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The End-Permian Mass Extinction And The Siberian Traps Eruptions, Rebecca Teed

Earth and Environmental Sciences Faculty Publications

This handout focuses on the evidence for the theory that a series of flood-basalt eruptions in Siberia caused the mass extinction at the end of the Permian Period. This is the worst mass extinction known to geologists, and 90% or more of all species on Earth were wiped out. It is part of a set of four articles on possible causes of the Permian and Cretaceous mass extinctions that can be used to organize classroom debates or to have students compare and contrast the events and their causes.

Stream Benthic Algal Relationships With Multi-Metric Indices Of Sensitivity, Exposure, And Vulnerability To Watershed Land Use Change, With An Emphasis On Unconventional Natural Gas Development, Hannah J. Verkamp

Biological Sciences Undergraduate Honors Theses

Unconventional natural gas (UNG) is harvested using a unique fossil fuel extraction method that uses horizontal drilling and hydraulic fracturing techniques. The combined methods have expanded the industry both nationally and globally, and development has the ability to transform landscapes and impact freshwater resources. Natural gas wells are often near streams, yet substantial knowledge gaps remain as to how and the extent to which development affects surface waters. Stream algal biomass can respond positively to anthropogenic stressors associated with different types of land use, including agriculture. Benthic algal biomass can also positively correlate with UNG well density and proximity to …

Spatial Ecology And Captive Behavior Of Rehabilitated Black Bears In Utah, Patrick J. Myers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Animal movements and space use are fundamental components of life and play integral roles in organismal fitness, population dynamics, and the ecology and evolution of species. The heterogeneous distribution of resources and the movement required to access them, results in ecology being a fundamentally spatial concept. Thus, elucidating animal-habitat relationships is a central focus of wildlife ecology and conservation. I utilized GPS technology, resource selection functions, and generalized linear mixed models, to investigate the immediate post-release movements, denning chronology, release-site fidelity, and season-delineated movements, home ranges, and resource use for six, orphaned and rehabilitated black bears (Ursus americanus). …

Dietary Effects On The Stoichiometry Of Growth, Regulation, And Wastes Of Ozark Stream Insect Detritivores, Halvor Matthew Halvorson

Graduate Theses and Dissertations

A widespread stressor, anthropogenic nitrogen (N) and phosphorus (P) pollution can increase resource nutrient content and alter animal community composition in freshwater ecosystems. In this dissertation, I used ecological stoichiometry theory to examine effects of diet nutrient content and leaf litter type on growth, regulation, and wastes of aquatic invertebrate detritivores. I tested effects of leaf litter diet carbon:phosphorus (C:P) on growth and stoichiometric regulation of the detritivorous caddisfly Pycnopsyche lepida and used results to determine a threshold elemental ratio of oak litter C:P=1620 that confers peak growth of this species. This empirical, growth-based approach provided a more accurate estimate …

[Re]Visiting The Rime: A Case Study Of Adaptation As Process And Product With The Rime Of The Ancient Mariner, Sally Ferguson

Graduate Theses and Dissertations

This thesis combines adaptation theory with ecology to examine Samuel Taylor Coleridge's Rime of the Ancient Mariner (1798) and its adaptations; it argues further combinations of adaptation with evolutionary theory and ecological ideas could allow for a better interpretation of many texts. The adaptation Rime of the Modern Mariner (2011) by Nick Hayes and the appropriation Perelandra (1943) by C.S. Lewis will also be present in individual chapters to examine the texts' interactions with each other as they evolve and how each work represents the combined theory.

Gaur (Bos Gaurus) Abundance, Distribution, And Habitat Use Patterns In Kuiburi National Park, Southwestern Thailand, Supatcharee Tanasarnpaiboon

School of Natural Resources: Dissertations, Theses, and Student Research

Population status of gaur (Bos gaurus), a wild cattle, in most habitats where they are present, is still unknown. As the use of camera traps in wildlife studies are widespread, I developed photographic individual identification procedures and utilized encounter histories of gaur individuals from camera trap data to estimate gaur abundance and density using the spatially explicit capture-recapture analysis. The study was conducted at Kuiburi National Park, southwestern Thailand, comprised of dry evergreen forest, moist evergreen forest, and man-modified secondary forest during November 2013- January 2015. I conducted 71 direct observations in a savannah-like habitat area to observe …

Estimating The Frequency Of Sexual Reproduction In The Diatom Stephanodiscus Niagarae, Ann W. Dickens

Biological Sciences Undergraduate Honors Theses

Diatoms are single-celled micro-algae with cell walls composed of silica, that reproduce in a way that results in a decrease in cell size after each round of mitotic (asexual) division. A cell cannot continue to shrink indefinitely, so when the average size of the population reaches a critical threshold, diatoms reproduce sexually and restore their maximal size. It is unclear, however, how frequently diatoms undergo sexual reproduction in nature. As a proxy for sexual reproduction, I monitored changes in cell size of a population of the diatom Stephanodiscus niagarae from the plankton community of Lake Fayetteville (Arkansas, USA). Weekly sampling …

Physiology And Genetics Of Starvation-Selected Drosophila Melanogaster, Christopher Michael Hardy

UNLV Theses, Dissertations, Professional Papers, and Capstones

In nature, organisms have evolved to survive in stressful environments. This has driven organisms to adopt a wide range of unique adaptations. Investigating the mechanistic basis of these adaptations is an important tool for discovery that has led to major advances in science and medicine.

We study how organisms survive life without food, or starvational stress. Environmental stressors have shaped the quantity and quality of food sources across the globe. This has led to vast differences in the ability of some organisms to tolerate starvation over others. Many researchers have used Drosophila melanogaster as a model to study global patterns …

Risky Business: Tradeoffs Between Nutrition, Toxicity, And Predation By A Specialist Mammalian Herbivore, Jordan D. Nobler

Boise State University Theses and Dissertations

Animals must balance many risks and rewards when using resources and selecting habitats. Understanding how animals make these choices requires elucidating the functional significance and interactions among habitat features. The criteria an animal uses to determine the functional quality of a resource may differ from those traditionally measured in surveys of habitat quality. Similarly, the relative value of a particular resource may vary with an animal’s physiology or behavior, or the unique combination of the resource’s characteristics. Previous studies have identified a number of specific individual, measurable, habitat parameters that influence habitat selection of a sagebrush specialist, the pygmy rabbit …

Stopover Ecology Of Ruby-Throated Hummingbirds (Archilochus Colubris) During Autumn Migration, Theodore Joseph Zenzal Jr

Dissertations

The Ruby-throated Hummingbird (Archilochus colubris) is one of the smallest Nearctic-Neotropical migrants and the only species of hummingbird that breeds in Eastern North America, yet few studies have investigated the biology of Ruby-throated Hummingbirds when they stopover during migration. Given their small size, high metabolism, aggression, and specialized diet, hummingbirds may represent a migrant that operates on the physiological edge. Therefore it is important to understand the factors that influence their stopover as well as the decision to resume migration. Towards this end, Ruby-throated Hummingbirds were captured during autumn migration along the northern coast of the Gulf of Mexico to …

Depression In Thermal Performance Of Age-Structured Spirodela Polyrhiza Due To The Presence Of Rhopalosiphum Nymphaeae, Mitchell Matis, Chad Brassil, Colby J. Tanner

UCARE: Research Products

Thermal performance curves are keys components of population ecology. We performed this study to determine the effects of aphids on duckweed age-structured models across temperature. Results show a depression in birth rates and maturation of rates of duckweed in the presence of aphids. Regression analysis shows that this depression in maturation and birth is directly proportional to aphid growth rates across temperatures. This hints of the idea of modeling duckweed and aphid growth via nested thermal performance curves.

Ecology And Genetics Of Lungless Salamanders (Family Plethodontidae) In The Gulf Coastal Plain, Jennifer Yasmin Lamb

Dissertations

During the last half century, lungless salamanders (Family Plethodontidae) have been the subject of numerous studies in the fields of ecology and genetics. While most works have focused on the species-rich Eastern Highlands region, there has been a recent shift towards plethodontid assemblages within the Coastal Plain. The research presented herein applies hierarchical occupancy models and both mitochondrial and nuclear genes to address questions pertinent to the biology and conservation of plethodontids within the Gulf Coastal Plain. The results of a multi-species Bayesian single-season occupancy model indicated that two environmental gradients, upstream drainage area and stream drying, influenced the probability …

Greater Bud Outgrowth Of Bromus Inermis Than Pascopyrum Smithii Under Multiple Environmental Conditions, Jacqueline P. Ott, Jack L. Butler, Yuping Rong, Lan Xu

Natural Resource Management Faculty Publications

Tiller recruitment of perennial grasses in mixed-grass prairie primarily occurs from belowground buds. Environmental conditions, such as temperature, soil moisture and grazing can affect bud outgrowth of both invasive and native perennial grasses. Differential bud outgrowth responses of native and invasive species to climate change and grazing could alter competitive interactions that have implications for future land management. The aims of this work were to (i) compare how spring temperature altered bud outgrowth of native Pascopyrum smithii (Rydb.) Á. Löve (western wheatgrass) and introduced Bromus inermis Leyss.(smooth brome), (ii) compare how watering frequency altered bud outgrowth of these two species …

Validation Of The Use Of Doubly Labeled Water For Measuring Metabolic Rate In Timber Rattlesnakes (Crotalus Horridus), Caitlin Hirsh

Biological Sciences Undergraduate Honors Theses

The doubly labeled water method is an isotopic technique for measuring field metabolic rate and water flux rates of free-living animals. We present a validation of the use doubly labeled water for measuring metabolic rate and water loss in Timber Rattlesnakes (Crotalus horridus). For this study seven animals of varying body size were used with masses ranging from 148 to 650 grams. Prior to dosing, blood samples were taken to establish background isotope levels for each animal. Snakes were injected with water enriched with isotopes of oxygen (18O) and hydrogen (2H, deuterium). The injected isotopes were then allowed to equilibrate …

Response Of Leukocyte Profiles To Corticosterone Manipulation In The Prairie Rattlesnake (Crotalus Viridus), Jill E. Guillette

Biological Sciences Undergraduate Honors Theses

Prior work has shown that when animals are stressed they have altered leukocyte profiles. The use of leukocyte profiles could provide an inexpensive and efficient method for determining stress. Here we present a validation of the use of leukocyte profiles for showing induced stress in Prairie Rattlesnakes (Crotalus viridus). Snakes (N=19) with masses ranging from 682g to 137g were used in a repeated measures design to examine the effect of hormone manipulation on leukocyte profiles. During each trial snakes were dosed with either corticosterone and sesame oil (1.1µg/g) or only sesame oil. Prior to dosing, baseline blood samples …

A Preliminary Study On The Role Of Enhancer Of Flavonoid Production (Efp) In Flavonoid Biosynthesis, Jia Guo

Honors Scholar Theses

Flavonoids are involved in a variety of biological roles ranging from pathogen protection, pigment intensity, antioxidant effects, and even prevention from cancer or cardiovascular diseases. Because of the diverse and beneficial functions that flavonoids have, the flavonoid biosynthetic pathway has been well studied. Recently, a gene called the Enhancer of Flavonoid Production (EFP) was discovered when mutations in this gene caused the Japanese morning glory flowers to exhibit a pale-colored phenotype. Although EFP is known to increase flavonoid production, the direct mechanism to how EFP enhances enzymes in the flavonoid biosynthetic pathway has yet to be discovered. It …

Tick-, Mosquito-, And Rodent-Borne Parasite Sampling Designs For The National Ecological Observatory Network [Special Feature: Neon Design], Yuri P. Springer, David Hoekman, Pieter T.J. Johnson, Paul A. Duffy, Rebecca A. Hufft, David T. Barnett, Brian F. Allan, Brian R. Amman, Christopher M. Barker, Roberto Barrera, Charles B. Beard, Lorenza Beati, Mike Begon, Mark S. Blackmore, William E. Bradshaw, Dustin Brisson, Charles H. Calisher, James E. Childs, Maria A. Diuk-Wasser, Richard J. Douglass, Rebecca J. Eisen, Desmond H. Foley, Janet E. Foley, Holly D. Gaff, Scott Lyell Gardner, Howard S. Ginsberg, Gregory E. Glass, Sarah A. Hamer, Mary H. Hayden, Brian Hjelle, Christina M. Holzapfel, Steven A. Juliano, Laura D. Kramer, Amy J. Kuenzi, Shannon L. Ladeau, Todd P. Livdahl, James N. Mills, Chester G. Moore, Serge Morand, Roger S. Nasci, Nicholas H. Ogden, Richard S. Ostfeld, Robert R. Parmenter, Joseph Piesman, William K. Reisen, Harry M. Savage, Daniel E. Sonenshine, Andrea Swet, Michael J. Yabsley

Scott L. Gardner Publications

Parasites and pathogens are increasingly recognized as significant drivers of ecological and evolutionary change in natural ecosystems. Concurrently, transmission of infectious agents among human, livestock, and wildlife populations represents a growing threat to veterinary and human health. In light of these trends and the scarcity of long-term time series data on infection rates among vectors and reservoirs, the National Ecological Observatory Network (NEON) will collect measurements and samples of a suite of tick-, mosquito-, and rodent-borne parasites through a continental-scale surveillance program. Here, we describe the sampling designs for these efforts, highlighting sampling priorities, field and analytical methods, and the …

Fishery And Population Dynamics Of Mississippi’S Spotted Seatrout, David Arthur Dippold

Master's Theses

Spotted Seatrout (Cynoscion nebulosus) is the most popular recreational inshore fishery in Mississippi coastal waters. Because of the popularity of Spotted Seatrout in Mississippi as a recreational target and the magnitude of harvest, quantitative approaches to describe the population and fishery dynamics of the Mississippi stock are needed to continue the sustainability of the stock. Quantitative approaches to describing stock dynamics are useful because they can help describe population characteristics, assess the current status of the stock, and be used to evaluate alternative management strategies. In this thesis, I use a suite of quantitative methods to describe, evaluate, …

Intraspecific Variation In The Response Of Elymus Elymoides To Competition From Bromus Tectorum, Rebecca K. Mann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the western United States, thousands of acres of degraded rangelands are dominated by aggressive invasive species such as cheatgrass (Bromus tectorum), and are seeded by managers with native plants in an attempt to restore species diversity, wildlife habitat, and ecosystem services. There are many options for obtaining seeds of native plants; for instance, they can be collected from the region where restoration is to occur, or they may be purchased through commercial producers. For a given plant species, managers may also select seeds from unique subspecies, cultivars, and populations. Genetic differentiation among these within-species groups can not only affect …

Genetic Variation In Long-Term And Short-Term Physiological Changes In Daphnia Magna During Acclimation To High Temperature, Bret L. Coggins

Undergraduate Honors Theses

The aquatic zooplankton crustacean Daphnia magna must be able to tolerate thermal stress in order to survive their native shallow ponds that are susceptible to drastic seasonal and diurnal temperature fluctuations as well as to globally increasing temperatures. Survival in such variable environments requires plastic responses that must include fundamental aspects of Daphnia biochemistry and physiology. Adaptive response to selection favoring such plastic phenotypes requires the presence of genetic variation for plastic response in natural populations. Adverse effects of elevated temperature on aquatic organisms are diverse and so are their plastic responses; among the most severe challenges aquatic organisms face …

The Joint Effect Of Phenotypic Variation And Temperature On Predator–Prey Interactions, Jean Philippe Gibert

School of Biological Sciences: Dissertations, Theses, and Student Research

Understanding the factors underpinning to food web structure and stability is a long-standing issue in ecology. This is particularly important in a context of global climate change, where rising environmental temperatures may impact the way species interact, potentially leading to changes in food web structure and to secondary extinctions resulting from cascading effects. In order to understand and predict these changes, we need to hone our comprehension on the way predators and their prey interact. Recent studies suggest that, in order to do so, we need to focus on the traits controlling those interactions, such as body size. Mean body …

Using Accelerometer Data To Remotely Assess Predation Activity Of Arctic Wolves, Heather Shipp

Undergraduate Honors Capstone Projects

Arctic wolves (Canis lupus arctos) play an important role in ecosystems located in the far northern regions of the world; however, unlike the gray wolves in Yellowstone National Park, little information is available about High Arctic wolves and their impacts on prey populations. This research uses data received from two GPS radio-collared Arctic wolves located in the Fosheim Peninsula on Ellesmere Island. Each radio-collar was programmed to record a position every 30-60 minutes, as well as the wolfs activity movement (forwards - backwards and left - right), which was generated by an accelerometer housed within the radio-collar. This …

Rapid Savanna Response To Changing Precipitation Intensity, Ryan S. Berry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate change has the potential to cause large-scale changes in plant growth, biodiversity, and biosphere-climate feedbacks. A pervasive aspect of climate change is that as the atmosphere warms, precipitation events are likely to become less frequent but more intense, because warmer air can hold more water. Larger precipitation events can be expected to change plant productivity and community composition, particularly in semiarid ecosystems such as savannas. Savannas are of particular interest because they are spatially expansive at the global scale, they are important to humans for food production, and they are known to be sensitive to changes in soil water …

Control Of Large Stands Of Phragmites Australis In Great Salt Lake, Utah Wetlands, Chad R. Cranney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phragmites (common reed) is a non-native, invasive perennial grass from Eurasia that is taking over wetlands across North America. In Utah, Phragmites has expanded to cover tens of thousands of acres in and around the Great Salt Lake (GSL). The GSL and its associated wetlands are recognized regionally and hemispherically as an important bird area (IBA) that provide critical habitat for a wide variety of wetland dependent birds. The invasion and expansion of Phragmites has replaced many of the high quality habitats these avian populations rely on. This research aimed to determine the most effective methods to control Phragmites and …

Assessing Plant Community Structure In The Upper Las Vegas Wash Conservation Transfer Area, Nevada: The Influence Of Biotic And Abiotic Variables, Amy A. Croft

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecological communities are complex, the structure of which is composed of interactions between multiple community characteristics and the abiotic and biotic factors shaping them. Because of this complexity, ecological studies are generally limited in scope and size, often dissecting communities into their component parts to examine them piece by piece. While this might be the most practical method to study communities, this approach often neglects other characteristics that, with their inclusion, would provide a more complete picture of community ecology. The studies described in this dissertation were conducted in an effort to synthesize the complexity that is inherent in ecological …

Refining Methods For Quantifying Macroinvertebrate Estimates Of Preference For Use In Stream Bioassessments, Ellen F. Wakeley Tomlinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two-thirds of United States stream length is in either fair or poor biological condition. However, we do not yet have reliable, quantitative tools to diagnose site-specific causes of biological impairment. One way to diagnose causes of impairment is to compare the environmental tolerances or preferences of the taxa expected at a site to those of the observed community. Stream ecologists have derived tolerance values (TVs) from field data for use in causal analysis, but inconsistencies across studies cast doubt on the accuracy of these TVs. Published TVs may not agree with one another for several reasons, including: differences in the …

Revegetation Of Bulrushes Bolboschoenus Maritimus, Schoenoplectus Acutus, And S. Americanus In Great Salt Lake Wetlands: Seed Biology And Influence Of Environmental Factors On Rhizomes, James Marty

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A primary goal of ecological restoration is to establish desirable plant species. This goal is particularly important following the removal of invasive plants. Understanding biological characteristics of plant species important to revegetation is crucial to plant establishment. In the globally important Great Salt Lake (GSL) wetlands, native habitat-forming bulrushes Bolboschoenus maritimus, Schoenoplectus acutus, and S. americanus are frequently displaced by the invasive grass Phragmites australis. Bulrush seeds require very specific germination conditions and are also dormant, therefore they do not germinate consistently even when exposed to appropriate germination conditions. Additionally, wetland environments are often associated with water …

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 …

The Utah Forest Dynamics Plot: Long-Term Ecological Monitoring And Theoretical Ecology In A High-Elevation Subalpine Environment, Tucker J. Furniss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Unified Neutral Theory of Biodiversity has been advanced as a universal theory for species coexistence in forests worldwide, but few studies have examined its relevance to high-elevation, stressful environments. I established the Utah Forest Dynamics Plot (UFDP) in a heterogeneous subalpine forest at 3,091 m elevation on the Colorado Plateau to examine three underlying assumptions of neutral theory (functional equivalence, ecological equivalence, and habitat generality) and one prediction (the species abundance distribution). The UFDP comprises 27,845 stems ≥1 cm diameter at breast height of 17 species, 10 genera, and 6 families over 13.6 ha. The neutral model was a …

The Demography And Determinants Of Population Growth In Utah Moose (Alces Alces Shirasi), Joel S. Ruprecht

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Moose (Alces alces) occur widely in northern regions of the world. Across their distribution, the species is considered to be of high intrinsic, ecological and recreational value. Populations of moose along their southern range limit in North America have shown erratic population dynamics in recent decades including severe numeric declines in some areas. Moose in Utah belong to the Shiras subspecies, which is a relatively understudied population segment. Additionally, moose in Utah represent the southernmost naturally occurring moose populations worldwide. Concerns over possible declines and a paucity of baseline data on moose within the state prompted the Utah …