Ecology and Evolutionary Biology Commons^™

Distribution And Drivers Of A Widespread, Invasive Wetland Grass, Phragmites Australis, In Great Salt Lake Wetlands, Arin Lexine Long

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Non-native invasive plant species can often have negative effects on native ecosystems, such as altered nutrient cycling, decreased habitat for wildlife, and outcompeting native plants. Around the Great Salt Lake (GSL), Utah, the invasive wetland grass Phragmites australis has become abundant in wetlands around the lake. Phragmites is replacing many native wetland plants provide important waterfowl habitat around the GSL. For successful management of Phragmites in GSL wetlands, it is important to know the current distribution of Phragmites, as well as areas that might be vulnerable to future invasion by Phragmites. To do this, we used multispectral aerial …

Use Of A Net Rate Of Energy Intake Model To Examine Differences In Juvenile Steelhead (Oncorhynchus Mykiss) Densities And The Energetic Implications Of Restoration, C. Eric Wall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Bonneville Power Administration (BPA) Fish and Wildlife Program mitigates for impacts of hydroelectric dams on ESA-listed salmon and steelhead populations in the Columbia River Basin (CRB). Considering the sizable investments in mitigation and the diversity of stream habitats within the CRB, there has been a pointed effort to develop and identify meaningful metrics relating to fish populations and trends in their habitat across the CRB. The Integrated Status and Effectiveness Monitoring Program (ISEMP) was developed in 2003 specifically for this purpose, and is tasked with developing and testing strategies for determining the status and trend of salmonid populations and …

Effect Of Predator Removal On Greater Sage-Grouse (Centrocercus Urophasianus) Ecology In The Bighorn Basin Conservation Area Of Wyoming, Elizabeth Kari Orning

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The decline of greater sage-grouse distribution and population densities across western North America has led conservation, research, and management objectives to focus efforts on understanding sage-grouse populations across their range. The purpose of this study was to gain a better understanding of direct and indirect predation effects on hen survival and nest success of sage-grouse. The project was conducted in Hot Springs and Park Counties in the Bighorn Basin of Wyoming. The study had three main objectives: 1) obtain and quantify the types and impacts of predators on sage-grouse hen survival and nest success, 2) compare the effect predator removals …

Climate Change And Plant Demography In The Sagebrush Steppe, Aldo Compagnoni

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We used demographic methods to address one of the main challenges facing ecological science: forecasting the effect of climate change on plant communities. Ecological forecasts will be crucial to inform long-term planning in wildland management and demographic methods are ideal to quantify changes in plant abundance. We carried out our research in the sagebrush steppe, one of the most extensive plant ecosystems of Western North America. Our research intended to inform ecological forecasts on an exotic invader, cheatgrass (Bromus tectorum). Moreover, we investigated the general question asking: to what degree competition among plants influences the outcome of ecological …

Presence And Function Of Tetrodotoxin In Terrestrial Vertebrates And Invertebrates, Amber N. Stokes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tetrodotoxin (TTX) is a potent neurotoxin found in a variety of species. This toxin has long been of concern to human health as it is found in puffer fish, which are a delicacy in Japan. Since the distribution of this toxin is so great, there are many questions regarding the evolution and ecology of organisms that have TTX. My research has focused on further investigating three topics with this research: production, predation, and identification of novel TTX bearing taxa. In order to perform this research I first refined a Competitive Inhibition Enzymatic Immunoassay methodology to quantify levels of TTX in …

The Ecology And Genetics Of Schoenoplectus Maritimus, An Important Emergent Macrophyte, Across Diverse Hydrologic Conditions—Implications For Restoration, Amanda Clare Sweetman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wetlands in the Intermountain West are typically dominated by large monotypic stands of emergent wetland plants, are highly productive, and support millions of migratory birds as important stops along the Pacific Flyway. In systems with low species diversity, such as these, diversity within a species (intraspecific diversity) can play an important role in population fitness and ecosystem functioning and can impact restoration success. Our research was designed to inform future restoration and management activities by studying the pattern of diversity within and among natural plant populations, and by studying how hydrology and plant materials used in restoration (source and diversity …

Modeling Habitat Use Of A Fringe Greater Sage-Grouse Population At Multiple Spatial Scales, Anya Cheyenne Burnett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) are a prominent bird species of sagebrush-dominated landscapes across the western United States. Over the past 15 years, sage-grouse have gained international attention due to decreasing population trends despite management efforts. In 2010 the U.S. Fish and Wildlife Service designated this species as warranted for listing under the Endangered Species Act, but the listing was precluded by other species at higher conservation risk. Habitat loss, degradation, and fragmentation have been implicated as primary sources of declines in sage-grouse distribution and abundance. The Bald Hills population in southwestern Utah occupies an area with …

Self-Limitation As An Explanation For Species' Relative Abundances And The Long-Term Persistence Of Rare Species, Glenda Marie Yenni

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecological theories often hinge on species interactions, or how the species in an area "see" other species with whom they have to share food and space. Despite the contributions theoretical coexistence models have made to our understanding of species coexistence, it can still be difficult to match these theories with data from real communities. For example, we know of many species that are very rare where they occur. Theory predicts that these species should quickly go extinct, but they do not. I use simulations and real data to show that rare species are rare because they are more self-limiting. Self-limitation …

Interspecific Interactions Between Penstemon Palmeri And Shrubs In The Arid Shrublands Of The Spring Mountains, Nevada, Jesse M. Poulos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A project involving shrub removal was undertaken by the United States Forest Service in the Spring Mountains National Recreation Area (SMNRA) to reduce accumulated woody fuels, which can pose risks to human communities. The SMNRA is also home to a variety of species that occur within these fuel reduction boundaries and are protected under the Multiple Species Habitat Conservation Plan (MSHCP) of Clark County, Nevada. It is unknown how MSHCP covered species will respond to shrub removal. This research focuses on the interactions between shrubs and the herbaceous plant Palmer’s penstemon (Penstemon palmeri), one of many nectar sources …

Causes And Consequences Of Local Variability In Aroga Websteri Clarke Abundance Over Space And Time, Virginia L.J. Bolshakova

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sagebrush steppe habitat is rapidly declining in the Intermountain West in both quality and quantity. Observed reductions in animal and bird populations associated with sagebrush, invasion of exotic annual grasses such as cheatgrass (Bromus tectorum), and other concerns with climate change have led to a growing awareness of the need to monitor and better understand the rate of habitat loss. Sagebrush lands are subject to periodic loss caused by insect feeding damage, and human activities have the potential to promote unnaturally high levels of such loss. The sagebrush defoliating Aroga moth, Aroga websteri Clarke (Lepidoptera: Gelechiidae), can kill …

Forest Recovery, Nutrient Cycling And Carbon Sequestration In A Southern Appalachian Spruce-Fir Forest, Patrick T. Moore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Our forests provide us with a variety of services from clean water, forest products and wildlife habitat to the lesser known functions of nutrient cycling and carbon
sequestration. This research helps to demonstrate the extent of some of these services in a heavily disturbed southern Appalachian spruce-fir forest within Great Smoky Mountain National Park, the most heavily visited National Park in the United States. Following a catastrophic infestation of the non-native balsam wooly adelgid, the future of this forest was unknown, causing some to speculate about the future of this sensitive forest type. Though predictions about this forest’s future varied …

A Multi-Scale Investigation Of Factors Limiting Bull Trout Viability, Tracy Bowerman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent declines in many species of aquatic organisms have raised concerns about loss of biodiversity in river systems and the need to protect populations in peril. To conserve endangered species, scientists need to know information about the habitats organisms use throughout their life cycle and how environmental stressors cause populations to grow or decline. The goal of this research was to improve our understanding of the life-cycle requirements for bull trout (Salvelinus confluentus), a threatened freshwater fish species. I assessed environmental factors that affect bull trout egg incubation success and quantified juvenile bull trout movement patterns and survival …

Effects Of Non-Surface-Disturbing Restoration Treatments On Native Grass Revegetation And Soil Seed Bank Composition In Cheatgrass-Invaded Sagebrush-Steppe Ecosystems, Alexandra D. Reinwald

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The sagebrush-steppe communities of the Great Basin have been dramatically transformed by the invasion of the non-native annual grass cheatgrass. In many areas of the Great Basin, this invasion has resulted in the loss of native plant species and ultimately the conversion to cheatgrass-dominated communities. As healthy sagebrush communities provide multiple ecosystem services such as diverse wildlife habitat, forage for cattle grazing, and water filtration, restoration of these communities is a high priority to landowners and land management agencies. Established perennial grasses can successfully compete with non-native annual grasses and increase the resistance of plant communities to invasion by non-native …

The Role Of Fine-Scale Habitat Associations In Structuring Spider Assemblages: Determinants Of Spatial Patterns In Community Composition, Stephanie M. Cobbold

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecologists strive to identify the mechanisms that drive the identity and abundance of species in different locations, because a better understanding of such factors enables them to better predict the effects of habitat modification on organisms, and to identify landscapes in which species are likely to benefit from conservation interventions. However, there is still no consensus on the mechanisms behind geographical variation in species diversity. The primary objective of this dissertation was to focus on spider assemblages to investigate how the fine-scale habitat associations of organisms may drive the composition of their communities at larger scales. Research was conducted in …

A Coupled Human And Natural Systems Approach To Understanding An Invasive Frog, Eleutherodactylus Coqui, In Hawaii, Emily A. Kalnicky

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Human activities worldwide have altered nature in ways that create new combinations of species and environmental processes. To understand so-called "novel ecosystems" it is important to consider both the natural and the societal factors that shape them, and how those factors are interconnected or "coupled." We used such an approach to explore options for managing a non-native invasive frog, the coqui, which has become established on the island of Hawaii and threatens to spread to other parts of the state.

The nighttime calls of the coqui create a nuisance for property owners when populations become dense enough, as often occurs …

Effects Of Tannin-Containing Feed On Haemonchous Contortus In Sheep And Its Behavioral Implications, Jessica A. Juhnke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Herbivores prefer foods that supply required nutrients and avoid those with excess nutrients and plant secondary compounds (PSC). Nevertheless, PSC such as condensed tannins can provide beneficial medicinal effects to herbivores. The objectives of this study were to determine: 1) if parasitized lambs increased preference for a tannin-rich food after they experienced the beneficial antiparasitic effects of tannins relative to parasitized lambs that did not experience such benefits, 2) if preference for the tannin-containing food in the former group decreased when parasite burdens subsided, and 3) if the tannin-enriched food decreased parasitic burdens.

Twenty-two lambs were familiarized with beet pulp …

Have Introduced Brown Trout (Salmo Trutta) Affected Native Aquatic Vertebrates In Western United States Streams?, Nora K. Burbank

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The introduction of exotic species to areas outside of their native range is one of the greatest threats to the biodiversity of native freshwater organisms. Exotic species have outcompeted native species for resources such as food and shelter, and in some cases these interactions have resulted in local extinctions or reductions in abundance of those native species. Brown trout are native to Eurasia, but have been introduced to much of the rest of the world, including the United States. In some parts of their introduced range, brown trout have substantially reduced the abundance and home ranges of some native fish …

Isotopic Tracer Reveals Depth-Specific Water Use Patterns Between Two Adjacent Native And Non-Native Plant Communities, Clémence Pascale Warren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Non-native plants have invaded over 100 millions of acres of western arid land in the US and dramatically altered nutrient cycling rates. Changes in water cycling caused by invasive species are of particular interest because primary production in the Western US is typically limited by water availability and aquifer recharge reflects plant demand. Large-scale invasions can, therefore, be expected to cause large-scale changes in hydrological cycles, but until recently, there have been considerable limitations in the ability to measure the timing, location, and extent of water use. Here we injected a tracer, deuterated water (D₂O), into five soil …

An Assessment Of Vegetation Metrics And Plot Types To Measure Seasonal Variation And Grazing Effects On Riparian Plant Communities, Caroline M. Laine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Monitoring changes in vegetation is important on public lands. Observing how plant communities respond to changes in land management can give insightful information about which management practices are sustainable. Because water is scarce in the western United States, many land managers focus their monitoring efforts along streams. However, monitoring streamside vegetation is challenging due to a variety of factors and can be confounded by factors such as seasonal climate variation and management activities, like cattle grazing.

In vegetation assessment, there are a variety of measurements that are taken to glean valuable information. Some attributes of interest include how much vegetation …

Using Species Distribution Models To Assess Invasion Theory And Provide Management Recommendations For Riparian Areas In The Eastern Columbia And Western Missouri River Basins, Diane R. Menuz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Globalization has created opportunities for plant and animal species to be transported to novel ecosystems. A subset of these species become invasive species, which are able to persist and spread rapidly to become influential components in their new ecosystems. Invasive species are often able to out-compete co-occurring native species and can alter fundamental ecosystem properties, such as soil nutrient availability or time between wildfires in a region. The United States is estimated to lose $34 billion per year to invasive plant species through costs to control unwanted species and lowered crop and forage production.

We used statistical models to better …

Effects Of Non‐Surface‐Disturbing Treatments For Native Grass Revegetation On Cheatgrass (Bromus Tectorum L.) Metrics And Soil Ion Availabilities, Jan C.R. Summerhays

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several restoration methods intended to increase the success of aerially‐seeded perennial grasses were assessed to determine their effects on cheatgrass metrics and soil nutrient bioavailabilities. These methods were: 1) imazapic herbicide application (140 g ai ∙ ha^-1, 210 g ai ∙ ha^-1, and no application [control]), 2) vegetation manipulation treatments (50% sagebrush overstory thinning, 100% sagebrush overstory thinning, sagebrush overstory and/or vegetative thatch burning, and no manipulation [control]), and 3) alternative seeding treatments (aerial seeding with raking, aerial seeding with activated carbon [AC] addition, aerial seeding with sucrose addition, and regular aerial seeding [control]). Treatments were …

Community Level Effects Of Vegetation Architecture And Prey Availability: A Study Of Ground-Dwelling Arthropods In A Shrub-Steppe Ecosystem, Mary E. Pendergast

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes to vegetation architecture within a natural habitat can have profound impacts upon ecological community function, but the relative influence of vegetation architecture itself and potential indirect influences of associated food resources are often difficult to disentangle. I present the results of a three-year study designed to address the community level impacts of changes in big sagebrush (Artemisia tridentata) architecture and associated prey availability upon the ground-dwelling arthropod community. Three experimental sagebrush architecture treatments (low, intermediate, and high foliage density) and two levels of prey insect availability treatment (natural and baited/increased prey availability) were imposed in a sage-steppe …

Individualistic Response Of Piñon And Juniper Tree Species Distributions To Climate Change In North America's Arid Interior West, Jacob R. Gibson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Piñon and juniper tree species have species-specific climatic requirements, resulting in unique distributions and differential responses to climate change. Piñons and junipers co-dominate the arid woodlands of North America as groups with widespread hybridization. Two piñons, Pinus edulis; P. monophylla, and four junipers, Juniperus deppeana var. deppeana; J. monosperma; J. occidentalis; J. osteosperma, are endemic to the midlatitude interior west and form three groups of hybridizing sister species, P. edulis-P. monophylla; J. deppeana var. deppeana-J. monosperma; J. occidentalis-J. osteosperma. Recent droughts have caused widespread mortality among piñons, but have had less impact on …

Riparian Bird-Habitat Association Models: A Framework For Informing Management And Developing Restoration Guidelines In Utah, Hillary M. White

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Approximately 75% of the avian species in Utah use riparian habitats at some time during their life cycles and at least 80% of this habitat in Utah has been lost or altered since settlement; currently 0.6% of land cover in Utah is considered riparian. In 1992, with the support of Utah Partner's in Flight, the Utah Division of Wildlife Resources began a statewide neotropical migratory bird (NTMB) and habitat monitoring program to assess the status of bird populations at 31 sites. Additional sites (up to 52) were added in later years; bird and habitat assessments at 37 riparian sites have …

Behavioral Responses Of Willow Flycatchers, Empidonax Traillii, To A Heterogeneous Environment, Amanda V. Bakian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spatial heterogeneity impacts population and community-level dynamics including species-level dispersal patterns, the use and availability of refugia, predator/prey dynamics, and reproductive fitness. Understanding how wild animal populations respond to environmental heterogeneity is essential for their proper management and conservation. In this study, I examine the responses of Willow Flycatchers to spatial heterogeneity in the distribution of their food and habitat resources. Over the course of three breeding seasons, I radio- tracked Willow Flycatchers at Fish Creek in Manti-La Sal National Forest in Utah, recorded detailed behavior data at each radio location, and collected fecal, feather and insect samples. I formulated …

Habitat Characteristics And Occupancy Rates Of Lewis's Woodpecker In Aspen, Amy M. Vande Voort

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lewis‘ woodpeckers (Melanerpes lewis) are generally associated with open ponderosa pine (Pinus ponderosa), open riparian, and burned pine habitats in the West; however, this species has recently been found to nest in aspen (Populus tremuloides) stands in Utah. This study describes the habitat characteristics of Lewis‘ woodpecker nest sites in aspen and investigates how well aspen stand characteristics predict Lewis‘ woodpecker occupancy. I surveyed for Lewis‘ woodpeckers at previously occupied nesting locations in aspen and took habitat measurements at nest sites. In addition, nest-centered Forest Inventory and Analysis (FIA)-type plots provided stand-level habitat characteristics. I used logistic regression to …

Temperature Increase Effects On Sagebrush Ecosystem Forbs: Experimental Evidence And Range Manager Perspectives, Hilary Louise Whitcomb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sagebrush plant communities are among the most threatened in North America. This project had two goals: to test how increased temperature affects native and nonnative forb species common to the Western sagebrush region and to evaluate land manager beliefs about changes in their ecosystems, including those affecting forb species.

Native forbs Sphaeralcea munroana, Crepis acuminata, Linum lewisii, Penstemon palmeri, and Oenothera pallida and non-natives Erodium cicutarium and Lactuca serriola were each subjected to two treatments: experimental warming using open-top chambers and a control. Knowing how forbs used in restoration might respond to future conditions is both …

Diet, Density, And Distribution Of The Introduced Greenhouse Frog, Eleutherodactylus Planirostris, On The Island Of Hawaii, Christina A. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The greenhouse frog, Eleutherodactylus planirostris, native to Cuba and the Bahamas, was recently introduced to Hawaii. Studies from other invaded habitats suggest that it may impact Hawaiian ecosystems by consuming and potentially reducing endemic invertebrates. However, there have been no studies on the greenhouse frog in Hawaii. The first component of this study was to conduct a diet analysis. We conducted a stomach content analysis of 427 frogs from 10 study sites on the island of Hawaii. At each site, we also collected invertebrates using two different sampling methods: leaf litter collection and sticky traps to characterize available resources. …

15n Tracer And Modeling Analyses Of Nutrient Transport Through Lakes In A Subalpine Watershed, David M. Epstein

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lakes have historically been overlooked as important nutrient processors within their watersheds. In general ecologists have focused on streams as zones of uptake and transformation, while viewing lakes as simple nutrient traps. However, recent research has highlighted the large influence that lakes may have on water chemistry within their watersheds. Within the field of limnology, researchers have traditionally focused on the pelagic zone for in-lake production. Further research in shallow lakes has highlighted the role benthic production within the littoral zone plays in the lake ecosystem. The greater influence of lakes is highlighted when comparing watersheds containing lakes with watersheds …

Ecology And Conservation Of Cougars In The Eastern Great Basin: Effects Of Urbanization, Habitat Fragmentation, And Exploitation, David C. Stoner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research was designed to investigate cougar response to urbanization, habitat fragmentation, and exploitation from behavioral, demographic, and landscape perspectives. The source-sink model has been proposed as an alternative framework for the management of exploited cougar populations. I addressed the basic question of whether cougars conform behaviorally to the predictions of the source-sink model, and consequently, the applied question of whether the model could be used for the conservation of this species. To achieve this I evaluated three scale-specific questions using radio-telemetry and hunter-harvest data collected from 1996-2010. At the subpopulation scale, I tested the hypothesis that cougars are wildland …