Environmental Sciences Commons^™

A Model Explaining Medusahead Invasion And Novel Targeted Grazing Approaches Of Control, Casey N. Spackman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Medusahead (Taeniatherum caput-medusae (L.) Nevski) is currently one of the biggest threats to rangelands and livestock operations in the Western US. High silica concentrations in medusahead contribute to its invasiveness. I developed a model to explain how silica is involved in the invasion process, and attempted to manipulate silica to increase use of the grass by livestock. Experiments were conducted to determine: 1) whether rotational grazing on established forages of improved nutritional quality would provide supplemental nutrients to increase cattle use of medusahead; 2) evaluate intake of and preference for medusahead treated with a glyphosate herbicide at different rates …

Why Do They Do That? Understanding Factors Influencing Visitor Spatial Behavior In Parks And Protected Areas, Abigail M. Sisneros-Kidd

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Visitors to parks and protected areas within the United States and worldwide often visit these areas with a particular destination in mind, such as seeing Old Faithful erupt in Yellowstone National Park or standing on the rim of the Grand Canyon in Grand Canyon National Park. These visitor use destinations, and the pathways leading to them, such as trails and roadways, see high levels of use, and as a result, impacts to soil, vegetation, air, water, soundscapes, and night skies that result from this use. The field of recreation ecology studies these impacts to park and protected area resources resulting …

Aligning Conservation Goals And Management Objectives For Bonneville Cutthroat Trout (Oncorhynchus Clarki Utah) In The Logan River, Utah, Harrison E. Mohn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rivers are often managed without informed knowledge of how sportfish use different areas of the river to reproduce, and rarely take into account the relationship between fish movement and how they are distributed within the river when making management decisions. The population of native Bonneville cutthroat trout (Oncorhynchus clarki utah) within the Logan River is the largest documented population remaining for this imperiled species, and still maintains extremely high numbers of fish in the upper river. Currently, fishing is not allowed in the upper 20 kilometers of the Logan River watershed during spawning, based on the assumption that …

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 …

Adoption Of Range Management Innovations By Utah Livestock Producers, Elizabeth Anne Didier

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent years have seen changes in ecological conditions, ownership patterns, and political-legal forces that affect the sustainability of Western range livestock production. Enterprise diversification and implementation of improvements are advocated as ways for ranchers to cope with marginal returns from ranching while better managing resources. However, relatively few ranchers make such substantive changes in their operations, and previous research suggests that rates of adoption may be especially low in Utah.

Using a qualitative approach, this study explored innovation adoption among Utah ranchers. During preliminary interviews with 13 key informants, commitment to traditional ranching lifestyles, the state's settlement pattern, and availability …

Natural Pastures Of The Macquarie Region Of New South Wales: Their Origin, Composition And Management, David Leslie Michaelk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two experiments were conducted in the semi-arid (400 millimeter annual rainfall) Macquarie region of New South Wales, Australia, at the Trangie Agricultural Research Station (31° 59'S; 147° S7'E), to examine (a) the way botanical parameters can be used to separate grazing and climatic impacts on range vegetation, and (b) how this delineation affects application of range science tenets (site, condition and trend) to different pasture types.

Two range sites were studied: Site 1, a light soil type, was dominated by annual grasses, legumes and forbs, whereas perennial grasses (mainly Chloris acieularis and Chloris truncata) dominated the heavy soils of …