Life Sciences Commons^™

The Role Of A Beaver In Shaping Stream Channel Complexity And Thermal Heterogeneity In A Central Oregon Stream, Florence Consolati Machen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

North American beaver (Castor canadensis) alter stream channel morphology, hydrologic processes, and instream temperature regimes, yet there are few data driven studies that investigate the effect of beaver on stream channel complexity and stream temperature regimes across multiple spatial and temporal scales. The use of beaver as a restoration tool is a method at the forefront of watershed restoration, however little is known about the implications of this restoration technique, particularly with regard to its ability to alter stream channel complexity and stream temperature. This thesis addresses two knowledge gaps with the following objectives: to quantify the role …

Control Of Large Stands Of Phragmites Australis In Great Salt Lake, Utah Wetlands, Chad R. Cranney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phragmites (common reed) is a non-native, invasive perennial grass from Eurasia that is taking over wetlands across North America. In Utah, Phragmites has expanded to cover tens of thousands of acres in and around the Great Salt Lake (GSL). The GSL and its associated wetlands are recognized regionally and hemispherically as an important bird area (IBA) that provide critical habitat for a wide variety of wetland dependent birds. The invasion and expansion of Phragmites has replaced many of the high quality habitats these avian populations rely on. This research aimed to determine the most effective methods to control Phragmites and …

Hybridization, Population Genetic Structure And Gene Expression In The Genus Boechera, Martin Peter Schilling

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When we look at life on earth, we can see a lot of different life forms, but we still do not fully understand how these different life forms came to be and at which points in time these life forms began to be different enough from each other so we could call them by different names, or species. Some groups of species on earth, especially plants, seem to reproduce with each other, even though they are already very different from each other so that we call them different species. This process is called hybridization, and it can stir up the …

Using Accelerometer Data To Remotely Assess Predation Activity Of Arctic Wolves, Heather Shipp

Undergraduate Honors Capstone Projects

Arctic wolves (Canis lupus arctos) play an important role in ecosystems located in the far northern regions of the world; however, unlike the gray wolves in Yellowstone National Park, little information is available about High Arctic wolves and their impacts on prey populations. This research uses data received from two GPS radio-collared Arctic wolves located in the Fosheim Peninsula on Ellesmere Island. Each radio-collar was programmed to record a position every 30-60 minutes, as well as the wolfs activity movement (forwards - backwards and left - right), which was generated by an accelerometer housed within the radio-collar. This …

Assessing Plant Community Structure In The Upper Las Vegas Wash Conservation Transfer Area, Nevada: The Influence Of Biotic And Abiotic Variables, Amy A. Croft

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecological communities are complex, the structure of which is composed of interactions between multiple community characteristics and the abiotic and biotic factors shaping them. Because of this complexity, ecological studies are generally limited in scope and size, often dissecting communities into their component parts to examine them piece by piece. While this might be the most practical method to study communities, this approach often neglects other characteristics that, with their inclusion, would provide a more complete picture of community ecology. The studies described in this dissertation were conducted in an effort to synthesize the complexity that is inherent in ecological …

The Demography And Determinants Of Population Growth In Utah Moose (Alces Alces Shirasi), Joel S. Ruprecht

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Moose (Alces alces) occur widely in northern regions of the world. Across their distribution, the species is considered to be of high intrinsic, ecological and recreational value. Populations of moose along their southern range limit in North America have shown erratic population dynamics in recent decades including severe numeric declines in some areas. Moose in Utah belong to the Shiras subspecies, which is a relatively understudied population segment. Additionally, moose in Utah represent the southernmost naturally occurring moose populations worldwide. Concerns over possible declines and a paucity of baseline data on moose within the state prompted the Utah …

A Spatiotemporal Mountain Pine Beetle Outbreak Model Predicting Severity, Cycle Period, And Invasion Speed, Jacob P. Duncan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mountain pine beetle (MPB, Dendroctonus ponderosae), a tree-killing bark beetle, has historically been part of the normal disturbance regime in lodgepole pine (Pinus contorta) forests. In recent years, warm winters and summers have allowed MPB populations to achieve synchronous emergence and successful attacks, resulting in widespread population outbreaks and resultant tree mortality across western North America. We develop an age-structured forest demographic model that incorporates temperature-dependent MPB infestations: the Susceptible-Infested-Juvenile (SIJ) model. Stability of equilibria is analyzed as a function of population growth rates, and indicates the existence of periodic outbreaks that intensify as growth rates …

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 …

Intraspecific Variation In The Response Of Elymus Elymoides To Competition From Bromus Tectorum, Rebecca K. Mann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the western United States, thousands of acres of degraded rangelands are dominated by aggressive invasive species such as cheatgrass (Bromus tectorum), and are seeded by managers with native plants in an attempt to restore species diversity, wildlife habitat, and ecosystem services. There are many options for obtaining seeds of native plants; for instance, they can be collected from the region where restoration is to occur, or they may be purchased through commercial producers. For a given plant species, managers may also select seeds from unique subspecies, cultivars, and populations. Genetic differentiation among these within-species groups can not only affect …

Rapid Savanna Response To Changing Precipitation Intensity, Ryan S. Berry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate change has the potential to cause large-scale changes in plant growth, biodiversity, and biosphere-climate feedbacks. A pervasive aspect of climate change is that as the atmosphere warms, precipitation events are likely to become less frequent but more intense, because warmer air can hold more water. Larger precipitation events can be expected to change plant productivity and community composition, particularly in semiarid ecosystems such as savannas. Savannas are of particular interest because they are spatially expansive at the global scale, they are important to humans for food production, and they are known to be sensitive to changes in soil water …

Refining Methods For Quantifying Macroinvertebrate Estimates Of Preference For Use In Stream Bioassessments, Ellen F. Wakeley Tomlinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two-thirds of United States stream length is in either fair or poor biological condition. However, we do not yet have reliable, quantitative tools to diagnose site-specific causes of biological impairment. One way to diagnose causes of impairment is to compare the environmental tolerances or preferences of the taxa expected at a site to those of the observed community. Stream ecologists have derived tolerance values (TVs) from field data for use in causal analysis, but inconsistencies across studies cast doubt on the accuracy of these TVs. Published TVs may not agree with one another for several reasons, including: differences in the …

Revegetation Of Bulrushes Bolboschoenus Maritimus, Schoenoplectus Acutus, And S. Americanus In Great Salt Lake Wetlands: Seed Biology And Influence Of Environmental Factors On Rhizomes, James Marty

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A primary goal of ecological restoration is to establish desirable plant species. This goal is particularly important following the removal of invasive plants. Understanding biological characteristics of plant species important to revegetation is crucial to plant establishment. In the globally important Great Salt Lake (GSL) wetlands, native habitat-forming bulrushes Bolboschoenus maritimus, Schoenoplectus acutus, and S. americanus are frequently displaced by the invasive grass Phragmites australis. Bulrush seeds require very specific germination conditions and are also dormant, therefore they do not germinate consistently even when exposed to appropriate germination conditions. Additionally, wetland environments are often associated with water …

Emerging Technology To Exclude Wildlife From Roads: Electrified Pavement And Deer Guards In Utah, Usa, Joseph P. Flower

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vehicle collisions with large wild animals threaten public safety, can harm wildlife populations, and often result in substantial property damage. The most effective
way to reduce these collisions is to install wildlife fencing along the roadway and provide structures that enable wildlife to cross roads safely. However, if access roads that bisect fencing do not include barriers to deter animals from entering the highway, these measures can become ineffective. The purpose of my research was to: 1) evaluate the effectiveness of barriers currently used to exclude wildlife from highways, and 2) determine whether cattle guards augmented with segments of electrified …

Does Experience With Sagebrush In Utero And Early In Life Influence The Use Of Sagebrush By Sheep?, Ashley T. Longmore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Learning from mother begins early in the developmental process and can have lifelong effects when it comes to forage preferences. Recent research suggests that mothers are a powerful and positive influence before birth. Pregnancy is not an incubation period buy a staging period for well-being and disease later in life. Better understanding the developmental processes which take place in utero and the effects they have later in life may help us create management plans that utilize grazing animals to their full potential as landscape manipulators.

Using in utero and early-life programming as a management tool is a relatively new concept, …

The Utah Forest Dynamics Plot: Long-Term Ecological Monitoring And Theoretical Ecology In A High-Elevation Subalpine Environment, Tucker J. Furniss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Unified Neutral Theory of Biodiversity has been advanced as a universal theory for species coexistence in forests worldwide, but few studies have examined its relevance to high-elevation, stressful environments. I established the Utah Forest Dynamics Plot (UFDP) in a heterogeneous subalpine forest at 3,091 m elevation on the Colorado Plateau to examine three underlying assumptions of neutral theory (functional equivalence, ecological equivalence, and habitat generality) and one prediction (the species abundance distribution). The UFDP comprises 27,845 stems ≥1 cm diameter at breast height of 17 species, 10 genera, and 6 families over 13.6 ha. The neutral model was a …

Spatial Ecology And Captive Behavior Of Rehabilitated Black Bears In Utah, Patrick J. Myers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Animal movements and space use are fundamental components of life and play integral roles in organismal fitness, population dynamics, and the ecology and evolution of species. The heterogeneous distribution of resources and the movement required to access them, results in ecology being a fundamentally spatial concept. Thus, elucidating animal-habitat relationships is a central focus of wildlife ecology and conservation. I utilized GPS technology, resource selection functions, and generalized linear mixed models, to investigate the immediate post-release movements, denning chronology, release-site fidelity, and season-delineated movements, home ranges, and resource use for six, orphaned and rehabilitated black bears (Ursus americanus). …