Physical Sciences and Mathematics Commons^™

Reducing Reliance On Supplemental Winter Feeding In Elk (Cervus Canadensis): An Applied Management Experiment At Deseret Land And Livestock Ranch, Utah, Dax L. Mangus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife managers have fed elk in North America for nearly 100 years. Giving winter feed to elk can compensate for a shortage of natural winter range and may boost elk populations while also helping prevent commingling with livestock and depredation of winter feed intended for livestock. In contrast to these benefits of supplemental feeding, there are economic and environmental costs associated with feeding, and elk herds that winter on feeding grounds have a higher risk of contracting and transmitting disease. Brucellosis is of primary concern now, and Chronic Wasting Disease may be in the future. Many see the discontinuation of …

The Transfer Of Agricultural Water To Municipal And Industrial Usages, Dallin Paul Stephens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The water that is available for beneficial use in Utah is quickly approaching full appropriation; water that has been claimed is nearing the amount that is available for use. The Division of Water Resources of the State of Utah has organized a three-part plan to "Plan, Conserve, Develop and Protect Utah's Water Resources." One of these three elements has a focus to "provide comprehensive water planning." Such planning is best achieved when current and accurate data on the uses of the state's water are available.

The primary purpose of this thesis was to provide an evaluation, from data collected on …

Spatiotemporal Modeling Of Threats To Big Sagebrush Ecological Sites In Northern Utah, Alexander J. Hernandez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study tested the performance of classification, regression, and ordination techniques to evaluate the spatiotemporal dynamics of threats to big sagebrush ecological sites. The research was focused on invasion by annual exotic grasses and encroachment by woodlands.

We sought to identify those areas that have had a persistent coverage of cheatgrass (Bromus tectorum) in big sagebrush ecological sites. We took advantage of the contrast in greenness between multi-temporal (within one year) remotely sensed vegetation indices captured in the spring and summer to find a distinct phenological signature that allowed mapping cheatgrass. We utilized support vector machines (SVM) to classify three …

Individualistic Response Of Piñon And Juniper Tree Species Distributions To Climate Change In North America's Arid Interior West, Jacob R. Gibson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Piñon and juniper tree species have species-specific climatic requirements, resulting in unique distributions and differential responses to climate change. Piñons and junipers co-dominate the arid woodlands of North America as groups with widespread hybridization. Two piñons, Pinus edulis; P. monophylla, and four junipers, Juniperus deppeana var. deppeana; J. monosperma; J. occidentalis; J. osteosperma, are endemic to the midlatitude interior west and form three groups of hybridizing sister species, P. edulis-P. monophylla; J. deppeana var. deppeana-J. monosperma; J. occidentalis-J. osteosperma. Recent droughts have caused widespread mortality among piñons, but have had less impact on …

Invertebrate Community Changes Along Coqui Invasion Fronts In Hawaii, Ryan T. Choi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Puerto Rican coqui frog, Eleutherodactylus coqui, was introduced to Hawaii in the late 1980s via the commercial horticulture trade. Previous research has shown that coquis can change invertebrate communities, but these studies were conducted at small scales using controlled, manipulative experiments. The objective of this research was to determine whether coqui invasions change invertebrate communities at the landscape scale across the island of Hawaii. At each invasion front, we measured environmental variability on either side of the front and removed sites that were too variable across the front to ensure that the impacts we measured were the result …

Factors Affecting Greater Sage-Grouse (Centrocercus Urophasianus) Survival And Movement In South-Central Utah, Danny Caudill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse are the largest North American grouse species and are dependent on sagebrush for survival. Sage-grouse populations have declined throughout the west. Habitat fragmentation and degradation are likely the main causes of declining populations, and concern has lead to the petitioning for the sage-grouse to be listed under the Endangered Species Act. Survival of adult and juvenile sage-grouse is thought to be limiting population growth. However, survival of juvenile sage-grouse is poorly understood. I aimed to improve the knowledge gap regarding juvenile sage-grouse survival. With improved knowledge of juvenile survival, management actions can be employed to benefit sage-grouse populations. …

Process-Based Management Of Downy Brome In Salt Desert Shrublands: Assessing Pre- And Post- Rehabilitation Soil And Vegetation Attributes, Merilynn Carol Hirsch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As an ecosystem driver, downy brome (Bromus tectorum L.) presents obstacles to land rehabilitation efforts, including restoring desirable species cover. Because damaged ecosystems may have crossed both abiotic and biotic thresholds, ecologically-based control strategies may assist with altering successional trajectories and restoring desirable plant species. My thesis research had three objectives: 1) assess soil and vegetation relationships in degraded salt desert ecosystems prior to implementing downy brome control treatments, 2) determine the effects of control treatments on soil properties and resident plant species, and 3) evaluate the relative importance of shrubland soil type, herbicide type, and herbicide rate on seedling …