Life Sciences Commons^™

Ecology And Management Of Dyer's Woad (Isatis Tinctoria) In Northern Utah, Erin Marie Hettinger

All Graduate Theses and Dissertations, Fall 2023 to Present

Dyer’s woad (Isatis tinctoria L.) is a non-native forb that continues to threaten natural areas throughout Northern Utah and much of the Intermountain West. Once introduced, dyer’s woad can become extremely invasive, decreasing forage quality, and displacing native species. While dyer’s woad is found throughout much of Northern Utah, its range in other states remains limited. If promptly managed, control success in these areas will be much higher and populations may be kept at bay before ecological damage becomes severe.

This project tested the ability of dyer’s woad seedlings to compete with common rangeland grasslands at varied densities as …

Opening The Black Box: Soil Microbial Communities In Field-Based Plant-Soil Feedback Experiments, Julia Kate Aaronson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plant-soil feedback is a process through which plants modify the properties of their associated soils, affecting their growth. PSF can play a key role in regulating plant growth and communities including altering plant invasion, rarity, and abundance. However, our understanding of the soil organisms that drive these plant growth responses is limited. Most studies treat soils as a ‘black box’ and do little to reveal which specific microbes or microbial communities may be responsible. This chapter examines two recent large PSF field experiments conducted in Minnesota, USA, and Jena, Germany. These experiments revealed that plants altered their soils, changing subsequent …

A Mechanistic Examination Of Interspecific Competition Between Wild And Domestic Herbivores, Courtney Check

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Large herbivores, such as mule deer and cattle have similar life histories and likely compete for resources. However, quantifying the extent to which these species compete and the specific resources they compete for has proved challenging. My research examines if cattle influence deer abundance and behavior due to competition for forage, competition for shade, and/or by affecting the predation risk of deer. Using a grid of autonomous trail cameras, I was able to determine if cattle abundance influences local deer abundance in relation to specific resources and habitat features. Using GPS data from collared deer, I was also able to …

A Statewide Evaluation Of Fuel Treatment Effectiveness In Altering Wildfire Outcomes On Public Lands In Utah, Jamela Charmaine Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fuel treatments are land management activities that reduce living and dead flammable materials on the landscape to mitigate undesirable wildfire behavior and effects. Common treatments in the western United States include mechanical methods such as thinning and mastication, prescribed burns, and chemical methods, such as herbicide application. Treatments usually have multiple objectives, including reducing fire intensity, protecting natural and cultural resources, slowing or disrupting a potential future fire’s path, supporting ecosystem health, and reestablishing low to mid severity fire cycles in ecosystems. Although treatments can potentially modify fire behavior and ecological health, they generally cannot prevent fires from igniting, eliminate …

Overcoming Barriers To Aquatic Plant Restoration: Addressing Gaps In Species Identification And Planting Techniques In The Intermountain West, Kate A. Sinnott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aquatic ecosystems provide many critical and economically valuable benefits, including drinking water, food, recreational opportunities, and water supply for irrigation and agriculture. However, the health of these systems has been severely impacted by human activities such as pollution, land conversion, and introductions of harmful species. Restoring native aquatic plants can help reverse this damage and reestablish benefits, though it is not a common practice. With an objective to increase capacity for aquatic plant restoration in the Intermountain West, I identified and addressed two major barriers: 1) a lack of confidence in aquatic species identification among wetland professionals, and 2) underdeveloped …

Practical Improvements For Pivot And Surface Irrigation, Jonathan A. Holt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Irrigation is critical to meeting global food and fiber demands. Optimizing agricultural irrigation may help sustain production levels, while reducing its demand for water. This research evaluated precision sprinklers and drip irrigation for pivots, five pivot track mitigation tools, three scientific irrigation scheduling (SIS) methods, sensors for surface irrigation cutoff, and automating surface systems to implement surge irrigation. With pivots and surface irrigation being the most common methods for irrigation in the West, small improvements from these tools could result in significant water savings.

Low energy precision application (LEPA) sprinklers and mobile drip irrigation (MDI) were tested on two pivots. …

Regeneration Of Quaking Aspen And Understory Vegetation Change After Fire Risk Reduction Treatment, Allison M. Trudgeon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaking aspen (Populus tremuloides Michx.) is a keystone species that, when coexisting with conifers (i.e., seral aspen), often undergoes stand-replacing disturbances to sustain long term vigor. Historically, mixed-to-high severity fire reduced fuels and regenerated aspen, but such disturbances have become less common in recent decades. This has often led to high fuel loading, and many seral aspen stands are at now risk of an unpredictable, high-severity fire, posing a threat to development in the wildland-urban-interface. The lack of a commercial market for aspen, and the risk of conducting prescribed fire, means there are few alternate management options. This has …