Ecology and Evolutionary Biology Commons^™

Classification And Prediction Models For Natural Streamflow Regimes In The Arid Southwestern Usa, Angela M. Merritt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding how natural variation in flow regimes influences stream ecosystem structure and function is critical to the development of effective stream management policies and actions. Spatial variation in flow regimes is well understood for stream reaches in mesic regions, but a more robust characterization of flow regimes in arid regions is needed, especially to support biological monitoring and assessment programs. Methods are specifically needed that can accurately predict the flow regime expected at ungauged reaches. We used long-term (41 y) records of mean daily flow from 287 stream reaches in the arid western USA to develop and compare several alternative …

Applied Species Delimitation In Microbial Taxa And Plants, Austin C. Koontz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Species are a fundamental concept in biology, and many subdisciplines in biology utilize species in aspects of theory and in the communication of results. Given the centrality of species in biological science, it can seem surprising that there is no universal definition amongst biologists of what, strictly speaking, a species is. In fact, there are, by some estimates, over 20 different "species concepts", and this lack of a consensus is termed "the species problem". This problem has theoretical underpinnings, but has become more relevant as advances in sequencing technologies over the past two decades have allowed researchers to probe the …

Influences Of Forest Edges On The Growth And Health Of Old-Growth Coast Redwood Forests, Cody R. Dangerfield

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coast redwood (Sequoia sempervirens) is the tallest species in the world, frequently attaining heights greater than 300 ft. The unique characteristics of the redwoods has led to the establishment of several preservation areas including national and state parks. However, abrupt forests edges created by previous logging and landcover changes has left the remaining stands exposed to elevated temperature, sunlight, and wind intensities, thereby making redwoods along the forest edge more susceptible to windthrow and drought stress. Despite the rarity of old-growth coast redwood forests and their ecological and cultural significance, very few studies have investigated how forests edges …

Effect Of Biocrust Development On Establishment Of Native Plants In A Salt Desert System, Merran Owen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Salt desert shrublands are semiarid, shrub-dominated ecosystems that inhabit salt- affected soils. In Great Basin salt deserts, exotic annual plants are invading and displacing native plants. Low plant productivity and slow population growth of native plants in these ecosystems makes them vulnerable to invasion and limits their ability to compete with invasive plants and return to a natural state. Active revegetation efforts, such as planting and direct seeding of native plants, are often unsuccessful for the same reasons. Biological soil crusts (communities of cyanobacteria, lichen, moss, microfungi and other microorganisms that live on the surface layer of the soil) are …

The Consequences Of Environmental Properties And Tree Spatial Neighborhood On Post-Fire Structure Of Forest In Yosemite National Park, Jelveh Tamjidi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Separating the contribution of habitat filtering and dispersal mechanisms in forming species distribution remains a challenge in community ecology. Despite the effect of environmental variables in structuring communities, only restricted numbers of them were considered as a habitat dissimilarity.

In Chapter 2, I used topography and soil properties to define habitats within the Yosemite Forest Dynamics Plot (YFDP). The soil enzymes were added in soil samples due to their important role in releasing nutrients into the soil environment. The preference of eleven species to a specific habitat were examined. Also, the relative importance of habitat filtering and dispersal limitation were …

Harmful Algal Blooms: Dominance In Lakes And Risk For Cyanotoxin Exposure In Food Crops, Austin D. Bartos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate change and human activities are promoting the dominance of a photosynthetic family of aquatic bacteria, cyanobacteria. Blooms of cyanobacteria are not only a visual nuisance but can produce a variety of cyanotoxins than can harm the liver, skin, and nervous system of animals and humans. We analyzed lakes in the contiguous United States and found that between 2007 and 2012, the number of lakes that produced measurable quantities of cyanotoxins increased from 33% to 45%. Nitrogen and phosphorus pollution were the main drivers of cyanobacteria blooms and toxin production between these years. Many of these lakes and reservoirs are …

Anthropogenic Influences On Bacterial Assemblages In Stream Biofilms, Elizabeth M. Ogata

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bacteria within biofilms are an essential component of stream ecosystems, influencing the movement of carbon (C), nitrogen (N), and phosphorus (P) in watersheds. To better understand the ecological effects of human activities on stream ecosystems, my research examined how nutrients and pharmaceuticals, common pollutants in streams worldwide, influence bacterial assemblages in stream biofilms. First, I tested how nutrients (N, P, iron) and pharmaceuticals (caffeine, diphenhydramine) influenced biofilm bacterial microbiomes (taxa present in at least 75% of samples of a contaminant treatment). Nutrients allowed taxa known for their ability to thrive in nutrient-rich environments to dominate microbiomes, pharmaceuticals supported a rich …

Impacts Of Tourism On The Ecophysiology Of The Endangered Northern Bahamian Rock Iguana (Cyclura Cychlura), Alison C. Webb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Increased interest in ecotourism over recent years has led to more direct human-animal interactions and a striking concomitant increase in the provisioning of non-natural food, that may have unintended consequences for the wildlife involved. The critically endangered Northern Bahamian Rock Iguana provides a valuable model to address the potential impact of food provisioning on health as there are populations that represent a graded variation in human presence, with sites experiencing high, low, or no tourism. To assess the potential impacts of tourism on iguana physiology I first reviewed the relevant literature on iguana physiology and then performed three investigations focusing …

Improving Our Ability To Estimate Vital Rates Of Endangered Fishes On The San Juan River Using Novel Applications Of Pit-Tag Technology, J. Benjamin Stout

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Estimating demographic parameters, such as survival and abundance, with accuracy and precision is vital for detecting trends in populations and assessing the effectiveness of management actions. In most cases, a lack of capture data make estimating parameters very challenging. The use of new technologies to increase the amount of remotely collected data is increasing, but brings new limitations and analytical issues to be resolved. One of those new technologies is the use of a mobile floating PIT-tag antenna to detect PIT-tagged fish. The issue that arises with this technology is determination of the status of detected tags (i.e., live fish …

Harvest Efficiency Of Forage Grazed By Cattle And The Effect Of Pinyon And Juniper Treatments On Vegetation Cover On The Grand Staircase Escalante National Monument, Ruger P. Carter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Grand Staircase Escalante National Monument (GSENM), located in central south Utah, currently has 76,957 active grazing animal unit months on the monument. Recently, there has been questions whether the harvest and grazing efficiency coefficients developed in the Midwest are applicable to the arid, bunch grass dominated systems of the GSENM. Harvest and grazing efficiency defines the percentage of allocated forage that is being ingested by the animal, and the percentage that is being wasted. Harvest and grazing efficiency coefficients were calculated on the Lower Cattle allotment on the GSENM by taking total forage production and dividing that by expected …

Improving Aquatic Habitat Representation In Utah Using Large Spatial Scale Environmental Datasets, Gregory C. Goodrum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rivers provide habitat for aquatic species, but widespread human water development degrades aquatic habitat, fragments stream networks, and threatens native fish populations. Habitat suitability models are commonly used to identify current instream habitat conditions, but are often species-specific, data-intensive, and rarely suitable to the large spatial scales required in conservation and water resources management. Thus, there is need to develop and validate habitat suitability models that provide ecologically-meaningful estimations of aquatic habitat, but are simple enough to apply at large geographic areas and flexible to incorporate different species. I tested the accuracy of 15 habitat suitability models estimating Bonneville Cutthroat …

Ecoacoustic Methods For Multi-Taxa Animal Surveys In The Amazon, Leandro A. Do Nascimento

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tropical regions host most of the biodiversity found on Earth, but these species-rich areas are constantly threatened by human development and other disturbances that put this diversity of life forms at risk. To avoid extirpations of animal and plant species, scientists and managers rely on accurate monitoring techniques to retrieve information about population trends. This task is not easy, especially in the tropics, where there is often a lack of personnel to conduct surveys, a lack of funding, and the areas are so extensive that many countries need to be involved in monitoring (e.g., Amazon biome). For this reason, scientists …

A Data-Driven Regional Model Of Stomatal Conductance For Kruger National Park, Rebecca L. Tobin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Stomata are the gateway between the lithosphere, the biosphere, and the atmosphere. Because of photosynthesis, plants inevitably lose water through their stomata. The rate at which water moves through stomata is stomatal conductance. As stomatal conductance increases, the rate of CO₂ assimilation increases, therefore, plants must reach a balance between acquiring CO₂ and losing H₂O. Plants achieve this balance by adjusting stomatal aperture. Therefore, modeling stomatal conductance is important to global circulation models and land surface models, as well as for predicting how changing climate conditions affect water use efficiency and plant productivity, and has implications …

Ecology And Economic Impact Of The Invasive Brown Marmorated Stink Bug (Hemiptera: Pentatomidae; Halyomorpha Halys) In The Utah Agricultural Landscape, Zachary R. Schumm

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The brown marmorated stink bug (BMSB) is a major insect pest that causes economic loss to a diversity of U.S. fruit and vegetable crops, and invades homes and human structures, causing nuisance issues for homeowners. This destructive insect causes millions of dollars of crop damage annually, and is difficult to manage due to its resistance to some common insecticides. BMSB is a relatively new pest to Utah, and its biology and ecology is not well known in the high elevation, arid Intermountain West region. In Chapter II, I explored the potential impact of BMSB to tart cherry, an unstudied crop …

The Utility Of Environmental Dna And Species Distribution Models In Assessing The Habitat Requirements Of Twelve Fish Species In Alaskan North Slope Rivers, James B. Eddings

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Subsistence fishing is a vital component of Alaska’s North Slope borough economy and culture that is being threatened by human disturbance. These threats mean the fish must be protected, but the size of the region makes conservation planning difficult. Fortunately, advances in species distribution models (SDMs), environmental DNA (eDNA), and remote sensing technologies provide potential to better understand species’ needs and guide management. The objectives of my study were to: (1) map the current habitat suitability for twelve fish species, occurring in Alaska’s North Slope, (2) determine if SDMs based on eDNA data performed similarly to, or improved, models based …

Interspecific Differences In Stressor Tolerance Drive Community-Level Changes In A Small Aquatic Ecosystem, Jennifer M. Weathered

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The global human population is expected to reach 9.8 billion by 2050 and an increase in food yield will be needed to provide for the future generations. Insects are among the biggest threats to food production and are therefore the subject of intense chemical control through the application of pesticides. The ability of insects to evolve resistance to pesticides after repeated use has been documented. However, how evolved responses affect individuals’ behaviors, their interactions with others, and how these factors impact overall patterns in distribution remains relatively unexplored in the bromeliad.

The aquatic insect communities housed in water-holding tropical plants …

Disease Ecology And Adaptive Management Of Brucellosis In Greater Yellowstone Elk, Gavin G. Cotterill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Brucellosis is a bacterial infection that primarily affects livestock and can also be transmitted to humans. In the Greater Yellowstone Ecosystem (GYE), elk (Cervus canadensis) and bison (Bison bison) are habitual carriers of Brucella abortus, which arrived to the region with cattle over a century ago. The disease was eliminated from cattle in the United States through widespread control efforts, but is now periodically transmitted back to cattle on open rangelands where they can come into contact with fetal tissues and fluids from disease-induced abortions that occur among elk during the late winter and spring. …

An Evaluation Of Management Options For The Clover Root Curculio (Sitona Hispidulus), A Pest Of Alfalfa (Medicago Sativa) In The Intermountain West, Kaitlin A. Rim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The clover root curculio (CRC) is an important forage pest throughout North America. Extensive larval feeding on host roots has been associated with reduced stand establishment, disruption of nutrient and water uptake, increased secondary plant pathogen infection, decreased winter plant survival, and reductions in forage quality and yield. Due to the hidden nature of larvae in the soil, CRC is often overlooked and integrated pest management programs are limited as there is a lack of management options. First, I surveyed northern Utah alfalfa for CRC natural enemies, particularly insect-attacking nematodes and fungi (entomopathogens) that could be used in biological control …

Forage Inventory And Modeling In Uintah And Ouray Reservation Rangelands, Scott N. Zimmer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Uintah and Ouray Reservation in northeastern Utah has not been widely studied, and access to non-tribal members is highly restricted. We sampled vegetation to summarize condition in 300,000 acres of unsurveyed Reservation lands in 2017-2018, combining these data with data collected by the Bureau of Indian Affairs from 2010-2015 to complete an initial rangeland vegetation inventory of the Reservation. This survey was designed to inform management of the area by determining cattle stocking rates and overall ecological condition across the Reservation. Both the density of forage available to cattle and appropriate cattle stocking rates vary greatly throughout management units …

An Evaluation Of Arthropod Assemblages In Great Salt Lake Wetland Habitats: Differences Between Native And Invasive Vegetation And Implications For Restoration, Emily E. Leonard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wetlands provide important habitat for various birds. Invasive plants can disrupt wetland food webs by altering the arthropod assemblages (invertebrate animals such as spiders, mites, insects, centipedes, and millipedes) on which these birds rely. However, differences between the wetland arthropods found in invasive vs. native vegetation are poorly defined. Wetlands are often managed for the creation of bird habitat through invasive species removal and native plant revegetation, yet few studies have examined the effects of these restoration methods on arthropod bird food sources. Phragmites australis (common reed), is an aggressive grass species in wetlands surrounding the Great Salt Lake, Utah, …

Human-Wildlife Interactions In Bryce Canyon National Park, Chad H. Wildermuth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Public lands such as National Parks protect some of America’s most spectacular and iconic natural, cultural, and historic landscapes. These lands are managed with a goal of preserving their unique features for the recreational use of the public. Therefore, it is important to understand the effects, if any, that public visitation has on these natural systems. This study investigated human-wildlife interactions in Bryce Canyon National Park (BRCA), Utah in order to better understand factors that lead to human-wildlife conflicts and how the attitudes and perceptions of visitors affect their actions towards wildlife.

Observations of human-wildlife interactions were observed and measured …

Forest Grouse Ecology And Management In The Bear River Range Northern Utah, Skyler Y. Farnsworth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To better manage dusky grouse (Dendragapus obscurus) and ruffed grouse (Bonasa umbellus), hereafter forest grouse, managers require better information on forest grouse population status and habitat selection. To address this need, from 2015-2017, I conducted research on a sympatric populations inhabiting the Bear River Range of northern Utah to develop a breeding survey protocol, assess habitat selection, evaluate dusky grouse response to livestock grazing, and determine hunter harvest rates.

The breeding census protocol that I developed compared listening intervals with and without electronic playback calls at designated survey stop locations. Using digital mapping software, I plotted …

Do Didymosphenia Geminata Blooms Affect Fishes In The Kootenai River Basin?, Niall G. Clancy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Didymosphenia geminata (Didymo) is a nuisance algae that can cover entire streambeds under certain environmental conditions. Numerous studies have shown that it changes the composition of stream invertebrates. Fishes in many headwaters are known to feed almost exclusively on invertebrates. Thus, there is concern changes to the amount or type of invertebrates caused by Didymo blooms will impact fishes such as trout, charr, and sculpin. In the Kootenai River basin of Montana and British Columbia, we examined stream invertebrates and fish diets, condition, and growth across 25 streams during the summers of 2018 and 2019. The severity of Didymo blooms …

Patterns Of Microbial Diversity And Community Composition In Slot Canyons, Rock Pools, And Other Ephemeral And Perennial Aquatic Habitats, Marley Madsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microbes are the most diverse life forms on the planet and perform many impor-tant ecological functions. However, despite the abundance, diversity, and ecological importance of microbes they are often overlooked and understudied in many natural systems, including freshwater habitats. This thesis details the first ever investigation of the microbial diversity and community composition within fresh water rock pools and slot canyons of the Colorado Plateau, Utah. The purpose of the study was to determine the relative importance of various microbial community assembly processes. This thesis also includes a meta-analysis of the microbial alpha diversity in other perennial and ephemeral aquatic …

North Dakota Greater Sage-Grouse (Centrocercus Urophasianus) Recovery Project: Using Translocation To Prevent State-Wide Extirpation And Develop Rangewide Protocols, Kade D. Lazenby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocurcus urophasianus; hereafter sage-grouse) are the largest grouse species in North America. Sage-grouse occupy 11 western states, extending into North Dakota. North Dakota sage-grouse population is part of the Great Plains Management Zone. Conservation of sage-grouse has been on the forefront of conservation management 1990s. In 2015 the USFWS declared sage-grouse were not warranted for listing based on significant management efforts. Translocations of sage-grouse to prevent populations from extirpation are an example of these efforts.

Translocations have been described as movement and release of animals into a novel environment. There have been more than 7200 sage-grouse …