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Combating Fungal Pathogens (Helminthosporium Solani, Pythium Ultimum) With Secondary Metabolites Of Streptomyces Bacteria, Erik W. Kemp

Theses and Dissertations

Fungal diseases, Pythium ultimum (Pythium leak) and Helminthosporium solani (silver scurf) have detrimental effects on potato tuber (Solanum tuberosum) quality and yield. Tubers are the world’s fourth largest agricultural food crop and are crucial for feeding a growing population. Bacteria from the genus Streptomyces are known for producing a wide variety of secondary metabolites with antifungal properties. Isolates of Streptomyces have recently shown inhibitory effects towards P. ultimum and H. solani in Petri dish assays. These data suggest that Streptomyces may work as a biocontrol to protect tubers from P. ultimum and H. solani. We tested talc-based powder formulas for …

Hybrid Bermudagrass And Kentucky Bluegrass Response Under Deficit Irrigation In A Semi-Arid, Cool Season Climate, Hanna R. Burgin

Theses and Dissertations

As average global temperatures rise, cool-season C3 turfgrasses, such as the most commonly grown Kentucky bluegrass (Poa pratensis L.; KBG), struggle to tolerate extreme summer heat and increase their water consumption. Hybrid Bermudagrass (Cynodon dactylon [L.] Pers. × Cynodon transvaalensis Burtt Davy; HBG) is a warm-season C4 grass that may be increasingly suited for northern ecosystems traditionally classified as transition or cool-season climate zones. Glasshouse and field studies were conducted to compare HBG and KBG water use. The objective of the glasshouse study was to evaluate plant health and growth for two HBG cultivars (‘DT-1’ and ‘NorthBridge’) compared to a …

Lymphocyte Proteomics For Monitoring Long Term Immune System Dynamics, Michaela Mccown

Undergraduate Honors Theses

Time dependent change in lymphocytes provides a necessary background for monitoring the development of Chronic Lymphocytic Leukemia from asymptomatic to malignant. Several bulk proteomics studies characterize differences between tumor cells and healthy B cells, yet the transition to symptomatic disease is not well understood. This could be shown by a longitudinal study beginning with asymptomatic patients if the rare tumor cells in early stages can be isolated from small volume blood draws and effectively characterized with few cells, such as was done here using healthy B cells to provide a baseline for such studies to discriminate routine fluctuation from pathogenic …

Spatiotemporal Analysis Of Variability In Soil Volumetric Water Content And Spatial Statistical Methods For Management Zone Delineation For Variable Rate Irrigation, Isak Lars Larsen

Theses and Dissertations

Irrigated agriculture is the largest user of freshwater in a world experiencing increased water scarcity and water demands. Variable rate irrigation (VRI) aims to use water efficiently in crop production, resulting in good yields and water conservation. With VRI, the grower is able to employ custom irrigation rates for different parts of a field. Adoption of VRI has been limited due to the complexity of matching irrigation to spatiotemporal crop water needs and the cost/benefit economics of VRI equipment. The goal of this study was to quantify spatiotemporal variability of VWC in a field that has uniform soil type and …

Improving Rangeland Seedling Recruitment Using Fungicide Seed Coatings And Golden Eagle Reproductive Success In Relation To Explosive Military Tests And Trainings, Benjamin William Hoose

Theses and Dissertations

The objective of the first chapter of this thesis was to determine whether fungicide seed coatings constitute an effective strategy for increasing seedling recruitment in restoration scenarios in the Intermountain West. We tested a mixture of four fungicides that address potential fungal pathogens to bluebunch wheatgrass, a dominant bunchgrass that is commonly used in restoration. Across two sites and three years, we found that the fungicide seed coating increased emergence in five of the six sites and years, with an average increase of 59.1% over the control. There was a strong interaction (P < 0.001) between the effects of fungicide treatment, the year and the site on emergence. This interaction was likely related to the effects of the hydrothermal microsite environment on disease severity. Further research is necessary to fully understand the conditions under which fungicide seed coatings are most likely to be effective. The objectives the second chapter of this thesis were to 1) estimate the effects of golden eagle nest proximity to explosive disturbances on reproductive success given other relevant habitat variables (e.g. indices of topography and vegetation), and 2) determine the relative importance of nest proximity to explosive disturbances as a predictor of golden eagle reproductive success compared to other relevant habitat variables. Reproductive success data were collected from nesting territories within and surrounding land controlled and managed by the US Department of Defense. We fit the reproductive survey data using generalized linear mixed-effects models comprised of unique, hypothesis-based sets of habitat variables. We compared the models using AICc-based model selection processes. Given the best approximating model, we found no evidence that the likelihood of reproductive success was affected by nest proximity to explosive disturbances (P = 0.460). We further found nest proximity to explosive disturbances consistently ranked in the bottom 50% of relative variable importance. These results may indicate golden eagle tolerance or habituation to explosive military tests and trainings. Although the two chapters of this thesis are disjointed, they are loosely unified by the ecological importance of disturbance, invasive species, and restoration within the Great Basin ecoregion.

Soil Water Dynamics Within Variable Rate Irrigation Zones Of Winter Wheat, Elisa Anne Woolley

Theses and Dissertations

Understanding the spatial and temporal dynamics of soil water and crop water stress within a field is critical for effective Variable Rate Irrigation (VRI) management. Proper VRI can result in improved protection of the crop from early onset of crop water stress while minimizing runoff and drainage losses. The objectives of this study are (1) to examine zone delineation for informing irrigation recommendations from volumetric water content (VWC) and field capacity (FC) to grow similar or greater wheat yields with less water, (2) evaluate the ability to model soil and crop water dynamics within a season and within a field …

Movements And Space-Use Of Female Greater Sage-Grouse (Centrocercus Urophasianus) During Nesting And Breeding Seasons, Drew W. Retherford

Theses and Dissertations

Greater sage-grouse (Centrocercus urophasianus) are a species of conservation concern throughout their range including the state of Idaho. Little is known about the size of areas used by female sage-grouse during the breeding and nesting seasons, fidelity of females to those areas, or fidelity of female sage-grouse to specific leks or nest sites. The recent miniaturization of global positioning system (GPS) transmitting devices allows for a more thorough analysis of this behavior. We placed GPS transmitters on 234 female sage-grouse in Idaho, USA, from 2015 to 2019. We monitored 145 nest attempts, 15 of which occurred in consecutive years, from …

Human Health And Economic Costs Of Air Pollution In Utah: An Expert Assessment, Isabella Errigo

Undergraduate Honors Theses

Recent scholarship has found that air pollution damages our health and economy more than previously understood, with approximately one in four deaths associated with exposure to air pollution globally. However, translating these research findings into policy and behavior change at local levels remains a major challenge, partially because of mismatch between the scale of air pollution research (often national or global) and governance frameworks (typically local to regional). Here, we used an expert assessment to bridge this research-policy divide in Utah, USA. We combined quantitative and qualitative input from 23 Utah-specific researchers and specialists, asking for estimates of human health …

Bottom-Up Controls (Micronutrients And N And P Species) Better Predict Cyanobacterial Abundances In Harmful Algal Blooms Than Top-Down Controls (Grazers), Scott Andrew Collins

Theses and Dissertations

The initiation, bloom, and bust of harmful Cyanobacteria and algae blooms (HAB) in lakes are controlled by top-down and bottom-up ecological controls. Excess phosphorous and nitrogen inputs from anthropogenic sources are primary to blame, but eukaryotic grazers may also promote or curb Cyanobacteria dominance. We tracked shifts in bacterial composition, lake chemistry, and eukaryotic grazing community weekly or bi-weekly through spring and summer and modeled the causes of specific Cyanobacterial species blooms and busts across three lakes in Utah, USA, with differing lake trophic states. Regardless of trophic status, all three lakes experienced blooms of varying composition and duration. Aphanizomenon …

Landsat Collections Reveal Long-Term Algal Bloom Hot Spots Of Utah Lake, Rachel Shanae Tate

Theses and Dissertations

Harmful algal blooms (HABs) and nuisance algal blooms (NABs) are a worldwide phenomenon with implications for human health and safety. HABs occur when algae or bacteria grow in high enough densities to harm animals and humans. A primary component of harmful algal blooms is cyanobacteria, which are aquatic, photosynthesizing microorganisms that produce toxins at high concentrations. Cyanobacterial biomass has increased worldwide in recent decades, raising concern about the future of fresh- and marine-water systems in a changing climate. Understanding the patterns and conditions of past algal blooms can provide useful insights for managing future blooms. Remote sensing can enhance our …

Of Fire, Mammals, And Rain: Mechanisms Of Plant Invasions, Tara Boyce Bishop

Theses and Dissertations

Biological invasions are driving environmental state changes on a global scale. Exotic plant species must be successful at passing several abiotic and biotic filters to establish and disrupt the native plant community assembly. Understanding where exotic plants are on a regional scale and being able to characterize how exotic plants are generally interacting with their environment is crucial information for exotic species management (chapter 1). In the western United States human-related activities are augmenting the spread of exotic plant species by increasing the ignitions of wildfire. Wildfire can lead to nutrient pulses through the removal of intact native communities and …

Use Of Plant Growth Regulators To Expand The Period Of Sagebrush Seed Germination And Reduce The Risk Of Restoration Failure: Laboratory Trials, Chelsea Elizabeth Keefer

Theses and Dissertations

Seed germination during unhospitable environmental conditions can be a major barrier to direct seeding efforts in dryland systems. In the sagebrush steppe, Artemisia tridentata Nutt. ssp. wyomingensis and Artemisia arbuscula are important shrub species that are being used in restoration, but seeding success is highly sporadic due to inter-annual and intra-seasonal weather variability. Altering and expanding the period of germination, as a form of bet-hedging, may improve plant establishment. Our objective was to determine if we could expand the period of germination using plant growth regulators (PGRs) applied in a conglomerated seed coating treatment. In a laboratory study, the seed …

Whole-Genome Assembly Of Atriplex Hortensis L. Using Oxfordnanopore Technology With Chromatin-Contact Mapping, Spencer Philip Hunt

Theses and Dissertations

Atriplex hortensis (2n = 2x = 18, 1C genome size ~1.1 gigabases), also known as garden orach, is a highly nutritious, broadleaf annual of the Amaranthaceae-Chenopodiaceae family that has spread from its native Eurasia to other temperate and subtropical environments worldwide. Atriplex is a highly complex and polyphyletic genus of generally halophytic and/or xerophytic plants, some of which have been used as food sources for humans and animals alike. Although there is some literature describing the taxonomy and ecology of orach, there is a lack of genetic and genomic data that would otherwise help elucidate the genetic variation, phylogenetic position, …

Hydrologic And Biologic Responses Of Anthropogenically Altered Lentic Springs To Restoration In The Great Basin, Leah Nicole Knighton

Theses and Dissertations

Water is a limited and highly valued resource in the semi-arid Great Basin. Surface water sources are often small and widely spaced apart, comprising only 1-3% of the surface area of the overall landscape. Despite their small size, these springs and surrounding wet meadows have a substantial effect on the surrounding environment. Springs provide drinking water, forage and cover for livestock and wildlife, habitat for diversity of plant species and a resource for human-related activities. In recent years, many of these springs have become dewatered due to diversions of groundwater for municipal water and agriculture, and climatic shifts in precipitation …

A Metagenomic Approach To Understand Stand Failure In Bromus Tectorum, Nathan Joseph Ricks

Theses and Dissertations

Bromus tectorum (cheatgrass) is an invasive annual grass that has colonized large portions of the Intermountain west. Cheatgrass stand failures have been observed throughout the invaded region, the cause of which may be related to the presence of several species of pathogenic fungi in the soil or surface litter. In this study, metagenomics was used to better understand and compare the fungal communities between sites that have and have not experienced stand failure. Samples were taken from the soil and surface litter in Winnemucca, Nevada and Skull Valley, Utah. Results show distinct fungal communities between Winnemucca and Skull Valley, as …

The Genome Of Cañahua: An Emerging Andean Super Grain, Hayley Jennifer Mangelson

Theses and Dissertations

Chenopodium pallidicaule, known commonly as cañahua, is a semi-domesticated crop grown in high-altitude regions of the Andes. It is an A-genome diploid (2n = 2x = 18) relative of the allotetraploid (AABB) Chenopodium quinoa and shares many of its nutritional benefits. Both species contain a complete protein, a low glycemic index, and offer a wide variety of nutritionally important vitamins and minerals. Due to its minor crop status, few genomic resources for its improvement have been developed. Here we present a fully annotated, reference-quality assembly of cañahua. The reference assembly was developed using a combination of established techniques, including multiple …

Evaluating Nitrogen And Carbon Differences In Standing Litter From Normal And Prematurely Senesced Bromus Tectorum Plants, Alexa Lunt Jensen

Theses and Dissertations

Bromus tectorum, an invasive winter annual, has displaced native vegetation throughout the western United States. Bromus tectorum litter influences nutrient cycling near the soil surface as well as plant establishment. Failed seed production of B. tectorum occasionally occurs in the field, with plants exhibiting weak flowering culms that turn straw-colored in spring when normal plants are green or purple in color. Because annual grasses transport most soluble carbon (C) and nitrogen (N) to reproductive organs, seed production failure results in significantly different fates for these nutrients compared with normal plants. As part of larger efforts to understand events leading to …

The Effects Of Dixie Harrow Treatments On Greater Sage-Grouse Resource Selection And The Nutritional Value Of Sagebrush During Winter, Jason Alan Wood

Theses and Dissertations

Sagebrush (Artemisia spp.) is an important source of food and cover for many animals, especially during winter months. Understanding how wildlife species respond to sagebrush management actions can help improve conservation planning. Dixie harrow is a method of improving spring/summer habitat for many herbivores by reducing sagebrush cover to stimulate the growth of grasses and forbs. These treatments, however, may influence the quantity and quality of sagebrush available to greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) during winter. We evaluated the effects of Dixie harrow on sage-grouse resource selection during winter (Chapter 1) and on the nutritional value of sagebrush (Chapter …

Impacts Of Novel Fire And Herbivory Regimes On Snow-Waterresources And Resilience Of Aspen Forests, Jordan Daniel Maxwell

Theses and Dissertations

Human activities and expansion have created novel disturbance patterns across Earth’s landscapes. Disturbance is an ecological interruption after which ecosystem recovery or transition into a new state can occur, affecting biodiversity, ecosystem functioning, and theavailability of ecosystem services. Fire and herbivory are two of the most widespread forces of disturbance which shape ecosystems globally. In temperate forest ecosystems, fire affects forest composition, which influences the diversity and resilience of ecosystems (chapters 1 and 2) and forest canopy structure, which is important to snowpack accumulation and the availability of water resources (chapters 3 and 4). In chapter one, the effects of …

Evaluating Fungal Pathogen Inoculum Loads In Field Seed Banks, Taryn Lori Williamson

Theses and Dissertations

Quantification of soilborne pathogen inoculum loads is important in both agricultural and wildland settings. Quantitative Polymerase Chain Reaction (qPCR) methods using SYBR Green chemistry have been shown to be useful for quantifying fungal inoculum loads in environmental samples. The purpose of this study was to develop a method to quantify fungal pathogen inoculum loads in soil seed banks using a qPCR method with SYBR Green chemistry. The invasive annual grass Bromus tectorum was chosen for this seed bank study. There were three objectives: 1) to design target-specific primers for three fungal pathogens known to be important in Bromus tectorum seed …

Composition Of The Community Of Small Mammals In The Great Basin Desert, Samantha Elizabeth Phillips

Theses and Dissertations

Small mammals are a keystone guild in arid ecosystems; often exhibiting top-down control of the diversity and structure of plant communities. However, changing climate, shifting fire regimes, and the invasion of exotic plants are modifying the structure of arid systems. Environmental changes in these arid systems are likely altering small mammal communities, and therefore, their ecological role. We examined two aspects of the community composition of small mammals in the Great Basin: changes in community composition since large scale sampling of the region began in 1930, and the current population of a sensitive species of small mammal, the dark kangaroo …

An Ecological And Distributional Analysis Of Great Basin Bristlecone Pine (Pinus Longaeva), Gregory Watson Taylor

Theses and Dissertations

Understanding the impacts of climate change is critical for improving the conservation and management of ecosystems worldwide. Ecosystems vary along a precipitation and temperature gradient, ranging from tropical jungles to arid deserts. The Great Basin is a semi-arid eco-region that is found within the western United States. Plant communities within the Great Basin range from sagebrush valleys to sub-alpine conifer forests found at high elevation areas. It is predicted that the Great Basin will experience prolonged periods of drought, more intense fires, and greater variability in average annual and monthly precipitation, all in response to changes in climate patterns. At …

Exploration Of The Gossypium Raimondii Genome Using Bionano Genomics Physical Mapping Technology, Christopher Jon Hanson

Theses and Dissertations

Cotton is a crop with a large global economic impact as well as a large, complex genome. Most industrial cotton production is from two tetraploid species (Gossypium hirsutum L. and Gossypium barbadense L.) which contain two subgenomes, specifically the AT and DT subgenomes. The DT subgenome is nearly half the size of the AT subgenome in tetraploid cotton and is closely related to an extant D-genome Gossypium species, G. raimondii Ulbr. Characterization of the structural variants present in diploid D-genome should provide greater insight into the evolution of the DT subgenome in the tetraploid cotton. Bionano (BNG) optical mapping uses …

Characterizing The Spatial Variation Of Crop Water Productivity For Variable-Rate Irrigation Management, Jeffrey David Svedin

Theses and Dissertations

Irrigated agriculture is the primary consumer of limited worldwide freshwater resources. Drought, growing world populations, and environmental demands compete with irrigation for freshwater resources"”threatening sustainable global food, fuel, and fiber production. This escalating global crisis demands that agriculture produce more food using less water. Traditional irrigation management has used technology to apply uniform irrigation rates across landscapes"”ignoring natural environmental variation. This provides inherent inefficiencies of over- or under- irrigation within individual fields. Variable-rate irrigation (VRI) is modern technology that employs global positioning systems and geographic information systems to match irrigation to spatially variable crop water demands within a field. Although …

Plane Of Energy Nutrition On Blood Metabolites, Milk Production And Lamb Growth In Friesian Sheep, Rebekah Paige Jensen

Theses and Dissertations

Small ruminant species are utilized for their diverse products including meat, dairy products, and wool. Effective and humane management are essential to maintain high production rates and comfortable animals. To attain this objective, managers needs to have an extensive knowledge of husbandry techniques, understanding of physiological processes, and familiarity with nutritional requirements. We examined the effects of varying feed components on two different ruminal species. In Chapter 1, we conducted a study to evaluate"¯the effects"¯of a low metabolizable energy (LME) and high metabolizable energy (HME) diet on twenty-two Friesian/Lacuane"¯cross ewes and lamb nutritional status."¯Effects on milk production during early lactation …

Plant Functional Groups And Success In A Changing Environment: Modeling Physiological Niches Of Colorado Plateau Plants, Anne Thomas

Undergraduate Honors Theses

Quantifying the environmental and physiological niches of plant species is crucial to predicting their sensitivity to global change, and aggregating plant species by functional type is fundamental both to ecological theory and to the practicality of large-scale efforts to predict the consequences of global change. However, traditional functional types are not always predictive of individual species’ responses to change. Here, an inverse species distribution modeling approach is used to identify functionally similar species based on physiological niche in order to better anticipate the consequences of climate change on the Colorado Plateau, USA. The Colorado Plateau is a semiarid region particularly …

Microbial And Co2 Responses To Water Stresses Show Decreased Productivity And Diversity Through Time, David Michael Robinson

Theses and Dissertations

Some bacterial taxa when stimulated by water additions will break dormancy, grow, and become dominant members of the community and contribute significant pulses of CO₂ associated with the rewetting event. These pulses of activity are associated with high levels of bacterial productivity in soils. (Aanderud et al. 2011) We examined the bacterial taxa that resuscitate and become metabolically active following two forms of water stress (soil drying-rewetting and freeze-thaw cycles) and we captured and measured the CO₂ emanating from those soils. Specifically, We used target metagenomics, which uses a specific gene pool within bacteria that is associated with …

Landscape Foundations: A Practical & Technical Guide To Landscape Maintenance, Marco Crosland

Undergraduate Honors Theses

Many homeowners struggle to maintain healthy landscapes. Often, they simply don’t understand basic principles that, if followed, would make a significant difference in the health and appearance of their landscape. The hope of Landscape Foundations is to help homeowners maintain healthy and excellent landscapes by teaching these “correct principles”.

What makes Landscape Foundations different than other landscape guides is that it brings in current research and explains it in a simple way. This guidebook provides pictures and additional resources to explain landscape maintenance principles. It teaches both the practical and technical sides.

Landscape Foundations is written for both beginners and …

Testing The Potential Of Novel Grain Crop Cultivation In Rural Malawi During The Dry Season Through Irrigation And Soil Modification, Jessica Truman

Undergraduate Honors Theses

This research project studied the germination and growth rates of oat and quinoa crops in Mtalimanja, Malawi. This project was part of a larger effort by General Mills and Brigham Young University researchers to increase the diversity and nutrient content of crops in impoverished countries worldwide. It was conducted from May to August 2017 during Malawi’s dry season. Tetraploid oats and quinoa, both modified to increase the protein content of harvested grains, were planted under three different soil conditions: unamended soil, soil mixed with composted chicken litter, and soil with surface-applied granular fertilizer. The research plots were watered daily except …

Survival Of Neonate Mule Deer Fawns In Southern Utah: Effects Of Coyote Removal And Synchrony Of Parturition, Jacob Tyler Hall

Theses and Dissertations

Mule deer (Odocoileus hemionus) are an iconic species of wildlife, and populations of mule deer across much of the western U.S. have experienced recent fluctuations in size. Factors that affect the survival and subsequent recruitment of juveniles may be the preeminent cause of population fluctuations for mule deer in many areas. Many factors, including habitat loss, extreme weather, intense predation, timing and synchrony of parturition, and competition with other species may be influencing these changes. We studied two potential factors that can influence the survival of neonate mule deer in southern Utah. To better understand how predation affects …