Ecology and Evolutionary Biology Commons^™

Fractally Sampling Diversity-Environment Relationships To Understand Plant Assemblage Health Across Spatial Scales, Elizabeth G. Simpson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humans influence the health of ecosystems and rely on healthy ecosystems to support their livelihoods and well-being. By looking at how the parts of ecosystems interact we can understand and improve ecosystem health. Ecosystem interactions change across spatial scales or different size patches of area. For example, individual organisms interact with each other at small spatial scales, while at large spatial scales, communities of organisms interact with weather conditions. However, many research studies do not look at how ecosystem interactions change across spatial scales. To address this gap in ecological research, I use a fractal sampling design which samples at …

The Effects Of Recent Climate Change On Spring Phenology, With A Special Focus On Patterns Of Bee Foraging, Michael Stemkovski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The date on which plants flower and on which bees begin to pollinate varies year-to-year depending on differences in weather. This seasonal timing is known as phenology, and it is already clear that climate change has pushed the spring phenology of many species earlier by increasing temperatures. This is particularly clear in flowering plants, but studying how and why the phenology of pollinators is shifting is more difficult. Most flowering plants rely on pollinators such as bees for their reproduction, and most bees rely on flowers for their sustenance, so bee and flower phenology has to overlap for the crucial …

Avian Species Distribution Models: Using Location Data To Inform Management Decisions, Marilyn E. Wright

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Both state and federal wildlife agencies strive to conserve and protect wildlife and their habitats as an important public resource. Applied management decisions often rely on being able to obtain data that can efficiently and effectively enhance the understanding of these systems for informing management actions. Wildlife managers often focus efforts on a small subset of species from an ecosystem, typically called focal species, who can serve as surrogates for understanding the health and function of the system. Models that consider how these focal species interact with the ecosystem are often used to better understand important aspects of their life …

Immunological Tradeoffs And The Impacts Of Urbanization On The Reproductive Ecology And Physiology Of The Side-Blotched Lizard (Uta Stansburiana), Emily E. Virgin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investing resources into reproduction can limit energy available to other competing demands, such as fighting off an infection; yet, both processes are necessary for organisms to survive and pass on their genes to the next generation. These strategies often follow patterns associated with lifespan, such that shorter-lived animals are more likely to invest more resources into reproduction over survival, and vice versa in long-lived animals. However, environmental change caused by urbanization can disrupt these relationships, and the within- and transgenerational costs of urbanization on females and offspring are unknown. I address these uncertainties in three research chapters to better understand …

Evolution Of Floral Microbes And The Resulting Effects On Pollinator Preference, Hailey Hatch

Undergraduate Honors Capstone Projects

Floral microbes are an overlooked aspect of the extended floral phenotype. Through altering floral nectar chemistry, they can mediate interactions between flowers, pollinators, and other floral microbes, with significant implications for plant and pollinator health. Interactions between floral microbes and pollinators are critically important to understand, as pollinators provide important ecosystem services in both natural and agriculture systems. Here, I explored how floral nectar traits affected both evolution and competition within the floral yeast Metschnikowia reukaufii, the floral bacterium Bacillus subtilis, and other microbes isolated from Brassica rapa nectar, an important plant model system and oilseed crop. To …

Global Change Effects On Carbon Cycling In Terrestrial Ecosystems, Guopeng Liang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since terrestrial ecosystems store approximately 3 times more carbon (C) than the atmosphere, they have a significant effect on the atmospheric CO₂ concentration. Although many studies have been conducted to determine global change effects on C cycling in terrestrial ecosystems, the underlying mechanisms remain uncertain. To address this knowledge gap, I utilized meta-analysis, laboratory experiments, and soil microbial community analysis.

In chapter 2, I conducted a meta-analysis to examine whether effects of long-term N addition on plant productivity can shift over time. I found that 44% of studies showed a marked trend (increase or decrease) in the strength of …

Greater Sage-Grouse And Community Responses To Strategies To Mitigate Environmental Resistance In An Anthropogenic Altered Sagebrush Landscape, Justin R. Small

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sagebrush (Artemisia spp.) ecosystems are diverse habitats found throughout western North America. Anthropogenic disturbances has resulted in the loss of over half of the sagebrush ecosystems impacting sagebrush obligate species such as sage-grouse (Centrocercus spp.). Federal, state, and private land managers have implemented landscape scale mechanical pinyon (Pinus spp.) and juniper (Juniperus spp.; conifer) removal projects in an effort to restore functioning sagebrush communities to benefit sage-grouse. However, few studies have investigated the potential for using large-scale conifer treatments to mitigate factors impeding sage-grouse seasonal movements and space-use in anthropogenic altered landscapes.

To address this management need, I …

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 …

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 …

Bridging Post-Wildfire Communication Gaps Between Managers, Researchers, And Local Communities, Including A Biological Soil Crust Case Study, Hilary Louise Whitcomb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Immediately after a wildfire land managers act quickly to protect water supplies, soil stability, habitat, and forage. We don't currently understand how managers make trade-off decisions between social, political, and ecological factors in these tight timelines or if they are able to use new science. We do know ecosystems often benefit from local engagement, and new, scientifically-grounded methods that improve restoration efforts are needed. As post-wildfire timelines don’t often allow for outside input, I asked managers what they and stakeholders think about post-wildfire projects and what managers think about new science. I asked local citizens what they think about postwildfire …

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 …

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. …

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 …

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 …

The Status Of Dwarfed Populations Of Short-Horned Lizards (Phrynosoma Hernandesi) And Great Plains Toads (Anaxyrus Cognatus) In The San Luis Valley, Colorado, Megan E. Lahti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The San Luis Valley is a large valley formation in Colorado surrounded on either side by mountain ranges exceeding 4,267 m. Within the Valley, two of the 14 amphibian and reptile species are dwarfed: the short-horned lizard (Phrynosoma hernandesi) and the Great Plains toad (Anaxyrus cognatus). Since its initial reporting in 1968 and confirmation in 1981, no research further investigating this dwarfism has been conducted. I collected morphological measurements to determine the extent and patterns of dwarfism of both species. I then investigated the genetics of both species using mitochondrial DNA to determine whether they are …

Reproductive Tactics Of Aphidophagous Lady Beetles: Comparison Of A Native Species And An Invasive Species That Is Displacing It, Yukie Kajita

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coccinella septempunctata L. (Coleoptera: Coccinellidae) has been introduced to North America in recent decades, raising concerns of adverse impacts on native lady beetles, including the congeneric C. transversoguttata richardsoni (Brown). The central focus of my dissertation is to understand the importance of reproduction, in particular, in promoting invasion of C. septempunctata and its replacement of native lady beetles in alfalfa fields of western North America.

Studies were conducted to compare reproductive tactics of the invasive C. septempunctata and the native C. transversoguttata, by addressing: 1) maximum rate of reproduction of overwintered lady beetles, 2) population dynamics of the invasive …

Predator-Prey Relationships And Spatial Ecology Of Jaguars In The Southern Pantanal, Brazil: Implications For Conservation And Management, Sandra Maria Cintra Cavalcanti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Pantanal wetland of Brazil is an important area for the conservation of jaguars (Panthera onca) and a stronghold for the species. Although our knowledge of jaguar ecology has increased since the first field studies in the mid 1980’s, a detailed study of this cryptic species remains challenging. In the following chapters, we investigated the ecology of jaguars in the southern Pantanal of Brazil. In Chapter II, we examined the foraging ecology of jaguars, documenting predation rates, patterns, and species killed. We found individual jaguars differed in the selection of their prey. There were differences in the proportion …

Conservation Implications Of Winter-Feeding Policies For Mule Deer In Utah, Chris C. Peterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Policies regulating wildlife winter-feeding programs may have long-term impacts on conservation and future management of both target and non-target species. In 2000, the Utah Wildlife Board, upon reviewing input from a series of public regional meetings, adopted a Utah Big Game Winter-Feeding Policy. The Utah Division of Wildlife Resources used this policy to regulate winter-feeding programs for mule deer in northern Utah, 2001-2005. I monitored the program effects on mule deer biology, activity and migration, and winter browse utilization and productivity.

While feed rations generally compensated for protein and energy deficiencies, they may overlook mineral deficiencies. To determine if mule …

An Investigation Of The Early Life-History Of Brown Trout (Salmo Trutta) And Potential Influences On Invasion Success In The Logan River, Utah, Jeremiah Wood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to the significant threats posed by nonnative fish species worldwide, it is important to understand how life-history strategies of individual species interact with environmental conditions to explain the success or failure of nonnative fish invasions. Brown trout are prolific invaders, but often exhibit upstream distributional limits in Intermountain West streams, potentially due to a maladaptive reproductive life-history strategy influenced by hydrologic conditions in high-elevation areas. We used redd counts, egg survival experiments, and temperature modeling to investigate the reproductive life-history strategy of brown trout and its potential for success along an elevational stream gradient. We documented brown trout spawning …

Granivores And Restoration: Implications Of Invasion And Considerations Of Context-Dependent Seed Removal, Steven M. Ostoja

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Granivores are important components of sagebrush communities in western North America. These same regions are being altered by the invasion of the exotic annual Bromus tectorum (cheatgrass) that alters physical and biological dynamics in ways that appear to promote its persistence. This research directly relates to the restoration of B. tectorum-dominated systems in two inter-related ways. First, because these landscapes have large quantities of seeds applied during restoration, it is important to determine the major granivore communities in intact sagebrush communities and in nearby cheatgrass-dominated communities. Second, it is important to develop an understanding of patterns of seed harvest …

The Reproductive Biology And Edaphic Characteristics Of A Rare, Gynodioecious Saxifage: Saxifraga Bryophora Var. Tobiasiae (Saxifragaceae), Kimberly Pierson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I examined the reproductive biology and general ecology of Saxifraga bryophora var. tobiasiae, a rare saxifrage endemic to the West Salmon River Mountains of central Idaho. Saxifraga bryophora var. tobiasiae combines asexual reproduction via bulbils with a sexual mixed-mating system. Flower production occurred in 1996 only, whereas bulbil production occurred in 1995, 1996, and 1997. Bulbil production precedes floral bud formation and is the dominant form of reproduction. When flowering occurs, outcrossing is promoted by protandry and the gynodioecious mating system found in all populations. No autogamous or agamospermous seed set was observed in either female or hermaphrodite flowers, …

Growth Of Phytophthora Infestans Race 1.2.4 And Synthesis Of Steroid Glycoalkaloids By The Fungus In Synthetic Media, Melanie R. Maas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A chemically defined synthetic medium was developed in which Phytophthora infestans (Mont.) de Bary race 1.2.4 grew extensively. This medium consisted of: 90.0 grams maltose, 20.0 grams DL-alanine, 20.0 grams L-proline, 1.0 gram KNO₃, 0.5 gram KH₂PO₄, 0.25 gram MgSO_4. 7H₂O, 1.0 milligram thiamin per liter of distilled water. The average level of growth in this medium was 0.5864 gram dry weight mycelium per 50 milliliters medium.

The glycoalkaloids, solanidine and solanine, were synthesized by Phytophthora infestans in the above medium with 62.5 percent of the samples positive and an overall …

The Role Of Vegetation Architecture In Determining Spider Community Organization, Cynthia L. Hatley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The relationships between vegetation architecture and spider community attributes were examined in a big sage (Artemisia tridentata) community. Spiders were separated into guilds using similarities of species' hunting behavior. Shrub architecture was experimentally manipulated in the field by either clipping 50% of a shrub's foliage to decrease foliage density or tying together a shrub's branches to increase foliage density.

Temporal patterns of spider species density, diversity (H') and evenness (J') showed midsummer peaks in both 1974 and 1975. Seasonal spider guild trends reflected the temporal prominence of a member species or genus. These temporally abundant species appeared to …

Drift Of Oligophlebodes Sigma And Baetis Bicaudatus In A Mountain Stream, William Dean Pearson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of this study was to clarify the relationships between drift rates, population density, production rates, key environmental factors, and movements of adults within two populations of stream insects (a caddisfly--Oligophlebodes sigma and a mayfly--Baetis bicaudatus).

Samples of benthic invertebrates (424 total) were collected every 28 days at four stations on Temple Fork of the Logan River, Utah, from October, 1967 to September, 1969. Samples of drift invertebrates (181 total) were collected every 14 days at three stations on Temple Fork during the same period. During summer months (June-September) a day and a night drift sample …

Effects Of Starvation And Time At Stocking On Survival Of Stocked Rainbow Trout, Salmo Gairdneri, Marlin John Bricker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investigations of effects of starvation and time at stocking on the survival of catchable rainbow trout in two areas of Mammoth Creek in Dixie National Forest, Utah, were conducted from May 24 to December 6, 1969. Fish were starved for 6 days and 1 day and stocked in the morning (5:40-7:00 a.m.) and in the afternoon (1:45-5:30 p.m.). Out of 7,000 tagged fish stocked, 4,751 tags were returned by fishermen. The 6-day starved fish, stocked in the morning returned to the creel in highest numbers (1,240); followed by 1-day starved, afternoon-stocked fish (1,194); 6-day starved, afternoon-stocked fish (1,163); and 1-day …

Canada Goose Production And Population Stability, Ogden Bay Waterfowl Management Area, Utah, Norman H. Dey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since the development of Ogden Bay Waterfowl Management Area in 1937, the Canada goose (Branta canadesis moffitti) population increased to a peak in 1949 and then declined slightly. Nelson (1954) noted that the decrease in population was probably due to either a change in habitat or increased hunting pressure. In recent years, direct band returns have indicated a high mortality rate in the population. This project was initiated to determine the relative stability of the Canada goose population and to measure, as closely as possible, the effect of a high mortality rate upon the nesting population.

To estimate …

Actinomycetes Of Virgin Utah Soils With Special Reference To Antagonisms, Paul H. Krumperman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The importance of actinomycetes in the soils was generally overlooked until about 1913. The investigators Hiltner and Stormer and Beijerinck began systemtaic study of their occurrence and role in soil fertility. The work done by these men and others since 1913 has proved actinomycetes to occur abundantly in most soils of the world. This work done by these men and others since 1913 has proved actinomycetes to occur abundantly in most soils of the world. This work has also proved the function of these organisms to be that of decomposing highly resistant materials such as humus and complex polysaccharide compounds. …

Leafhoppers (Cicadellidae) Associated With The Stone Fruit Orchards Of Northern Utah, Mervin W. Nielson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Virus diseases of stone fruit orchards have existed in Utah for more than a quarter of a century and are seriously diminishing the peach and cherry fruit production. Western X of peach, rusty mottle of cherry, wilt and decline of cherry, and little cherry constitute the most economically important stone fruit virus diseases in Utah. Many orchards, particularly in Davis County, have 50 to 83 percent of the trees infected with one or more of the yellow-red viroses. Surveys have shown that the diseases are spreading from 3 to 5 percent each year. It is believed that certain insects are …