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 …

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 …

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 …