Biology Commons^™

Herbivory Changes Soil Microbial Communities And Greenhouse Gas Fluxes In High-Latitude Wetlands, Karen M. Foley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Herbivory by migratory animals in high-latitude ecosystems is known to impact greenhouse gas emissions from soils. However, few studies quantify the relationships between changes herbivores make to plant communities and soil conditions, and the biological interactions soil organisms have with their environment that result in changes to greenhouse gas emissions. These relationships are important to understand because they capture important carbon-climate feedbacks that may have implications for climate change policy and land management decisions, especially since high-latitude systems are experiencing unprecedented changes in climate.

In the Yukon-Kuskokwim (Y-K) Delta in western Alaska, herbivory by migratory geese affects the magnitude of …

Investigating The Roles Of Bacterial Endosymbionts In The Evolution Of Adelgidae (Hemiptera: Sternorrhyncha), Kathryn M. Weglarz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Insects form close partnerships, or symbioses, with bacteria. These partnerships allow the insects to use resources that would be unavailable to them otherwise. Certain insects, hemipterans, are able to feed on nutrient-poor plant-sap because these bacteria supplement their diets. While this association is beneficial for both the insect and bacteria, it also comes with consequences: the genomes of bacterial symbionts typically undergo extreme degradation, becoming small and lacking many genes necessary for typical bacterial functioning. In the Hemiptera, aphids, mealybugs, cicadas, true bugs, and their relatives, these bacterial partnerships tend to be stable over millions of years. However, adelgids (Aphidoidea: …

Exploring The Physiology And Evolution Of Hornworts, Tanner A. Robison

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants contain organelles called chloroplasts, which is where photosynthesis takes place. Chloroplasts also contain their own DNA, which is separate from the DNA in the nucleus. This DNA does not change much over evolutionary time, so it can be used to investigate relationships between organisms. Here we created a tool that makes it easier to analyze this chloroplast DNA as well making it easier to share complete chloroplast genomes on public databases. In addition, we also found a mobile element in the chloroplast DNA of a group of ferns, which appears to be driving structural changes in their genomes.

Quantifying The Predictability Of Evolution At The Genomic Level In Lycaeides Butterflies, Samridhi Chaturvedi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Stephen Jay Gould, a great scientist and evolutionary biologists, suggested that if we could replay the tape of life, we would not have observed similar course of events because evolution is stochastic and if affected by several events. Since then, the possibility that evolution is repeatable or predictable has been debated. Studies using large-scale evolution experiments, long-term data for individual populations, and controlled experiments in nature, have demonstrated phenotypic and genetic convergence in several taxa. These studies suggest that despite some randomness, predictable evolutionary patterns can emerge on a large temporal and spatial scale. However, a few cases also exist …

Eared Grebe Nesting Ecology And Chronology Along The Great Salt Lake, Utah, Leah M. Delahoussaye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Eared Grebes (Podiceps nigricollis) are migratory birds that build their nests over water and in large groups called colonies. Their typical breeding range is in central southern Canada and northern United States; however, a previously uncertain number of Eared Grebes (grebes) also nest around the Great Salt Lake (GSL), Utah, at the southern edge of their breeding range. Little is known about the habitat requirements for grebe nesting colonies at such low latitudes and if they are different from colonies found elsewhere. My objectives for this research were to determine the status of the grebe nesting population as …

Landscape Of Stress: Does Drought Prevail Over Anthropogenic Activity In Influencing Cortisol Levels And Fitness In The Pacific Fisher?, Jennifer R. Kordosky

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fishers (Pekania pennanti) are a species of concern in the Sierra Nevada Mountains of California. Cortisol is a glucocorticoid hormone released to mobilize energy in response to stress and has been used as an indication of an individual’s physiological response to its environment. By collecting samples of fisher hair and measuring an individual’s cortisol, we examined the physiological stress response of the animals to human disturbances (housing density, road density, habitat type, and silvicultural treatements) and drought (tree mortality) in their home ranges. Using AICc model selection, we found that levels of tree mortality within a fisher’s home …

Blue And Red Light Effects On Stomatal Oscillations, Trevor R. Ballard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants absorb CO₂ through pores in their leaves called stomata, which are known to open and close in response to myriad environmental and physiological triggers. We demonstrate that blue light inhibits stomatal aperture oscillations in both the guard cells and surrounding tissue layers, whereas these oscillations continue under the influence of red light. This observation of blue light behavior agrees with recent research and suggests another physiological pathway for oscillations.

Comparative Pollination Efficacies Of Bees On Raspberry And The Management Of Osmia Lignaria For Late Blooming Crops, Corey J. Andrikopoulos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Unlike other rosaceous fruit crops such as apple and cherry, commercial raspberry cultivars are largely self-fertile and can set fruit in the absence of pollinators. However, their floral morphology often prevents complete self-pollaintion. Incomplete pollination yields unmarketable small or crumbly fruits. Insect visitation is therefore essential to maximizing raspberry yield. Honey bees are typically used to pollinate commercial raspberry; however, escalating prices for hive rentals coupled with increasing acreage encourage evaluation of other manageable pollinators. Bumble bees (Bombus spp.) and several mason bees (Osmia spp.) are promising raspberry pollinators. Five bee species were evaluated and compared for their …

Enhancing Spider-Silk Protein Materials Through Continuous Electrospinning And Photo-Initiated Cross-Linking, Dan Gil

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spider-silk is known as one of the stronger natural materials, unfortunately it is impossible to farm spiders due to their territorial and cannibalistic nature. To address this issue, researchers have studied spider-silk to discover how it is produced in nature. From their results, spider-silk is composed of large sized proteins produced in two different cell types. Using this knowledge, researchers created transgenic organisms capable of producing spider-silk proteins in large quantities. Using these proteins, several groups have created fibers, films, hydrogels, and adhesives with robust and versatile properties.

Wet-spinning is a technique commonly used to create fibers from spider-silk proteins. …

Characterization Of Black Walnut Genotypes For Resistance To Thousand Cankers Disease, Frost Hardiness And Other Desirable Horticultural Traits, J. Elisa Lauritzen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The black walnut, Juglans nigra L., is native to the United States (USA) and is a valuable timber and nut tree. Just before the beginning of the 21st century, several western states observed a decline in the health and, later, death of black walnut trees. The pathogen-vector complex now known as thousand cankers disease (TCD) was shown to be the cause. The disease, caused by Geosmithia morbida Kolařik, is vectored by the walnut twig beetle (WTB), Pityophthorus juglandis Blackman. Thousands of WTB will swarm and enter a tree vectoring the fungus at each entry point where cankers then develop, quickly …

Breeding Season Ecology And Demography Of Lesser Scaup (Aythya Affinis) At Red Rock Lakes National Wildlife Refuge, Jeffrey M. Warren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It is hypothesized that individuals make reproductive decisions based on current assessments of their physiological condition and environmental conditions. For female lesser scaup (Aythya affinis), breeding occurs after an energetically costly spring migration. Increasing fat reserves (i.e., ‘body condition’) prior to breeding allows a female to produce a larger clutch of eggs, but time spent gaining body condition is costly in terms of time allowed to raise ducklings before freezing conditions in the fall. In Chapter 2 I explored rate of pre-breeding body condition gain in female lesser scaup, and how that rate influenced clutch size. Spring phenology, …

Historical Biogeography And Natural History Of Nocturnal Wasps In The Southwestern Deserts With Special Emphasis On The Genus Chyphotes (Hymenoptera: Chyphotidae), Emily A. Sadler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Deserts are interesting places due to the large number of plants and animals that live there. Nocturnal wasps are extremely abundant in deserts, but they are difficult to identify and their life cycles are not well known especially the families of Chyphotidae, Tiphiidae (Brachycistidinae), and Mutillidae (velvet ants). In this dissertation, I determine how to correctly identify a particularly difficult group of species that all have black heads from the family Chyphotidae. This is important because these species make up a large proportion of specimens collected. Also, I expanded our knowledge on the distribution of the species of these three …

Phenology Of A Southern Population Of Mountain Pine Beetle (Dendroctonus Ponderosae), Anne Elise Mcmanis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mountain pine beetle (Dendroctonus ponderosae, Hopkins) is a major disturbance agent in pine ecosystems of western North America. Adaptation to local climates has resulted in primarily univoltine (one generation per year) generation timing across a thermally diverse latitudinal gradient. We hypothesized that this pattern in total development time is shaped by selection for slower developmental rates, altered developmental thresholds, or oviposition rates in southern populations inhabiting warmer climates. To investigate traits responsible for latitudinal differences we measured lifestage-specific development of southern mountain pine beetle eggs, larvae and pupae across a range of temperatures. We also describe and model …

Genetic Differentiation Of Two Species Of Buckwheat (Eriogonum), Jenessa Blotter Lemon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Limestone mining in the San Franicso Mountain Range of west central Utah threatens the survival of a rare endemic species of buckwheat (Eriogonum soredium). This species is an edaphic endemic, only found growing on the outcrops of the Ordovician limestone mines in the area. Eriogonum soredium is a candidate for governmental protection under the Endangered Species Act (ESA). However, a common, widespread buckwheat (Eriogonum shockleyi) appears to be closely related to the narrow endemic. The genetic relatedness of the rare and and common species will greatly influence the decision of United States Fish and Wildlife Service …

Ecology Of Greater Sage-Grouse Inhabiting The Southern Portion Of The Rich-Morgan-Summit Sage-Grouse Management Area, M. Brandon Flack

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are sagebrush obligates and are therefore considered to be key indicators of sagebrush ecosystem health. Sage-grouse populations have declined range-wide over the last century due to loss and fragmentation of sagebrush (Artemisia spp.) habitats. Sage-grouse populations found in large intact sagebrush landscapes are considered to be more resilient, however, some small isolated populations persist and thrive in fragmented landscapes. Because of Utah’s unique topography and geography, sage-grouse habitat is discontinuous and populations are naturally dispersed throughout the state in suitable intact blocks or in disconnected islands of sagebrush habitat. Thus, Utah populations …

The Biogeography And Nesting Biology Of Anthophora, With A Revision And Phylogeny Of The Anthophora (Micranthophora), Michael C. Orr

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bees are necessary pollinators for a vast array of different plants, including many which we rely on for food. In order to grow sufficient crops to feed the world’s growing population, we need to make sure our crops are visited by the most effective possible pollinators. However, this is complicated by the fact that there are over 4,000 bee species in North America, many of which vary in their pollination effectiveness and are difficult to identify. My dissertation’s first two data chapters focus on classifying the species of the xeric solitary bee group Anthophora subgenus Micranthophora, including seven newly …

Seasonal Distribution Of Sage-Grouse In Hamlin Valley, Utah And The Effect Of Fences On Grouse And Avian Predators, Heather Hedden Mcpherron

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) numbers have declined throughout the western US and are considered a species of concern in most of the eleven states that are within their range. Sage-grouse habitats have been reduced by approximately 44% since European settlement of the Western United States began (Miller et al. 2011). Loss of habitat has contributed to an average decline of sage-grouse populations by 33% across the range (Connelly and Braun 1997). To expand our knowledge of this species, I monitored 16 radio-collared sage-grouse captured from four leks in Hamlin Valley, Utah, USA in 2011 and 2012 …

Understanding The Biology Of Clover Root Curculio And Improving Their Management Using Biofumigation In Alfalfa, Steven J. Price

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Clover root curculio (CRC) is a pest of alfalfa where larvae feed belowground damaging alfalfa roots. Regional knowledge of CRC activity and biology is limited making the development of pest management strategies difficult. One potential management technique for soil-dwelling pests is the use of biofumigant containing cover crops. Biofumigation can affect the survival and behavior of pest insects. However, biofumigant crops have not been evaluated against CRC or as a rotational crop compatible with alfalfa. The goals of this research were to determine 1) phenology, population sizes, and root damage severity of CRC occurring in the Intermountain region and 2) …

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 …

Seasonal Development Of The Biological Control Agent Of Dalmatian Toadflax, Mecinus Janthiniformis (Curculionidae: Coleoptera), In Utah: Phenology, Overwintering Success, And Mortality, Samantha A. Willden

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

By outcompeting desirable vegetation, invasive weeds can dominate field crops and rangelands, drastically reducing yield and land value. One option in controlling the impact and spread of such weeds is reuniting them with their natural insect herbivores, a process called biological control. When successful, biocontrol can be the cheapest way to provide long-term control of invasive weeds, but continual monitoring of insect and weed activity is required to ensure success.

Dalmatian toadflax is an invasive weed that occurs widely throughout the northwestern U.S., and that is spreading south each year to warmer and drier regions, including sites in Utah. Although …

Using Silkworms As A Host To Spin Spider Silk-Like Fibers, Xiaoli Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Using silkworms as the potential host to spin spider silk-like fibers is an area of intense research world-wide. The conventional methods used to create transgenic silkworms hosting spider silk-like gene limits the incorporation of spider silk-like protein and do not improve the mechanical performance of the composite silkworm/spider silk fibers. In this dissertation, synthetic spider ampullate genes were incorporated into the precise site of the fibroin heavy chain or light chain using the latest genome editing technology CRISPR/cas9 guided non-homologous end joining as opposed to conventional random integration using transposon-based piggyBac system. These protocols, with extensive applicability to other silkworm …

Comparison Of Chikungunya Virus Strains In Disease Severity And Susceptibility To T-705 (Favipiravir), In Vitro And In Vivo, Makda Gebre

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Chikungunya is a mosquito-transmitted disease caused by Chikungunya virus (CHIKV). Symptoms of Chikungunya include debilitating joint pain and swelling, fever and rash. CHIKV was first discovered in 1953 in Tanzania, and has since caused periodic outbreaks of disease. The virus reemerged recently in 2004 and has since spread around the world affecting more than 3 million people. The different strains of CHIKV have been grouped into three phylogenetic clades: West African, Asian and East/Central/South African (ECSA). There are no FDA approved medicines or vaccines used to treat or prevent CHIKV infection. The antiviral drug, T-705 (commercially known as Favipiravir), has …

The Role Of The Fatty Acid Signaling Pathway In Dietary-Induced Obesity, Melissa N. Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years, dietary fat has been shown to be capable of activing taste receptor cells in the tongue. Fatty acids (FAs), which act as the chemical cue and are found in dietary fat, activate a cellular signaling pathway that results in a unique signal being sent to the brain that is then interpreted as the taste of fat. One important element in this pathway is the ion channel TrpM5. It is responsible for depolarizing the taste cells that are activated by fatty acids; depolarization is an essential step in cellular response, making TrpM5 essential in the functioning of the …

Molecular And Physiological Mechanisms Of Toxin Resistance In Toad-Eating Snakes, Shabnam Mohammadi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many plants and animals are defended by toxic compounds, and circumvention of those defenses often has involved the evolution of elaborate mechanisms for tolerance or resistance of the toxins. Toads synthesize potent cardiotonic steroids known as bufadienolides (BDs) from cholesterol and store those toxins in high concentrations in their cutaneous glands. Those toxins protect toads from the majority of predators, including most snakes that readily consume other species of frogs. BDs exert their effect by inhibiting ion transport by the Na⁺/K⁺-ATPase (NKA). This ubiquitous transmembrane enzyme consists of a catalytic alpha-subunit, which carries out the enzyme's …

The Influence Of Wind Energy Development On Columbian Sharp-Tailed Grouse (Tympanuchus Phasianellus Columbianus) Breeding Season Ecology In Eastern Idaho, Matthew C. Proett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus; CSTG) has experienced range-wide population declines, primarily as a result of habitat loss or degradation, and currently occupies <10% of its historic range. Expansion of wind energy developments across the remaining occupied CSTG range has been identified as a potential threat to the species. To assess the potential influence of wind energy development of CSTG breeding season ecology, I captured and radio-marked 135 female CSTG drugin 2014-2015 at leks located between 0.1-13.8 km from wind turbines in restored grassland habitats. Using radio-telemetry, I monitored 147 nests and 68 broods and developed models to assess the influence of wind turbines, roads, habitat features temporal factors, and precipitation on CSTG nest site selection, nest survival, brood success, and chick survival. Female CSTG in my study selected nest sites in grassland habitats where >30% of the canopy cover in the nesting core use area was composed of forbs (i.e., broadleaf plants). The strength of selection for this habitat type increased as its availability increased on the landscape. Nest survival increased with higher visual obstruction readings (i.e., concealment) at the nest bowl and in grassland habitats where forb cover exceeded 30% in the nesting core use area. I did not detect an influence of wind turbines or …

Interactions Between Plant Water-Stress And Neonicotinoid Insecticides On Spider Mite Infestations In Corn, Alice Ruckert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spider mites (Acari: Tetranychidae) are an important agricultural pest of many crops and landscape plants. They can reproduce rapidly and quickly develop resistance to many pesticides, making them difficult to manage. Plant water-stress and high temperatures promote spider mite infestations, while spider mite outbreaks can also result from neonicotinoid insecticide applications. Drought is predicted to increase in the Intermountain West due to increases in temperature and reduced frequency of precipitation events in the region, and neonicotinoids are currently one of the most widely used classes of insecticides in field crops. I studied the interactive effect of these two simultaneously occurring …

Stable Isotopes And The Ecology And Physiology Of Reptiles, Andrew M. Durso

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When animals don’t have enough food, they have to “choose” between “spending” their limited energy on themselves or on their offspring. Biologists think that reptiles can make this choice quickly in response to different environments. But, it can be hard to study these choices because it is hard to convert between, for example, the number of eggs laid and the speed of healing a wound. By using stable isotope chemistry, we can collect more detailed and comparable information about how lizards and other animals spend their limited resources than with any other method. For example, lizards in the wild have …

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 …

Greater Sage-Grouse Vital Rate And Habitat Use Response To Landscape Scale Habitat Manipulations And Vegetation Micro-Sites In Northwestern Utah, Charles P. Sandford

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The greater sage-grouse (Centrocercus urophasianus; sage-grouse) has been a species of conservation concern since the early 20^th century. The decline of populations has largely been attributed to loss and degradation of sagebrush (Artemisia spp.) habitats. To contribute to the knowledge of sage-grouse ecology and quantify the effectiveness of landscape scale habitat manipulations intended to benefit sage-grouse, I monitored habitat use and vital-rates (i.e., nest and brood success) of 45 sage-grouse females in the Box Ender Sage-Grouse Management Area (SGMA) in northwestern Utah. Using telemetry locations of sage-grouse females with known nest and brood fates, I generated …

Biodiversity, Community Dynamics, And Novel Foraging Behaviors Of A Rich Native Bee Fauna Across Habitats At Pinnacles National Park, California, Joan M. Meiners

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Global concern about honeybee declines has spurred feverish research about the status and protection of this single species, yet our understanding of the ecology and issues impacting thousands of species of native bees lags behind. Pinnacles National Park, America's newest, near Salinas, California, is currently the most densely biodiverse area for native bees known on the planet. Recent work by researchers at Utah State University and the USDA-ARS has documented 479 species of native bees in only 42 square miles of this park. During two years of field studies and 308 collector days, we assembled data on 52,853 bee specimens …