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All Graduate Theses and Dissertations

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Trends In Us Crop Yields & Water Use, Britta L. Schumacher May 2021

Trends In Us Crop Yields & Water Use, Britta L. Schumacher

All Graduate Theses and Dissertations

Over half the land in the US is dedicated to agriculture, with the vast majority of all cropland cultivated in corn, wheat, or soybean. Despite continuing advances in agricultural technologies, and consistent yield growth over the twentieth century, research suggests that environmental change is already impacting agricultural yield and future changes are sure to exacerbate challenges to agricultural production. It follows that the future of US agriculture depends on the evolution of the changing climate, the relationship between crop yields and the environment, on-farm management and adaptations, the ecosystems that support agriculture, the political and economic incentives that shape what ...


Monitoring Populations And Movement Of Bobcats (Lynx Rufus) On The Eastern Slope Of The Sierra Nevada Mountains Of California, Michael Brown May 2021

Monitoring Populations And Movement Of Bobcats (Lynx Rufus) On The Eastern Slope Of The Sierra Nevada Mountains Of California, Michael Brown

All Graduate Theses and Dissertations

Monitoring the spatial ecology and population densities of carnivores is critical for effective management and conservation of these populations and the ecosystems in which they exist. However, effective monitoring of carnivore populations through estimates of space use, habitat selection and densities can be difficult due to their relatively low densities and wide ranging, elusive behaviors. Bobcats (Lynx rufus) are medium sized, top-level predators which are widely distributed across North America. Quantifying space use, habitat selection and developing effective population monitoring strategies for this species will have important implications for wildlife management.

My first objective was to use telemetry data to ...


Innovative Water Management Using Advanced Irrigation Systems And Biochar, Jonathan A. Holt May 2021

Innovative Water Management Using Advanced Irrigation Systems And Biochar, Jonathan A. Holt

All Graduate Theses and Dissertations

Two approaches to water optimization in agriculture are to increase soil water retention and improve the efficiency of irrigation. A soil amendment that has received attention for its ability to increase soil water retention is biochar, the remaining biomass after high C materials have been pyrolyzed (burned with limited oxygen and heat). Two studies were conducted at a total of 10 site-years in Utah from 2018 to 2020 to evaluate how wood biochar influences the productivity and crop quality of irrigated alfalfa (Medicago Sativa L.), corn (Zea mays L.), and wheat (Triticum L.), along with soil water tension. One study ...


Short- And Long-Term Mechanisms For Increasing Inputs Of Phosphorus In Mountain Waterbodies Of Northeastern Utah, Usa, Jessica Scholz May 2021

Short- And Long-Term Mechanisms For Increasing Inputs Of Phosphorus In Mountain Waterbodies Of Northeastern Utah, Usa, Jessica Scholz

All Graduate Theses and Dissertations

Phosphorus is an essential nutrient that allows life in water to flourish, but changes in phosphorus supplies are not well understood in remote watersheds. In mountain environments, remote watersheds contain critical high-quality water supplies and unique ecosystems, but excess phosphorus can diminish water quality by producing unfavorable aquatic species. Therefore, observed trends of increasing phosphorus concentrations in remote lakes and rivers in the US over the last two decades are a significant concern. Using the Uinta Mountains as a case study, we evaluated three different direct and indirect pathways for phosphorus increases in remote mountain watersheds that may explain observed ...


Responses Of Pacific Fishers To Habitat Changes As A Result Of Forestry Practices In Southwestern Oregon, Tessa R. Smith May 2021

Responses Of Pacific Fishers To Habitat Changes As A Result Of Forestry Practices In Southwestern Oregon, Tessa R. Smith

All Graduate Theses and Dissertations

The fisher (Pekania pennanti) is a medium-sized carnivore found in mature forest stands across much of the northern United States. Although historically abundant in the west, fisher populations declined rapidly after fur trapping, extensive logging, and urban development reduced their numbers. Currently, biologists are concerned about the effects timber harvest practices have on fisher tolerance and adaptability when faced with changes to high-quality habitat stands. Tree removal and thinning of understory vegetation are frequently used to alleviate the spread of wildfires in previously dense forest stands with a potential for large-scale habitat loss; yet, a deficit of large trees and ...


Patterns Of Use In A Division I University Fueling Station Before And After Implementing A Nutrition Education Intervention, Cady L. Peters May 2021

Patterns Of Use In A Division I University Fueling Station Before And After Implementing A Nutrition Education Intervention, Cady L. Peters

All Graduate Theses and Dissertations

Well-timed nutrition strategies are a well-established way to improve athletic performance and minimize recovery time, however, athletes often do not prioritize nutrition as a strategy to gain an edge over their competitors. Even with a resource such as a Fueling Station, which provides athletes with nutrient dense, convenient pre- and post-workout snacks, athletes still struggle understanding which foods are an appropriate choice for their purpose of eating.

The purpose of this research was to examine the changes in the appropriateness of the athlete’s meal choices at the Fueling Station based on their macronutrient distribution and timing of workout or ...


The Effects Of Trace Mineral Supplementation On Performance, Health, And Carcass Quality Of At-Risk Mineral Deficient Feedlot Cattle, Tevan J. Brady May 2021

The Effects Of Trace Mineral Supplementation On Performance, Health, And Carcass Quality Of At-Risk Mineral Deficient Feedlot Cattle, Tevan J. Brady

All Graduate Theses and Dissertations

Morbidity in feedlot cattle due to disease is a common economical loss for feedlot producers. Utah is not typically considered a ‘feedlot state’, but there are several producers in the southern part of the state that specialize in receiving at-risk cattle. These cattle are at-risk because they are coming from areas known to be mineral deficient. Areas such as the western US, are known to be deficient in several trace minerals important in immune response. Therefore, it is critical that producers have an adequate plan to decrease the negative effects that this has on economic viability of their beef operations ...


Range-Wide Migratory Connectivity Of Painted Buntings, Andrew J. Sharp May 2021

Range-Wide Migratory Connectivity Of Painted Buntings, Andrew J. Sharp

All Graduate Theses and Dissertations

The Painted Bunting (Passerina cirus) is a small (~16g), short/medium-distance migratory songbird that is listed as a species of conservation concern by the US Fish and Wildlife Service. Painted Buntings breed in two distinct populations, one eastern population and one interior population, separated by a 500 km gap that stretches from Mississippi to Georgia. I analyzed tracking data from 112 Painted Buntings from 11 different breeding sites to explore how individuals from different breeding sites differ in wintering location (chapter 2) and migratory timing (chapter 3). Additionally, I examined differences in migratory behavior between male and females in the ...


Patterns Of Post-Fire Aspen Seedling Establishment, Growth, And Mortality In The Western United States, Mark Regier Kreider May 2021

Patterns Of Post-Fire Aspen Seedling Establishment, Growth, And Mortality In The Western United States, Mark Regier Kreider

All Graduate Theses and Dissertations

Sexual seedling establishment in aspen is increasingly recognized as an important natural regeneration pathway for the species in the western U.S. However, information on seedling abundance as well as factors influencing aspen sexual regeneration is limited and frequently anecdotal, due to historical assumptions of seedling rarity as well as difficulty identifying sexual seedlings from asexual aspen sucker regeneration. This thesis contributes to the field of aspen seedling ecology in three major ways. Chapter 1 utilizes historical aspen seedling occurrences in the western U.S. and a systematic field survey of 2018 fire footprints to explore patterns and test assumptions ...


Investigation Of Methionine And Lysine Derivatives As A Source Of Rumen-Protected Amino Acids For Lactating Dairy Cows, Mark Avila Fagundes May 2021

Investigation Of Methionine And Lysine Derivatives As A Source Of Rumen-Protected Amino Acids For Lactating Dairy Cows, Mark Avila Fagundes

All Graduate Theses and Dissertations

Cows have a protein requirement for growth, maintenance, and lactation. In order to meet those protein requirements, dairy farmers can supplement or feed cattle with specific amino acids, the building blocks that make-up protein. However, in order for the amino acid product to be effective it must avoid degradation in the rumen and be delivered in the small intestine for absorption. Lysine and methionine have traditionally been recognized as the most limiting amino acids for lactating dairy cows. Therefore, nutrition companies have focused on finding ways to encapsulate or protect lysine and methionine from rumen microbes. The N-acetyl-L-methionine and N-acetyl-L-lysine ...


The Fate And Cycling Of Nitrogen, Phosphorous, And Trace Heavy Metals In Beaver-Altered Headwater Streams, Desneiges S. Murray May 2021

The Fate And Cycling Of Nitrogen, Phosphorous, And Trace Heavy Metals In Beaver-Altered Headwater Streams, Desneiges S. Murray

All Graduate Theses and Dissertations

Human land-use can increase the amount of non-point source (NPS) pollution in a stream, negatively affecting ecosystem health and beneficial services provided by an ecosystem. Unfortunately, NPS pollution remains high in many waterbodies. Beaver dams may be a passive, cost-effective strategy for removing NPS pollution in headwater streams because beaver dams slow stream flow and collect sediments. Impounded sediments can change how nutrients and pollutants are cycled in a stream through multiple pathways. In the first part of our study, we investigated whether beaver activity can reduce nitrogen, phosphorous and heavy metals from otherwise traveling downstream. Results suggest beaver ponds ...


Fatty Acid Composition Of Forages And Their Effect On The Fatty Acid Composition In Beef Cattle, Britney G. Allen May 2021

Fatty Acid Composition Of Forages And Their Effect On The Fatty Acid Composition In Beef Cattle, Britney G. Allen

All Graduate Theses and Dissertations

This study focused on how diet changes the rumen microbiome in the cattle and the effects of that on the long chain fatty acids (LCFA) by microbes in the rumen, and on the short chain fatty acids (SCFA) these microbes produce from feed carbohydrates like fiber and starch. The abundance of bacteria belonging to the phyla Tenericutes and Proteobacteria increased in response to high-fiber or high-starch diets, respectively. The production of two SCFA was positively correlated with the presence of increased Tenericutes (acetate) and Proteobacteria (propionate). A greater acetate to propionate ratio is associated with elevated production of enteric methane ...


An Eulerian Perspective On Spring Migration In Mule Deer, Tatum Del Bosco May 2021

An Eulerian Perspective On Spring Migration In Mule Deer, Tatum Del Bosco

All Graduate Theses and Dissertations

Many herbivores travel between low-elevation winter ranges and high-elevation summer sites. These seasonal movements allow them to avoid deep snow cover, ensure access to favorable habitat, and maximize food intake throughout the year. During the spring season, plants at lower elevations green up earlier at lower elevations than at higher elevations. It has been shown that individual animals will track this vegetation growth during their spring migration, which allows them to maximize forage intake coming out of the nutrient scarce winter. This phenomena has previously been studied by monitoring individual movement trajectories, but it is unknown how this pattern scales ...


Compost And Cover Crop Effects In Dryland Organic Wheat, Michael D. Deakin May 2021

Compost And Cover Crop Effects In Dryland Organic Wheat, Michael D. Deakin

All Graduate Theses and Dissertations

Producers of dryland organic wheat (Triticum aestivum L.) in the western USA struggle to maintain adequate soil fertility due to the high cost of organic fertilizers and concerns over moisture use of cover crops. Low soil fertility results in decreased wheat yield and quality, and increased year-to-year variability in yield and quality based on weather. This study was conducted to measure the effects of, and interactions between, cover crop mixes and a one-time compost application on soil health and winter wheat yield and quality. The study was located on three adjacent certified organic wheat farms near Snowville, UT, each with ...


Seeding Rate, Herbicide, And Irrigation Effects On Spring-Seeded Oat-Alfalfa Companion Crops, Carson D. Roberts May 2021

Seeding Rate, Herbicide, And Irrigation Effects On Spring-Seeded Oat-Alfalfa Companion Crops, Carson D. Roberts

All Graduate Theses and Dissertations

Small grain companion crop seeding rate recommendations for alfalfa (Medicago sativa L.) establishment are dated and inconsistent, and how a small grain companion crop seeding rates should be adjusted at different moisture levels is unknown. A study was conducted to provide clarity about oat (Avena sativa L.) companion crop seeding rates that maximize weed suppression and forage yield and minimize the effect on alfalfa stand establishment. This experiment considered oat companion crop seeding rates at various irrigation levels. Companion crop treatments consisted of oats sown at 89, 45, 22, 10, and 0 (with and without herbicide) kg ha-1. Irrigation ...


Mechanisms Of Overyielding And Coexistence In Diverse Tallgrass Prairie Communities, Leslie E. Forero May 2021

Mechanisms Of Overyielding And Coexistence In Diverse Tallgrass Prairie Communities, Leslie E. Forero

All Graduate Theses and Dissertations

Plants compete for the same basic nutrient and water resources. According to the competitive exclusion principle, when a substantial overlap in resource pools exists, the best competitor for resources should drive all other species to extinction. The ability for plants to coexist in violation of the competitive exclusion principle is the “biodiversity paradox”. Coexistence is actually beneficial for plants: as species diversity increases, you typically see increases in plant biomass production (known as the biodiversity-productivity relationship). The mechanisms behind coexistence and the biodiversity-productivity relationship remain an ecological mystery. One hypothesis is that plants obtain water and nutrients from different places ...


Bighorn Sheep Demographics Following Pneumonia Die-Off Events, Kylie Sinclair May 2021

Bighorn Sheep Demographics Following Pneumonia Die-Off Events, Kylie Sinclair

All Graduate Theses and Dissertations

Bighorn sheep populations across the Intermountain West are subject to disease pressure from the respiratory bacteria Mycoplasma ovipneumoniae. Although the effects of M. ovipneumoniae-associated disease die-offs are well documented, less is known about the factors driving long-term differences in post-die-off population responses. While many herds experience years to decades in which recruitment is less than 20 lambs per 100 ewes, some herds’ lamb survival rates are able to rebound rapidly following die-off events. The reason why these herds recover quickly while others do not is currently unknown. Here, we assess the roles environmental, demographic, and pathogen-associated factors could play ...


Greater Sage-Grouse And Community Responses To Strategies To Mitigate Environmental Resistance In An Anthropogenic Altered Sagebrush Landscape, Justin R. Small May 2021

Greater Sage-Grouse And Community Responses To Strategies To Mitigate Environmental Resistance In An Anthropogenic Altered Sagebrush Landscape, Justin R. Small

All Graduate Theses and Dissertations

Sagebrush (Artemisia spp.) ecosystems are diverse habitats found throughout western North America. Anthropogenic disturbances has resulted in the loss of over half of the sagebrush ecosystems impacting sagebrush obligate species such as sage-grouse (Centrocercus spp.). Federal, state, and private land managers have implemented landscape scale mechanical pinyon (Pinus spp.) and juniper (Juniperus spp.; conifer) removal projects in an effort to restore functioning sagebrush communities to benefit sage-grouse. However, few studies have investigated the potential for using large-scale conifer treatments to mitigate factors impeding sage-grouse seasonal movements and space-use in anthropogenic altered landscapes.

To address this management need, I analyzed pre- ...


Socioscientific Issues In School-Based Agricultural Education: Describing And Exploring Factors Of Integration, Michelle S. Burrows May 2021

Socioscientific Issues In School-Based Agricultural Education: Describing And Exploring Factors Of Integration, Michelle S. Burrows

All Graduate Theses and Dissertations

Socioscientific issues (SSI) are complex issues which are scientific in nature and have societal impacts. Many SSI have connections to agriculture and as such should be included in agricultural education curriculum. A clear understanding of what school-based agricultural education (SBAE) teachers know about SSI is needed. The purpose of this research was to explore the knowledge and integration of SSI among SBAE teachers by describing and explaining the factors that influence integration. This quantitative survey research was guided by the SSI-based instruction framework and the three-component model of agricultural education. The population for this study was all SBAE teachers in ...


Invasive Plant Occurrence Across Agency Boundaries: Two Case Studies From California, Natalie Otto May 2021

Invasive Plant Occurrence Across Agency Boundaries: Two Case Studies From California, Natalie Otto

All Graduate Theses and Dissertations

Non-native invasive species (NNIS) are a major concern confronting land managers in and surrounding protected areas such as national parks. These areas are managed by a variety of entities, all of which have different mandates, management priorities, and resources that are allocated to NNIS programs. These differences can result in ecological divergences at land boundaries and can create barriers to cooperative management. Through interviews and ecological data collection, this research addresses three topics; 1. It identifies disparities in NNIS and disturbance occurrence between jurisdictions and tests the strength of correlations between these variables; 2. It seeks to determine what role ...


Investigations Of Substrate Reduction By Nitrogenase: Light Powered Substrate Reduction By A Cds:Femoco System And Understanding Dinitrogen Inhibition Of Electron Transfer, Hayden Kallas May 2021

Investigations Of Substrate Reduction By Nitrogenase: Light Powered Substrate Reduction By A Cds:Femoco System And Understanding Dinitrogen Inhibition Of Electron Transfer, Hayden Kallas

All Graduate Theses and Dissertations

Nitrogen fixation is a key step of the nitrogen cycle which makes biologically inert N2 gas available for organisms to use in the form of ammonia. Nitrogen fixing microorganisms all contain the same enzyme called nitrogenase which catalyzes the six electron transfers to N2 required for conversion into ammonia. Nitrogenase is a two-component enzyme that contains a cofactor composed of iron and sulfur as well as heavier metals whose identity can be molybdenum, vanadium, or an additional iron atom depending on the variant. The two components of nitrogenase are the MFe protein and the Fe protein. The Fe ...


Visitor Perceptions And Resource Conditions Of Campsites In Two Coastal Alaskan National Parks, Shannon T. Wesstrom May 2021

Visitor Perceptions And Resource Conditions Of Campsites In Two Coastal Alaskan National Parks, Shannon T. Wesstrom

All Graduate Theses and Dissertations

Increasing visitation in parks and protected areas presents managers with the challenge of providing quality visitor experiences while mitigating ecological impacts from recreation. Successful management strategies often suggest determining desired conditions for visitor experiences and ecological conditions to establish thresholds. These thresholds can then be compared to existing conditions in order to determine if changes in management strategies should be made. By integrating visitor survey results with ecological assessments, this research is a unique coastal Alaskan regional analysis of the three components of a management framework: 1. Establishes visitor determined thresholds of acceptability for crowding and coastal resource conditions in ...


The Velvet Ants (Hymenoptera: Mutillidae): Systematics, Biology, And Biogeography Of A Little-Known Family, George Charles Waldren May 2021

The Velvet Ants (Hymenoptera: Mutillidae): Systematics, Biology, And Biogeography Of A Little-Known Family, George Charles Waldren

All Graduate Theses and Dissertations

Insects are a ubiquitous and species-rich component of the biologically-diverse planet we inhabit. The majority of insects are understudied, with many species awaiting formal description and their natural history yet to be discovered. Members of the family Mutillidae, commonly known as velvet ants, are one of these little-known insect groups. Velvet ants are technically wasps, and the wingless females superficially resemble true ants of the family Formicidae. Further, they frequently have a ‘velvety’ appearance and are often brightly colored to serve as a warning to would-be predators that they have the ability to inflict a painful sting. These insects are ...


The Consequences Of Environmental Properties And Tree Spatial Neighborhood On Post-Fire Structure Of Forest In Yosemite National Park, Jelveh Tamjidi Dec 2020

The Consequences Of Environmental Properties And Tree Spatial Neighborhood On Post-Fire Structure Of Forest In Yosemite National Park, Jelveh Tamjidi

All Graduate Theses and Dissertations

Separating the contribution of habitat filtering and dispersal mechanisms in forming species distribution remains a challenge in community ecology. Despite the effect of environmental variables in structuring communities, only restricted numbers of them were considered as a habitat dissimilarity.

In Chapter 2, I used topography and soil properties to define habitats within the Yosemite Forest Dynamics Plot (YFDP). The soil enzymes were added in soil samples due to their important role in releasing nutrients into the soil environment. The preference of eleven species to a specific habitat were examined. Also, the relative importance of habitat filtering and dispersal limitation were ...


Classification And Prediction Models For Natural Streamflow Regimes In The Arid Southwestern Usa, Angela M. Merritt Dec 2020

Classification And Prediction Models For Natural Streamflow Regimes In The Arid Southwestern Usa, Angela M. Merritt

All Graduate Theses and Dissertations

Understanding how natural variation in flow regimes influences stream ecosystem structure and function is critical to the development of effective stream management policies and actions. Spatial variation in flow regimes is well understood for stream reaches in mesic regions, but a more robust characterization of flow regimes in arid regions is needed, especially to support biological monitoring and assessment programs. Methods are specifically needed that can accurately predict the flow regime expected at ungauged reaches. We used long-term (41 y) records of mean daily flow from 287 stream reaches in the arid western USA to develop and compare several alternative ...


Assessing The Effects Of Cold Storage Regimes Of North American Bombus Queens: Long Live The Humble Queen, Thuy - Tien Thai Lindsay Dec 2020

Assessing The Effects Of Cold Storage Regimes Of North American Bombus Queens: Long Live The Humble Queen, Thuy - Tien Thai Lindsay

All Graduate Theses and Dissertations

Bumble bees (Bombus) provide critical pollination services for wild plants and crops. They are generalist pollinators, and do not depend on one singular floral type. Native bumble bees are adapted to pollinating many native plants, such as blueberries, squash, and tomatoes. A critical component of bumble bee pollination in the greenhouse tomato industry is the domestication of commercially bred colonies. However, the domestication of Bombus is pretty early in its development, and not all aspects of the bumble bee life cycle is fully understood. This thesis addresses one of the major obstacles in domestication, which is successful mimicking of the ...


Selection And Propagation Of Pinyon Pine, Kylie M. Lawson Dec 2020

Selection And Propagation Of Pinyon Pine, Kylie M. Lawson

All Graduate Theses and Dissertations

Single-leaf pinyon pines are drought tolerant trees native to the Great Basin. This species is a source of wild-collected, edible pine nuts that are in great demand. With no previous research apparent, this thesis aimed to identify wild trees with high cone production as sources for evaluating grafting onto immature and mature trees. Wild sources of scions were identified from four wild stands and six trees per stand. Counting and analyzing the number of scars left by mature cones along the leader branch provided an estimate for each tree’s productivity and identified trees with greater productivity within a stand ...


Effects Of Wi-Fi-Enabled Smart Irrigation Controllers On Water Use And Plant Health Of Residential Landscapes In The Intermountain West, Shane R. Evans Dec 2020

Effects Of Wi-Fi-Enabled Smart Irrigation Controllers On Water Use And Plant Health Of Residential Landscapes In The Intermountain West, Shane R. Evans

All Graduate Theses and Dissertations

Residential and commercial landscapes provide home and business owners with several benefits. These benefits range from improved air quality and flood control to the reduction of noise and breakdown of organic chemicals. However, these landscapes are routinely overwatered which can lead to plant disease, nutrient pollution, and large amounts of water being wasted. Utah State University, in conjunction with the Center for Water Efficient Landscaping (CWEL), the Utah Division of Natural Resources and Weber Basin Water Conservancy District, conducted an experiment to determine if Wi-Fi-enabled smart irrigation controllers conserve water as compared to average residential irrigation amounts and manually programmed ...


Effect Of Biocrust Development On Establishment Of Native Plants In A Salt Desert System, Merran Owen Dec 2020

Effect Of Biocrust Development On Establishment Of Native Plants In A Salt Desert System, Merran Owen

All Graduate Theses and Dissertations

Salt desert shrublands are semiarid, shrub-dominated ecosystems that inhabit salt- affected soils. In Great Basin salt deserts, exotic annual plants are invading and displacing native plants. Low plant productivity and slow population growth of native plants in these ecosystems makes them vulnerable to invasion and limits their ability to compete with invasive plants and return to a natural state. Active revegetation efforts, such as planting and direct seeding of native plants, are often unsuccessful for the same reasons. Biological soil crusts (communities of cyanobacteria, lichen, moss, microfungi and other microorganisms that live on the surface layer of the soil) are ...


Demographics, Accuracy, And Impact Of Feed Laboratories In The United States, Jerald H. Severe Dec 2020

Demographics, Accuracy, And Impact Of Feed Laboratories In The United States, Jerald H. Severe

All Graduate Theses and Dissertations

Feed analysis is very important to modern society. In the United States feed analysis is used to optimize production of food animals. Feed analysis is also used as a tool to place value on crops. As important as feed analysis is to society, little research has been done that describes which feed laboratories are the most popular and why people use them. It has been thought by some patrons that different results from the same feed sample are obtained by different laboratories. Is this true? If so, what is the effect on those that use feed laboratories to produce animals ...