Physical Sciences and Mathematics Commons^™

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 …

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 …

Influence Of Hydrologic History On Nitrogen Cycling In Lake Sediments, Emily Jainarain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water quality is declining in freshwater lakes around the world due to environmental change and anthropogenic activities that threaten the physical, ecological, and geochemical integrity of freshwater ecosystems. Excess N and P in lakes can cause eutrophication, a major driver of water quality impairment that leads to excessive algal growth, or harmful algal blooms (HABs), and poses risks to recreation, fisheries, and public drinking water. Water level fluctuations in lakes are expected to become more frequent and intense as climate change increases periods of drought and alters precipitation patterns, and fluctuations may stimulate biogeochemical reactions in littoral sediments that add …

Effects Of Soil Amendments On Water Quality And Hydrologic Properties In Low Impact Development Systems, Lily Wetterlin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Low impact development (LID) systems are practices that use natural elements, such as soils and vegetation, to absorb and filter stormwater to protect water quality and aquatic habitats. Many LID designs use native soils; however, urban soils typically have a limited potential for infiltrating and treating stormwater. Incorporation of soil amendments, such as compost and biochar, into LID soils can improve the physical properties of soil. However, soil amendments may increase or decrease pollutants in the water leaving the site. A comparison of the effects of different types and application rates of amendments on water quality is necessary to determine …

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 …

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 …

Comparing Commonly Used Aquatic Habitat Modeling Methods For Native Fishes, Eryn K. Turney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water resources are managed for a variety of human needs, including agriculture, industrial and municipal consumption, hydropower generation, and recreation. There has been a recent push to incorporate habitat needs of aquatic wildlife into water management models alongside these other uses, particularly as competition for limited water resources in a changing climate has reduced instream flow and contributed to declining native fish populations. Habitat models are used to estimate species distributions and differentiate between suitable and unsuitable habitat based on variables important to a given species, but are not usually incorporated into water management models. Because there are many ways …

Big Fish And More Of Them: Salmonid Habitat Availability, Quality, And Use Across Multiple Scales Within A River-Reservoir System, John S. Mclaren V

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Reservoirs and their associated rivers provide water for agricultural and municipal uses, ecological benefits for fish and wildlife, and associated recreational activity. However, in the Greater Yellowstone Ecosystem climate change and population growth are putting pressure on water quality and supply, potentially damaging the unique and economically important coldwater trout habitat that these systems support. In this study, the author investigates the impact of changing water quality and supply on trout habitat quality, quantity, and selection to assist conservation goals in the Henry’s Fork Watershed in eastern Idaho. The study found that higher availability of cold-water refuge habitat in Island …

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 …

Recreational Fishing Participation In Utah: Comparing Active And Non-Active Angler Constraint Perceptions With The Use Of License Purchase Data, Will Rempel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As a leisure activity, recreational fishing provides numerous social, physical, and psychological benefits to its participants. It can also provide socioeconomic opportunities to specific communities, and as an outdoor activity can create support for natural fisheries resources and public lands. License and equipment taxes are also important funding mechanisms for state wildlife managers. Though fishing participation as a percentage of the population has overall decreased in the last century, there is a recent increase in fishing participation. However, participation dynamics result in a shifting cycle of entries, departures, and re-entries to the sport. In an effort to maintain participation and …

Cross-Boundary Stewardship In Protected Area Centered Ecosystems: Perceptions Of Success And Characteristics Of Cooperative Engagement, Ryan D. Tarver

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The legal boundaries of protected areas, such as national parks are established and enforced by humans. Therefore, jurisdictional boundaries are ultimately have human meaning but not necessarily ecological relevance as natural phenomena such as watersheds and wildlife habitat often extend beyond a jurisdictional boundary. When considering the extent of natural system, we find that protected areas only make up part of a given ecosystem. The result is a large expanse of lands that fall under a various ownership types that include both publicly and privately designated tracts of land. This presents a management challenge when attempting to manage at the …

Opportunities And Challenges For Cooperative Extension Becoming A Major Actor In Climate Change Mitigation And Adaptation, Dakoeta R. Pinto

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Addressing climate change in the United States is an increasingly complex issue that requires social and technological changes throughout the country, which the Cooperative Extension System (Extension) can influence. Based at land-grant universities, their goals are to bring relevant science and innovation to the people of the United States. For a successful low-carbon transition, there are certain elements of society that must be influenced by innovators like Extension. Extension’s historical roots in agriculture prevail today with most of their programming focusing on this sector. However, there is a movement within Extension to expand their programmatic efforts to address more contemporary …

Getting The Dirt On Phosphorus Pollution In Mountain Lakes: Are Rising Soil Temperatures Contributing To Eutrophication In Mountain Watersheds?, Gordon O. Gianniny

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mountain watersheds provide a critical supply of clean water to millions of people around the world. In recent years, evidence of a concerning trend has emerged in these watersheds: rising phosphorus (P) concentrations. P often acts as the limiting nutrient in mountain lake ecosystems, so increasing P availability in mountain lakes and streams has the potential to drastically increase algal growth in these systems. In extreme cases, increasing mountain lake P concentrations may even cause harmful algal blooms that degrade downstream water quality. While the implications of rising P concentrations in mountain lakes are serious, the cause driving this widespread …

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. …

From Mountain Streams To Urban Rivers: An Assessment Of Microplastic Sources And Characteristics, Macy Gustavus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plastic products are produced and discarded at an alarming rate. Bottles, bags, toys, and clothing break down into tiny plastic pieces called microplastics, ranging in size from an eraser on the top of a pencil to smaller in size than a red blood cell. Microplastics are becoming so common in the environment that they travel in the atmosphere, rivers, and ocean currents in ways that are similar to other types of Earth Systems Cycles (i.e., the water cycle). In this study, we explored microplastic sources and sinks in a freshwater river system and how seasonal changes in discharge affect how …

Human Appropriation Of Net Primary Production Through Crops, Grazing, And Forestry In The U.S. From 1997 To 2012, Suman Paudel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation conducts a county-level analysis of human appropriation of net primary production (HANPP) harvested from crops, timber and grazing in the conterminous United States in the years 1997, 2002, 2007 and 2012. This study consists of three manuscripts (Chapters 2, 3, and 4). The first study quantifies net primary production in US counties in 1997, 2002, 2007 and 2012. The detailed HANPP study conducted concludes that HANPP is a valuable footprint tool for analyzing land use intensity and agricultural ecosystems. The second manuscript shows how HANPP is an improved or modernized ecological footprint and is a sustainable indicator as …

River Response To Sediment Supply: The Sand Bed Case, Christina M. Leonard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Effective management of in-channel and floodplain habitat requires an ability to forecast river response to changes in water and sediment supply. These changes may result from dam construction/decommissioning, changes in reservoir operations, or changes in grazing or forestry practices. If a change in water and sediment supply causes sediment to be delivered faster than the channel’s capacity to transport it, sediment will accumulate in the reach, leading to changes in channel form and increasing the potential for flooding. A decrease in sediment supply relative to transport capacity can lead to channel incision. The extent and timing of sediment accumulation or …

Old-Growth Forest Dynamics After Fire And Drought In The Sierra Nevada, California, Usa, Kendall M.L. Becker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding forest ecosystems is important because forests cover approximately one-third of Earth’s land area, store half of Earth’s carbon, shelter half of Earth’s species, and absorb a quarter of new anthropogenic carbon emissions, slowing climate change. This dissertation provides insight into future forest habitat, fuels, species composition, and structure by investigating what happens to snags, seedlings, and trees in an old-growth forest after a low- to moderate-severity fire.

Chapter II explores how low- to moderate-severity fire changes snag fall rates. Predicting how long snags will remain standing after fire is essential for managing habitat, understanding chemical cycling in forests, and …

Normative Evaluations Of Resource Conditions: The Influence Of Visitor Characteristics And Implications For Recreation Management In Urban-Proximate Parks, Jordan E. Nesbitt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Urban-proximate parks and protected areas provide a unique recreation landscape to individuals living in and near urban centers. They have been shown to provide similar recreation experiences to traditionally studied parks and protected areas such as National Parks, National Forests and Wilderness areas. This study takes place in a set of four urban-proximate parks in Orange County, California, USA. These parks are designated as urban-proximate because they are located within 100 miles of an urban center with 1 million or more people. Using norm theory, a well vetted social science theory, this work sought to identify thresholds of acceptability for …

Quantification Of Hydrologic Response To Forest Disturbance In Western U.S. Watersheds, Sara A. Goeking

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forested watersheds produce more than half of the water supply in the United States. Forests affect how precipitation is partitioned into available water versus evapotranspiration. This dissertation investigated how water yield and snowpack responded to forest disturbance following recent disturbances in western U.S. forests during the period 2000-2019.

Chapter 2 systematically reviewed 78 recent studies that examined how water yield or snowpack changed after forest disturbances. Water yield and snowpack often increased after disturbance, but decreased in some circumstances. Decreased water yield was most likely to occur following disturbances that did not remove the entire forest canopy. It was also …

A Dynamic Relationship With Wilderness: Comparing Day And Multi-Day Visitors' Indicators Of Quality In Wilderness Settings, Caleb Meyer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The length of stay in wilderness areas is declining and, in many areas, day visitors comprise most of all use. Most prior research exploring this trend took place in the 1990s and few studies of wilderness visitation account for the increase in outdoor recreation participation over the last decade. Lack of understanding surrounding this trend raises questions about managerial and philosophical approaches to the recreation-wilderness relationship. This study explored these topics within visitor use management approaches used by the National Park Service, which manages the proposed Glen Canyon Wilderness, near Escalante, Utah, where this research took place.

Results of this …

Comparing Fecal Dna Capture-Recapture Methods To Traditional Mark-Resight Methods For Estimating Abundance Of Mule Deer On Winter Ranges, Andi M. Stewart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Well-designed monitoring strategies are required to obtain accurate estimates of population abundance, which is important for evaluating conservation and management strategies. Obtaining abundance estimates using traditional survey methods, like aerial surveys, is not possible in all scenarios and can be expensive and risky. One survey method that has gained popularity in the last decade is fecal DNA-based capture-recapture (CMR). However, this method has not been evaluated on winter ranges or in snowy, winter conditions.

My first objective was to implement fecal DNA CMR to estimate abundance of mule deer in the Round Valley and Goodale winter survey areas in the …

Conservation Conflict: Rare Plant Conservation And Energy Development And Potential In The Colorado Plateau, Joshua Carrell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Colorado Plateau provides numerous sources of energy, particularly natural oil and gas. This energy potential is being actively extracted for consumption on both public and private lands. Elements of biodiversity (e.g., listed and sensitive plant and animal species) are distributed among all land tenures, yet the laws protecting them can vary depending if they occur on public, private, or tribal land. Therefore, it is necessary to understand the geographic ranges of threatened, endangered, and sensitive species and their relationship to land ownership to preserve habitat and conserve species populations. I developed species distribution models (SDMs) to examine the predicted …

The Effect Of Species Choice, Seed Mix Composition, And Microtopography On Native Plant Restoration In Great Salt Lake Wetlands, Coryna Hebert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wetlands are important ecosystems that improve water quality, prevent floods, and provide wildlife habitat. As such, restoring native plants that promote wetland health is a high priority for land managers. However, there are many challenges to the restoration of native plants. In our study system (Great Salt Lake wetlands), many areas are invaded by the European grass, Phragmites australis. Phragmites grows in dense stands and displaces native plants. The reduction of native plant communities in Great Salt Lake wetlands is a major concern because these ecosystems provide habitat for millions of native birds. Managers have made successful efforts to …

Investigating Factors That Impact Income Generation And Distribution In Western National Park Gateway Communities, Elizabeth Depew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many rural towns in the western united states have come to be defined by high levels of tourism, seasonal residents, and migration driven by the desire to be close to natural amenities and the higher quality of life they afford. This shift is especially apparent in communities that are “gateways” to natural amenities such as national parks. Embracing this shift towards the “New West,” many community planners have heralded amenity-led development as a remedy to the waning feasibility of relying on agriculture and extractive industries. However, anecdotal evidence and several case studies indicate the factors which make these gateway communities …

Conservation Genetics Of A Declining Bumble Bee In Western North America; The Influence Of Geography, Dispersal Limitation, And Anthopogenic Activity, Ashley T. Rohde

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Conservation biology addresses the problem of species loss by identifying species in need of protection. Conservation biology has subfields to address different aspects of biodiversity loss, including genetics and sociology. I used genetic approaches to assess the conservation status of western bumble bees, a bumble bee species of conservation concern.

The western bumble bee is a bumble bee species that ranges from Alaska to New Mexico and as far east as Wyoming and Colorado. This species is disappearing in some places. It may soon be listed as endangered in the United States and is already listed as endangered in parts …

A Multi-Scalar Socio-Policy Analysis Of Resource Reallocation And Water Security In Twenty-First Century Utah, Usa, Clint P. Carney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As drought and a warming climate continue to impact the western United States, balancing the water needs of cities, agriculture, and natural systems is becoming increasingly more complex. One approach commonly promoted to address water supply issues is the transfer of water between users via markets. However, markets for water face multiple obstacles that can often be costly for participants due to constraints inherent in western U.S. water law. Coinciding with issues of cost, water markets must overcome disinterest among water rights holders in releasing their water rights for uses even if temporarily. Moreover, water transfers bring to light the …

Characterizing Relational Values To Inform Message-Framing At The Boa Ogoi Historical Site, Cole G. Stocker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In an increasingly polarized political climate–particularly in the U.S.– environmental issues such as climate change and its effects on the environment have become hot-button partisan talking points resulting in further division. This has led to research on ways to communicate science which does not further inflame political tensions, but rather reinforces and validates the audience’s values. Science communication research provides the foundation for my case study, which focuses on characterizing the environmental values and worldviews of land managers residing and working near the Boa Ogoi Historical Site in southern Idaho. The Northwest Band of Shoshone Nation (NWBSN) is in the …

Valley Bottom Inundation Patterns In Beaver-Modified Streams: A Potential Proxy For Hydrologic Inefficiency, Karen Bartelt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For centuries river management and land use actions in North America have caused widespread stream degradation where water now flows downstream with artificially high efficiency. When present, beaver dams slow the flow of water and decrease the efficiency of water conveyance through the landscape. These effects are often to the benefit of the function of natural physical processes and ecology of the stream. The benefits provided by beaver dams have been well studied at small scales, but the methods that these studies rely on are often expensive and time consuming and consequently not feasible to deploy at larger spatial scales …

Predictive Models Of Post-Wildfire Debris Flow Volume And Grain Size Distribution In The Intermountain West, Sara Wall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Post-fire debris flows represent the most erosive and potentially hazardous consequence associated with increasing wildfire severity. While an abundance of research has explored where they are likely to occur and their potential magnitude, investigations into understanding how they impact downstream resources are limited. Recent advancements are seeking to link predictive models together to be able to predict how erosion after wildfire may impact reservoirs and aquatic habitat downstream. However, there are two key missing pieces into our ability to examine watershed-scale impacts of post-fire erosion. These include having accurate predictions of how much sediment is likely to be deposited by …