Ecology and Evolutionary Biology Commons^™

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 …

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 …

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, …

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 …

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 …

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 …

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 …

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 …

Structural And Compositional Patterns In Forest Communities In The Intermountain West Across Multiple Scales, Marcella A. Windmuller-Campione

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The United States Department of Agriculture (USDA) strives to use science-based research to both protect and enhance the management of natural resources. From this overarching goal, the USDA has a specific objective to protect the health and sustainability of forest and rangeland ecosystems. Based on this specific objective, an Advisory Board of natural resource scientists within the Quinney College of Natural Resources (QCNR) was awarded a National Institute of Food and Agricultural (NIFA) grant to train two PhD and two MS students. Their research would focus on managing for resilient forest ecosystem in the Intermountain West.

With input from the …

Ecology, Behavior And Taxonomy Of Anurans From Brazil's Atlantic Forest, Rodrigio Barbosa Ferreira

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Anura is a diverse group with more than 7382 species described, which represents 88% of the species belonging to the Class Amphibia. Anurans are among the first organisms to be affected by environmental stressors, so when they show decline in the wild, it is a warning to other species, including humans. It is alarming that one-third of the world’s anurans are facing extinction. Following the same trend, a substantive portion of the 988 recognized species of the Atlantic Forest have suffered population declines and local extinctions, attributed primarily to habitat changes.

Despite the unique life history characteristics that make amphibians …

Matching Watershed And Otolith Chemistry To Establish Natal Origin Of An Endangered Desert Lake Sucker, Deanna Strohm

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Like many native endemic desert freshwater fish species, the June Sucker (Chasmistes liorus) is currently listed as endangered. Managers have increasingly turned to habitat restoration as a key component to recovery plans. For endangered species, one of the primary outcomes of habitat restoration is that it should result in successful reproduction and recruitment of individuals into the adult population. Confirmation of natural recruitment as a function of habitat restoration can only be achieved by establishing natal origins.

Recent research has proven the validity of otolith microchemistry, a technique that analyzes small quantities of elements, to trace potamodromous fish …

Greater Sage-Grouse Seasonal Habitat Models, Response To Juniper Reduction And Effects Of Capture Behavior On Vital Rates, In Northwest Utah, Avery Cook

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The greater sage-grouse (Centrocercus urophasianus; sage-grouse) is a species of conservation concern in Utah and across their range throughout the western US and southern Canada. Sage-grouse decline is primarily a result of declines in sagebrush habitat on which sage-grouse depend for winter, summer, nesting, and brood habitat. Detailed site-specific knowledge of sage-grouse ecology and distribution in needed to effectively conserve the species. To expand knowledge of local populations within the West Box Elder Sage Grouse Management Area (SGMA) in NW Utah and gain insights into the effectiveness of vegetation treatments intended to benefit sage-grouse, I radio marked and …

Grass-Shrub Spatial Associations Over Precipitation And Grazing Gradients In The Great Basin, Usa, Maike F. Holthuijzen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As environmental stress increases, positive plant interactions dominate, resulting in clumped, plant-plant spatial patterns. Positive plant-plant interactions have received more attention in recent years due to their importance to the structure and function of arid ecosystems. Certain plants (nurses), provide benefits that help neighboring plants grow or survive.

I investigated spatial associations between Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) and three native grasses (Poa secunda, Elymus elymoides, and Pseudoroegnaria spicata) across a rainfall gradient in the Great Basin, USA. We also explored the effect of grazing on grass-shrub spatial patterns. I hypothesized that positive …

Factors Influencing The Ecology Of Greater Sage-Grouse Inhabiting The Bear Lake Plateau And Valley, Idaho And Utah, Casey J. Cardinal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are a sagebrush obligate species and as such an indicator of sagebrush (Artemisia spp.) habitat quality and quantity. Sage-grouse populations have declined across western North America. This decline has been attributed to habitat loss and degradation of the sagebrush ecosystem. To determine factors that may cause localized declines in sage-grouse populations, managers may need site-specific information on the ecology and habitat use patterns of meta-populations. This information is currently lacking for sage-grouse populations that inhabit the Bear Lake Plateau and Valley (BLPV), encompassing parts of Idaho, Utah and Wyoming. I captured, radio-marked …

Trophic Status, Energetic Demands, And Factors Affecting Lahontan Cutthroat Trout Distribution In Pyramid Lake, Nevada, Nicholas A. Heredia

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The progression of human development across the landscape has caused declines to both terrestrial and aquatic fauna. Many fishes, specifically native salmonids, have seen reductions in both population size and geographic distribution resulting from reduced habitat, overharvest, and the introduction of non-native predators and competitors. A native North American fish particularly hard hit by these types of actions, Lahontan cutthroat trout, are now limited to less than 10% of their historical habitat, and currently occupy only half of the lakes that they once occupied.

In Pyramid Lake, Nevada, where Lahontan cutthroat trout were once locally extinct, due to overfishing, water …

Ringtail Distribution, Dermatoglyphics, And Diet In Zion National Park, Utah, Adrian Argie Roadman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Current scientific knowledge of the ringtail (Bassariscus astutus) is limited, thus impeding appropriate management decisions. Ringtails in Zion National Park, Utah, are rarely seen, but are involved in increasing occurrences of negative interactions with park visitors and employees such as food theft and denning in buildings, interactions which are harmful to both parties. To manage this conflict, an update to the general knowledge about the status of the population is required as the only previous study on ringtails in this area was conducted in the 1960s. Using noninvasive techniques provides dependable large-scale population information. I used two noninvasive detection methods …

Habitat Characteristics Of Mexican Spotted Owls (Strix Occidentalis Lucida) In The Canyonlands Of Southern Utah, Leah R. Lewis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mexican Spotted Owls are considered a threatened species by the US Fish and Wildlife Service. Therefore, they must be properly managed and protected by federal and state agencies. In this study I explored the habitat characteristics used by Mexican Spotted Owls in the canyonlands region of southern Utah. I spent three summer field seasons (May-September) from 2010 – 2013 locating Mexican Spotted Owl sites and measuring vegetative and geologic features at these sites. I found that canyon width and very tall vegetation influenced Mexican Spotted Owl presence, suggesting that these owls prefer narrow canyons that are vegetated with trees.

Based …

The Ecosystem Role Of Fishes In Lotic Environments, Christopher C. Wheeler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It is important for humans to understand how ecosystems work because we depend on them for a variety of products and services. For example, rivers and streams provide fisheries, improved water quality, and recreational opportunities to many individuals. In rivers, interactions among fishes, other stream plants and animals, and the physical river environment can influence continued provision of these valuable services. However, the role played by many freshwater fishes in the provision of these services remains unknown. Additionally, it is important to identify different factors that affect the outcome of interactions involving riverine fishes. To address these issues, I evaluated …

Activated Carbon Decreases Invasive Plant Growth By Mediating Plant-Microbe Interactions, Nicole E. Nolan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To restore lands invaded by dense, non-native vegetation, it may be necessary to develop targeted restoration tools than can remove the mechanism used by these non-native species as a competitive advantage. Activated carbon (AC) is one such tool, with the ability to disrupt the mechanisms of plant to plant communication (allelopathy) and positive plant to microbe communication commonly used by non-native species. Previous studies have shown the success of high concentrations, 1000g/m², of AC in native plant community restoration on a small scale. Here, our goals are twofold: first, to test AC effectiveness in restoring desirable plant communities …

Movement And Habitat Use Of Bonneville Cutthroat Trout (Oncorhynchus Clarki Utah): A Case Study In The Temple Fork Watershed, Ryan L. Lokteff

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Movement patterns and habitat use of Bonneville cutthroat trout (Oncorhynchus clarki Utah) in tributaries of the Logan River watershed are greatly affected by habitat alterations created by North American Beaver (Castor canadensis). Evaluation of cutthroat trout habitat use in these watersheds is also complicated by biotic interactions with invasive brown trout (Salmo trutta) and brook trout (Salvelinus fontinalis). My objectives in this thesis were to 1.) Evaluate the passage of beaver dams by each trout species in the Temple Fork watershed and 2.) Evaluate the habitat use of cutthroat trout in the presence …

Modeling To Improve Vegetation-Based Wetland Biological Assessment, Robin C. Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To meet the requirements of the Clean Water Act (1972), natural resource managers need to be able to detect biological degradation in wetland ecosystems. Biological indices are commonly used by managers to assess wetland biological condition. The accuracy and precision of wetland condition assessments are directly related to the performance of these indices, and biological index performance is thought to be related to how well an index controls for the effects of environmental attributes on biological assemblages. Many plant-based biological indices control for environmental and biological variation through the use of classification schemes that are based on geographic location and …

An Evaluation Of The Relative Performance Of Diploid Versus Triploid Brook Trout With Consideration Of The Influence Of Lake Characteristics, Andy Dean

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Brook trout are native to the east and Midwestern United States. Brook trout have become a popular sport fish in the western United States and are currently widely stocked to provide sport fishing opportunities throughout the west. The Utah Division of Wildlife Resources (UDWR) regularly stocks brook trout into high mountain lakes in the Uinta Mountains to provide one of these popular fisheries. Stocking non-natives to high mountain lakes can cause competition with native species for food and habitat resources and provides source populations for dispersal of non-natives downstream. Triploid (sterile) fish may provide an opportunity to stock non-native fish …

Ecomorphological And Genetic Investigations Into The Utah Lake, Ut Sucker Complex With Comparisons To The Jackson Lake, Wy Sucker Complex, David D. Cole

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Natural selection within the sucker family of fishes has produced populations including typical benthic (bottom-feeding) suckers (Catostomus) and lakesuckers (Chasmistes), mid-water plankton eaters, in several large western North American lakes. Suckers of intermediate morphology (shape) exist in a continuum of head, mouth, and body characteristics between these two extremes. All current lakesuckers are listed Endangered, and population declines have been attributed in part to hybridization with their Catostomus neighbors.

Chapter 2 describes the investigation of the relationship between morphology and genetics of June sucker, a lakesucker, and Utah sucker, a benthic sucker, in Utah Lake, Utah. …

Usda Forest Service Perspectives On Forest Management In A Changing Climate, Jamie E. Laatsch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As climate change becomes more problematic for the Forest Service (FS) and other federal land management agencies in the U.S., it has become increasingly important to understand how their employees view climate change and related challenges. This study examined how FS employees in the Intermountain West view forest management in the face of climate change, what barriers and opportunities they see in terms of dealing with climate change, and how different levels of agency management view climate change-related issues differently. This study found that many FS employees believe climate change is an important issue; however, they have not done much …

Old Roots: Place-Making And Hybrid Landscapes Of Refugee Urban Farmers, Missy Ward-Lambert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research project was designed to analyze the relevance of place and the physical environment to the adjustment processes of refugees. This dissertation contains the results of qualitative research with a group of 30 refugee urban farmers living in Salt Lake City, Utah. Seventeen of these individuals—from Burundi, Sudan, Bhutan, the Republic of Congo, Democratic Republic of the Congo, Chad, and Cuba—participated in interviews and a photography project focused on their experiences with agriculture in their home countries and since their arrival in Utah. The results of the research show the connection between the refugees’ work as farmers and their …

Influence Of Stand Composition On Soil Organic Carbon Stabilization And Biochemistry In Aspen And Conifer Forests Of Utah, Mercedes Román Dobarco

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Social concern about climate change and the elevated level of atmospheric CO2 demands understanding carbon (C) storage and dynamics in forest soils, especially since soils are the largest C reservoir in terrestrial ecosystems, storing two thirds of total C. Quacking aspen (Populus tremuloides Michx.) is an iconic species in western United States that offers multiple ecosystem services, such as habitat and forage for wildlife and cattle, biodiversity, water yield, and C storage. A decline in quaking aspen cover has been documented during the last decades, possibly due to fire suppression and ungulate browsing. A shift from aspen- to conifer-dominated …

The Role Of Vegetation Structure, Composition, And Nutrition In Greater Sage-Grouse Ecology In Northwestern Utah, Brian R. Wing

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The greater sage-grouse (Centrocercus urophasianus; sage-grouse) is the largest grouse species in North America and an indicator species for the condition of sagebrush (Artemisia spp.) ecosystems. The Box Elder Sage-Grouse Management Area (SGMA) in northwestern Utah encompasses one of the state’s largest sage-grouse populations.

To fill knowledge gaps regarding the population inhabiting the Raft River subunit of the Box Elder SGMA, I captured, radio-marked, and monitored 123 (68 female, 55 male) sage-grouse from January 2012 through December 2013. My purpose was to describe how the seasonal movements, survival, and reproductive rates of this sage-grouse population …

Nitrogen Cycling In The Rhizosphere Of Cheatgrass And Crested Wheatgrass: Contributions Of Root Exudates And Senescence, Kendalynn A. Morris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cheatgrass is an invasive weed that has come to dominate large areas of the western United States. Once an ecosystem has been converted to a cheatgrass monoculture, it is extremely difficult to restore native vegetation. Cheatgrass negatively impacts wildlife and increases wildfire frequency and intensity. Understanding how cheatgrass so effectively invades western ecosystems is essential to turning the tide of invasion. One possible key to cheatgrass’ success is alteration of soil nutrient cycling. The goal of this study is to explore how nitrogen (N) may accumulate in cheatgrass soils via redistribution of N within soil N pools. To accomplish this …

Macroinvertebrate-Driven Nutrient Recycling In Four Large Rivers, Matt A. Schroer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The cycling of nutrients is a fundamental process in streams and rivers, and scientists are increasingly recognizing the importance of animal communities to nutrient dynamics in these ecosystems. Despite growing evidence that animal excretion (i.e. urine) can supply limiting nutrients to primary producers in small streams, the importance of excretion is uncertain in large rivers. Accordingly, I used three estimation approaches based on past and new excretion rate data to determine nitrogen (N) and phosphorus (P) excretion inputs from insect communities in four large rivers (discharge > 10 cubic meters per second) in North America, and I compared these rates to …

Estimating Baseline Population Parameters Of Urban And Wildland Black Bear Populations Using A Dna-Based Capture-Mark-Recapture Approach In Mono County, California, Jonathan L. Fusaro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Prior to European settlement, black bear (Ursus americanus) were far less abundant in the state of California. Estimates from statewide harvest data indicate the California black bear population has tripled in the last 3 decades. Bears inhabit areas they formally never occurred (e.g., urban environments) and populations that were at historically low densities are now at high densities. Though harvest data are useful and widely used as an index for black bear population size and population demographics statewide, it lacks the ability to produce precise estimates of abundance and density at local scales or account for the numerous …