Life Sciences Commons^™

Warming Of The Southern Ocean During The Paleocene-Eocene Thermal Maximum: Inferences From Foraminifera At Site U1580, Samina Anee

All Graduate Reports and Creative Projects, Fall 2023 to Present

The Paleocene-Eocene Thermal Maximum (PETM, ~56 million years ago) represents an ancient episode of rapid global warming, offering critical insights into climate dynamics and the Earth's response to increased greenhouse gases. This project aims to quantify the magnitude of warming across the PETM at newly recovered IODP Site U1580 (Agulhas Plateau, Southern Ocean) through the analysis of Mg/Ca and δ¹⁸O ratios of planktic foraminifera. Understanding the extent of warming at Site U1580 is crucial for comprehending past climate variability and improving future climate predictions. Site U1580 is particularly well-suited to foraminiferal geochemistry because of high carbonate content throughout …

Groundwater-Dependent Ecosystems In Southeastern Utah: An Integrated Analysis Of Hydrology, Ecology, And Landscape Change, Colten Lay

All Graduate Reports and Creative Projects, Fall 2023 to Present

In Southeastern Utah, springs play a critical role in sustaining groundwater-dependent ecosystems (GDEs) in a semi-arid environment. However, they remain understudied and face growing threats from climate change, land use modifications, and hydrologic alterations. This study addresses knowledge gaps in spring occurrence, hydrologic function, and ecological condition by integrating field surveys, remote sensing, and geospatial analysis across multiple spatial scales. It provides a comprehensive assessment of spring hydrology, water quality, and ecological conditions using field surveys, remote sensing, and GIS analysis to establish a foundational baseline of GDE resources in the region. I applied a multi-scale monitoring approach across the …

Validation Of Head Above And Head Submerged Hydrostatic Weighing Equations And Air Displacement Plethysmography, Axel M. Miller

All Graduate Reports and Creative Projects, Fall 2023 to Present

Traditional hydrostatic weighing (HW) involves full body submersion at residual volume (RV), which may be uncomfortable. Thus, the purpose of this study was to investigate a more comfortable way to perform this method. HW with the head above water (HW_HAW) was compared to the traditional method of HW with head below water (HW_HBW) and to another method that also measures density by displacement, air displacement plethysmography (ADP). Equivalence was tested by comparing the body fat percentage (BF%), body volume (Vb), and body density (Db) of 27 subjects (15 M, 12 F) between the three methods. Results …

Intra-Stand Movement Of Balsam Woolly Adelgid (Adelges Piceae) In The Intermountain West, Michael S. Wayman

All Graduate Theses and Dissertations, Fall 2023 to Present

Balsam woolly adelgid (BWA, Adelges piceae (Ratz.)) is an invasive insect of true firs (Abies spp.). BWA has spread from initial introductions on the west coast of North America in the 1920s through the Intermountain West and has recently invaded Utah. White fir (A. concolor) and subalpine fir (A. lasiocarpa) are the two main species of concern in this region; however, subalpine fir has been found to be more susceptible to attack and subsequent damage. While long-range dispersal mechanisms and patterns are of interest for spread across regions and for predicting new infestations, very little …

Optimizing Delphinium And Larkspur Through Timing And Protective Cultivation Methods For Cut Flower Production, Nicholas Kirwan Volesky

All Graduate Theses and Dissertations, Fall 2023 to Present

Cut flowers have become an increasingly important specialty crop for small farms nationwide, and particularly in Utah, where decreasing agricultural land has heightened the need for profitable cropping options. However, production is challenged by Utah’s high-elevation climate, which presents unique constraints not addressed by current recommendations. Cool-season crops, like delphinium (Delphinium spp.) and larkspur (Consolida ajacis L.), are underproduced yet highly marketable, generating strong interest among growers throughout the state. Developing region-specific production guidelines is essential to help optimize yields, extend harvest windows, and meet local demand. This research evaluated spring planting dates in high tunnel and field …

Habitat Selection Analysis Of Mule Deer To Determine Efficacy Of The Coyote Bounty Program In Utah, Xaela M. Walden

All Graduate Theses and Dissertations, Fall 2023 to Present

Mule deer populations have been declining over the past couple of decades in many parts of the western United States. Often times, predators are blamed for the decreases in deer populations. Because of this, wildlife managers implement programs focused on reducing the number of predators on the landscape in an attempt to increase deer populations. However, predator removal programs have had mixed results, thus further investigation is needed to determine if coyote removals by the public through a bounty program have a positive effect on mule deer populations. My study investigated whether coyote removals through the bounty program in Utah …

Morphological Correlates Of Limaxivory In Contia (Serpentes: Dipsadinae) Compared To Related Taxa Carphophis And Diadophis, Lauren A. Houstoun

All Graduate Theses and Dissertations, Fall 2023 to Present

Differences in the skull and musculature of snakes can often be linked to their diet. Snakes that eat snails and slugs have evolved independently at least four times. Several skull features of the skull have already been reported in snakes that eat snails, specifically those in the genus Pareas and some Dipsadini. Among those features are a shorter, more compressed snout and, in some species, asymmetry of the lower jaw. However, little attention has been paid to snakes that specialize only on slugs (limaxivores). Unlike the snail-eating members of the Pareidae and Dipsadini, limaxivores lack the morphological traits associated with …

Cutting Propagation And Out-Planting Of White-Margined Beardtongue (Penstemon Albomarginatus M.E. Jones), A Vulnerable Herbaceous Perennial Of The Mojave Desert), Alexander Stosich

All Graduate Theses and Dissertations, Fall 2023 to Present

Plant biodiversity is crucial for the proper functioning of ecosystems, with many species needed to maintain the variety of functions provided, especially with increasing environmental change. However, plant biodiversity is threatened in many different ecosystems, primarily through habitat loss. Species can be conserved by protecting their original habitat and mitigating for threats such as invasive species or altered disturbance regimes (plant conservation); however, with declining population numbers and continued habitat loss and/or disturbance, it may be necessary to actively move plants (plant restoration). Plant restoration is dependent on developing the capacity to a) reliably propagate plants in a nursery and …

Effects Of Elevation, Fire Age, Burn Severity, And Pre-Fire Vegetation On Post-Fire Sagebrush Songbird Communities, William D. Harrod

All Graduate Theses and Dissertations, Fall 2023 to Present

The Sagebrush Biome of western North America has been threatened by a combination of interconnected threats. In the Great and Columbian Basins, a large portion of sagebrush loss has been due to an increase in higher-severity wildfires, caused by invasive annual grasses. As sagebrush declines, numerous wildlife species that rely on the biome have experienced similar trends. Sagebrush-adapted songbirds such as sage thrasher, Brewer's sparrow, and sagebrush sparrow as well as steppe-songbirds, have all experienced population declines. Currently, limited information exists as to how fire severity or recovery affect these songbirds or what resource managers can do to improve their …

Linking Variation In Mule Deer Nutritional Condition And Age To Population Performance In A Temperate Environment, Kent R. Hersey

All Graduate Theses and Dissertations, Fall 2023 to Present

The amount of body fat animals have as they enter and exit winter can have major impacts on how well they survive and reproduce. Mule deer are widely distributed herbivores whose survival and reproduction are strongly tied to weather patterns and the quality of vegetation they consume, which in turn impacts nutritional condition. The objective of this study was to identify and quantify the factors (animal specific, climatic, or habitat) influencing mule deer body fat during both summer and winter in Utah and examine how nutritional condition influences survival. We found December body fat was most affected by December lactation …

Impacts Of 4r Nitrogen Management And Water Optimization On Soil Health, Kamaldeep Kamaldeep

All Graduate Theses and Dissertations, Fall 2023 to Present

Farmers in Utah and Idaho are facing growing challenges due to high fertilizer costs, limited irrigation water, and pressure to improve long-term soil health. To better understand current practices and grower attitudes, a survey was conducted in 2020 targeting 5,000 producers of small grains, corn, and potatoes. Although the response rate was low, 146 growers representing over 25,000 hectares of cropland participated. Survey results showed that most growers are open to improving nitrogen and irrigation practices and care about their soil health, even if not all are fully using 4R or precision agriculture methods.

This thesis includes two field studies …

Temperature Effects On Fruit Doubling And Bloom Prediction In Tart Cherry, Josette M. Moon

All Graduate Theses and Dissertations, Fall 2023 to Present

Tart cherry (Prunus cerasus) is a key horticultural crop in Utah. Extreme summer heat and cold weather in late spring are challenges to tart cherry production causing economic losses. These problematic weather conditions are influenced by the local landscape and are exacerbated by changing climate. This research explores (1) the impact of summer heat stress on fruit deformities, and (2) the accuracy of temperature-based predictions of spring bud development. High temperatures and water stress after harvest are known to cause a deformity known as twin or double fruits, resulting in unmarketable fruit. This disorder has been studied in …

Systematics, Evolution, And Species Delimitation Of Ichneumonidae (Hymenoptera) Based On Ultraconserved Element Phylogenomics, Brandon Ross Claridge

All Graduate Theses and Dissertations, Fall 2023 to Present

The diversity of life on Earth is highly skewed towards a few key groups of organisms. Parasitoid wasps are among the most species-rich yet understudied organisms on our planet. Ichneumonidae, the largest parasitoid wasp family, includes 25,000 known species out of an estimated total of 100,000, far exceeding the nearly 70,000 species of vertebrates. As parasitoids, ichneumonids lay a single egg onto or inside their hosts, and the resulting ichneumonid larva consumes its host, ultimately killing it. Most hosts are the larvae or pupae of moths, butterflies, flies, beetles, and other wasps, including many pest species injurious to agriculture and …

The Effects Of Temperature And Cardiotonic Steroids On Cardiac Function And Metabolism In Snakes, Hannah Wilson

All Graduate Theses and Dissertations, Fall 2023 to Present

The function of the heart provides a window into the physiology of vertebrates and a means of evaluating their response to the stresses imposed by diverse activities. I developed a miniaturized instrument to record electrocardiograms (ECGs), using open-source Arduino technology, that a snake can wear as a backpack. The backpack can also be used when the snake is in a metabolic chamber, to record the metabolic rate and ECG simultaneously. I first used the ECG backpack to record the physiology of snakes under different temperature conditions, to verify that the system worked as expected. the backpack was then used on …

Improving Seasonal Precipitation Forecasts In The Western United States Through Statistical Downscaling, Bradley Vernon

All Graduate Theses and Dissertations, Fall 2023 to Present

Seasonal precipitation forecasts are essential tools for water management, especially in drought-prone areas like the Western United States. While global forecasting systems can predict precipitation months to years in advance, these forecasts are typically produced at a coarse spatial resolution due to high computational costs – especially when multiple forecast iterations, or ensemble members, are included. This coarse resolution limits their ability to capture localized weather features, such as those shaped by the complex terrain of the Intermountain West. Here, analog statistical downscaling is demonstrated as an effective approach to enhance the spatial resolution of operational seasonal forecasts provided by …

From Rifles To Running Shoes: How Outdoor Recreation Trends Are Reshaping Conservation Efforts, Lane James Arthur

All Graduate Theses and Dissertations, Fall 2023 to Present

Parks and protected areas (PPAs) serve a dual purpose: they conserve wildlife and natural habitats while providing spaces for people to enjoy outdoor recreation. However, balancing conservation with recreation can be challenging, especially as outdoor activities continue to grow and evolve. In Utah, Wildlife Management Areas (WMAs) are set aside to protect important wildlife habitats and provide opportunities for hunting and fishing. Recently, these areas have seen an increase in activities such as mountain biking, trail running, and dog walking, some of which take place in areas which prohibit recreational activity in effort to protect wildlife. These shifts in recreation …

Early And Late Season Weed Control In Dormant Alfalfa, Mckenna Saige Barney

All Graduate Theses and Dissertations, Fall 2023 to Present

Hexazinone + diuron is an herbicide mix commonly used to control weeds in established alfalfa in the late fall or early spring when alfalfa is dormant. If applied outside full dormancy, this mix can cause significant crop injury. The Intermountain West’s cold weather leaves a narrow time frame for applicators to apply herbicide. To help extend the application period to when alfalfa has not yet entered complete dormancy, the burndown herbicide paraquat can be added to the tank mix. Paraquat burns back existing plant matter to prevent hexazinone + diuron from spreading throughout the plant and causing long-term crop injury. …

Remote Detection Of Pest Damage And Tree Health In Tart Cherry, Christina Klara Lilligren

All Graduate Theses and Dissertations, Fall 2023 to Present

With the increasing affordability of technology, using technological advancements to assess tree health might soon become a possibility in low input crops such as tart cherry. We evaluated the ability of drone-mounted multispectral cameras, ceptometry

(canopy density), and soil conductivity meters (soil texture) to predict pest occurrence and remotely detect tree health. Pest scouting data were compared to the different technological datasets to identify the possibility of use for pest detection. While drone-mounted multispectral cameras were able to identify chlorotic trees, powdery mildew was not reliably detectable under a management threshold with current multispectral camera technology. Trees with low canopy …

Assessing Long-Term Changes In Aspen Forest Cover In Northern Yellowstone National Park Before And After Carnivore Recovery, Nicholas J. Bergeron

All Graduate Theses and Dissertations, Fall 2023 to Present

The recovery of large carnivores (wolves, bears, cougars) in Yellowstone National Park and the subsequent decline of the area's elk herd have raised key questions about ecosystem restoration—particularly for species such as aspen, which are heavily browsed by elk. Following wolf reintroduction in the mid-1990s, scientists began tracking changes in browsing intensity and height of young aspen within sampling plots, assuming reduced browsing and taller stems were signs of population recovery. However, no studies have measured whether the total area covered by aspen stands actually increased, as would be expected with broader recovery. Moreover, the potential influence of climate change …

Ecology And Management Of Forest Grouse: Breeding Acoustic Monitoring, Spatial Behavior, And Harvest, Logan Clark

All Graduate Theses and Dissertations, Fall 2023 to Present

Forest grouse are difficult to study and manage in the Intermountain West because they live in remote, rugged areas and do not gather at predictable display sites like other grouse species. From 2023 to 2025, I studied two species, dusky grouse (Dendragapus obscurus) and ruffed grouse (Bonasa umbellus), to test new survey tools, track their seasonal movements, and evaluate hunting impacts.

First, I tested whether small audio recording devices placed in the forest could minimize labor needed for spring breeding surveys. To do this, I conducted traditional surveys with human observers at the same time and …

Exploring Biotic And Abiotic Drivers Of Ecosystem Properties: The Influence Of Waterbirds And Photodegradation On Wetland Ecosystems, Lindsay Miller

All Graduate Theses and Dissertations, Fall 2023 to Present

Wetlands provide a wide range of valuable ecosystem services: these are benefits from the environment that support human well-being, such as water filtration, fish and bird habitat, and shoreline protection. Despite their importance, wetlands are among the most threatened ecosystems, facing increasing pressure from natural and human activities. To better predict the future of wetlands and guide effective management and restoration practices, we need to understand the various forces shaping their ecological properties. In this thesis, we examined the influence of two forces: waterbirds and photodegradation (the process by which sunlight breaks down plant material). To explore each of these …

Soil Health On Utah's Farms And Ranches, Jenae Dean

All Graduate Theses and Dissertations, Fall 2023 to Present

The term soil health has gained popularity in agriculture due to prolonged droughts, rising food costs, and the growing public concern for sustainable and organic practices. Soil health practices can offer solutions to all of these pressures. This thesis provides Utah's farmers and ranchers with quantifiable data on implementing soil health practices in Utah's unique climate. It presents the first two years of on-farm trial results on yield and quality after implementing various soil health practices on five categories of crops: corn, mixed hay, alfalfa, produce, and dryland grain. Over a two-year period, none of the soil health practices resulted …

Understanding Hydroclimate In The Contiguous United States: Roles Of Temperature Vs Precipitation And Subtropical Pacific Warming, Grace Esenam Affram

All Graduate Theses and Dissertations, Fall 2023 to Present

This study investigates the physical drivers and mechanisms of hydroclimate variability across the Contiguous United States (U.S.), using a combination of observable data, reanalysis data, land modeling, and coupled climate model experiments. One of the major findings is that the historic 2021 drought event across the Western U.S. was primarily driven by a severe lack of precipitation rather than increased temperatures. The study further finds that anthropogenic forcing has substantially increased the risk of this extreme drought by approximately 26 times relative to a world without the influence.

Additionally, the study reveals that the Pacific Meridional Mode (PMM) characterized by …

The Pharmacology Of Gpr171 Ligands In The Treatment Of Pain: An In Vitro And In Vivo Preclinical Characterization, Max V. Mcdermott

All Graduate Theses and Dissertations, Fall 2023 to Present

Opioids are addictive, ineffective for long-term treatment, readily produce withdrawal and tolerance, and can cause overdose and death. These properties have contributed to an epidemic of addiction and overdose, which continues unabated in the United States. Therefore, new drugs to treat acute and chronic pain are needed. Opioids bind to receptors belonging to a superfamily of proteins called G protein-coupled receptors (GPCRs). GPCRs are the most commonly targeted proteins among FDA-approved drugs. As such, under-researched GPCRs are a viable source of new targets in the field of drug development. One such underexplored GPCR is GPR171. Studies have demonstrated that a …

Supplementing Tannins To Increase Performance And Reduce Methane Emissions In Cows Grazing On Western Grasslands, Horacio Pedro Blanchard

All Graduate Theses and Dissertations, Fall 2023 to Present

Cattle grazing on U.S. rangelands often rely on a limited diet made up mostly of grasses. As the seasons change from spring to fall, the nutritional quality of these grasses declines, leading to less efficient digestion and higher production of methane—a potent greenhouse gas. In addition, most grass-based pastures lack beneficial plant compounds, such as tannins.

This study explored whether adding natural tannins—specifically, condensed and hydrolyzable tannins from quebracho and chestnut trees—to the diet of grazing cattle could improve how the use efficiency of nutrients and reducing methane emissions from cattle. Over two years, 24 cow-calf pairs grazed in small …

Modeling For Functional Traits In Bluebunch Wheatgrass Using Unmanned Aerial Vehicle (Uav) High-Throughput Phenotyping, Brittany L. Johnson

All Graduate Theses and Dissertations, Fall 2023 to Present

Changing climates and shifts in community composition in the Intermountain West threaten sagebrush-steppe ecosystems, impacting both plants and animals. Restoring native grasses like bluebunch wheatgrass (Pseudoroegneria spicata; BBWG) can help ecosystems resist invasive species and recover from stress and disturbances. As a native cool-season grass, BBWG is widely used in rangeland restoration for the western U.S. Breeding programs for restoration plant materials, such as seeds for ecological projects, often require years or decades of field testing while facing staffing constraints. High- throughput phenotyping (HTP), which rapidly measures observable plant traits, offers a faster solution using drones to capture time-series …

Optimization Of The Root Zone In Controlled Environment Agriculture, Brendan Fatzinger

All Graduate Theses and Dissertations, Fall 2023 to Present

Controlled environment agriculture (CEA) helps grow plants in spaces where resources like water and nutrients are limited, such as deserts or spacecraft. Effective management of water in the root zone, the area where plant roots grow, is vital to keeping plants healthy, especially in closed-loop systems where water cannot be wasted, as will be necessary for long-duration space missions.

An improved automated watering system designed for use in space-like environments was developed over several trials. Early designs using suction to draw water through tubes faced problems with uneven watering and roots blocking the tubes. Switching to a system that pushed …

Evaluating Maternal Polar Bear Denning Habitat Along The Arctic Coastal Plain And Assessing The Potential For Noise Disturbance In Polar Bear Dens, Ethan Ducharme

All Graduate Theses and Dissertations, Fall 2023 to Present

Polar bears (Ursus Maritimus) in northern Alaska are increasingly choosing land instead of sea ice to build their maternity dens. As sea ice continues to decline due to climate change, this shift makes it more important than ever to identify and protect the areas where polar bears dig dens to give birth and raise their cubs. In the first part of my research, I used new satellite-based elevation data to map potential polar bear denning habitat across a large section of Alaska’s Arctic Coastal Plain. This technology allowed me to identify the types of sloped terrain where drifting …

Water Conservation Strategies For Growing Ornamental Plants In Utah Landscapes, Jenny L. Koller

All Graduate Theses and Dissertations, Fall 2023 to Present

When early pioneers settled in Utah, they faced challenges living in a dry region with limited water. They built dams, canals, and irrigation systems by working together as a community to manage their water needs. However, adoption of European landscaping methods, farming and rapidly growing population increased water need while climate change and frequent drought reduced water supply.

Today, Utah is one of the driest states and uses more water per person than most other states in the nation. If things don't change, the state could run out of water by 2060. To address Utah's growing water challenges, this research …

Evaluation Of Novel Biomarkers As Predictive Measures Of Mastitis – Establishing A Relationship With Health Status, Lamb Performance, And Determination Of Prevalence Of Mastitis In Ewes Under Intensive Management, Courtney Berghoff

All Graduate Theses and Dissertations, Fall 2023 to Present

Inflammation of the mammary gland, also known as mastitis, is a prevalent and financially impactful disease in sheep production. The objectives of this survey were to 1) evaluate current testing methods: somatic cell count (SCC), California Mastitis Test (CMT), and bacterial culture, as well as novel biomarkers: lamb performance, milk composition, and udder conformation, for their impact on ewes categorized as clinically healthy or unhealthy under intensive management systems at 15 days in milk (DIM) and 30 DIM, and 2) identify biological markers that are correlated with clinical and subclinical mastitis. Milk, blood, and fecal samples, a visual and physical …