells Cusack

Master's Theses

Foods incorporating plant sterols (PS) reduce Low-density lipoprotein (LDL) on average approximately 10%. PS with a higher lipid solubility may promote greater reductions. We examined the cholesterol lowering effect of a novel triglyceride recrystallized phystosterol (TRP). Twenty subjects (mean ± SD; age, 56 ± 10 years; BMI, 27 ± 5) with elevated LDL (>100 mg/dL) participated in three 4-week phases; Phase I, 2% milk; Phase II, milk with 2.0 grams (g) free PS; Phase III, milk with 2.0 g TRP. Before and after each phase two fasting blood draws were obtained for determination of serum cholesterol. Between the 2% …

An Investigation Of Fraxinus Americana Branch Sway Using A 3 Dimensional Motion Capture System, Anna T. Campiformio

Master's Theses

Abstract

Wind is a dominant abiotic factor that a tree experiences throughout its lifetime and can cause severe tree damage, resulting in risk of injury to humans, and economic and ecological losses. It is thought that trees develop structural properties and architectures that help withstand loading conditions by dissipating wind energy through damping mechanisms. The role of branch motion in reducing potential dangerous wind loads has been the focus of relatively few studies. Even fewer studies have examined tree sway response to natural wind loaded conditions. In this investigation, branch frequencies were calculated for three Fraxinus americana using a three-dimensional …

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, …