Ecology and Evolutionary Biology Commons^™

Habitat And Demography Of The Ozark Chinquapin (Castanea Ozarkensis) At Roaring River State Park In Barry County, Missouri, Danielle Evilsizor

Electronic Theses & Dissertations

The Ozark chinquapin, Castanea ozarkensis Ashe, is a chestnut tree with a range concentrated in the Interior Highlands of North America. Like other North American members of Castanea, it was reduced from an overstory tree to an understory shrub by the invasive chestnut blight fungus (Cryphonectria parasitica [Murrill] M.E. Barr) during the early 20^th century. However, relatively little is known about the habitat of this species or its health and reproductive capability post chestnut blight. Chapter one of this study analyzed the habitat of this species through a random forest species distribution model (SDM) to predict where …

Investigating The Soil Mycobiome Of American Ginseng, Rachel Amelia Rajsp

Electronic Thesis and Dissertation Repository

American ginseng (Panax quinquefolius L.) is a perennial herbaceous plant cultivated for its medicinal properties. Growers report that when ginseng is replanted in a field previously used to cultivate ginseng, it soon succumbs to disease, known as ginseng replant disease. I examined changes in composition in the ginseng mycobiome throughout cultivation in a newly planted garden and beyond (i.e., 3–14 years post-harvest) with a third-generation metabarcoding approach (Pacific Biosciences, single-molecule real-time sequencing). Amplicons of about 600 nucleotides from the nuclear ribosomal internal transcribed spacer (ITS) region and translation elongation factor 1-α gene were chosen to help discriminate between closely …

Psammocora Stellata Distribution At Devil's Crown, Floreana Island, Galápagos Islands, Ecuador, María José Guarderas Sevilla

All HCAS Student Capstones, Theses, and Dissertations

In the Galápagos Archipelago, the free-living nodular coral Psammocora stellata is a common species that does not form reef structures. However, it is a key component of the ecosystem by increasing habitat complexity and, consequently, species diversity. This species experienced a drastic decline in Devil’s Crown channel, Floreana Island, where it disappeared after the 1982-83 El Niño-Southern Oscillation, presumably by displacement of unattached colonies by strong surface waves and currents. This assemblage has now recovered to pre-impact levels. A combination of underwater photoquadrats from 2007 and 2009 and recent (2023) orthomosaics were used to determine changes in coral densities and …

Impacts Of Environmental Stressors On Native South Dakota Amphibian Physiology And Survival, Danielle Jean Galvin

Dissertations and Theses

Amphibian populations around the world are declining, with some of the most likely drivers behind these declines including emerging infectious diseases and environmental contaminants. To address major gaps in the current literature, I sought to evaluate the effect of two major environmental stressors on various aspects of amphibian physiology: emerging infectious diseases and environmental contaminants. Emerging infectious diseases of amphibians include fungal, viral, and parasitic pathogens which have expanded in host range, either geographically or in competent host species. Environmental contaminants include chemicals which may be naturally occurring in the environment, or which may be introduced to the environment, often …

Lizard Communities In A Shifting Landscape: The Current State Of Insectivorous Lizard Communities In The Jornada Basin Between Grassland, Mesquite Dune, And Creosote Bush Habitats In A Semi-Arid Landscape Undergoing Shrubification, Julie Marie Schlichte

Open Access Theses & Dissertations

Lizard communities in arid lands can act as model systems of how diversity and abundance are impacted in the face of ongoing climate variability and change, as they are sensitive to shifts in precipitation, temperature, and changing vegetation structure. The main research question we hope to answer is how the community composition of lizards varies between dominant vegetation types (Mesquite dunes, grasslands, and Creosote Bush flats). Nine sites (3 of each dominant vegetation type) with 16 pitfall traps each (n = 144) were surveyed from June 2016 -- June 2017. 12 lizard species were captured, consisting of 923 total captures …

Activity Patterns Of Whiptail Lizards (Aspidoscelis) Found In The Northern Chihuahuan Desert, Guillermo Alvarez

Open Access Theses & Dissertations

Traditional lizard pitfall traps were modified to allow organisms to escape, while collecting valuable ecological data. Modified camera traps were capable of detecting the same species as traditional traps in a semi-arid environment, without posing the associated mortality risks. Pitfall-camera traps were used to sample the activity of the Side-blotched Lizard (Uta stansburiana) and the Southwestern Fence Lizard (Sceloporus cowlesi) in an urban wetland during four continuous years. Evaluations on activity pattern and the activity overlap between the two species revealed extensive overlap, with minor but significant seasonal shifts mediating coexistence. Traps were also effective at detecting other reptiles, invertebrates, …

Human-Bat Interactions In A Disease Emergence Hotspot: Implications For Human Health And Bat Conservation, Reilly Tempest Jackson

Graduate Theses and Dissertations

Bats are an ecologically important taxon that can host zoonotic pathogens. Globally, many bat species are synanthropic and live closely with humans, often roosting in man-made structures. The spatial overlap between humans and bats creates opportunities for human-bat contact, which can lead to human exposure to bat-borne pathogens and conflicts that cause bat mortality. Despite this risk, little is known about the drivers and characteristics of these human-bat interactions in buildings and work is needed to understand this aspect of the wildlife-urban interface. In Chapter I, I present a literature review that identifies the geographic and taxonomic trends in reported …

How Beavers (Castor Canadensis) Affect Habitat Availability For Two Native Oregon Turtles: Actinemys Marmorata And Chrysemys Picta Bellii, Rodé Krige

University Honors Theses

Oregon is home to two native freshwater turtle species: the northwestern pond turtle and the western painted turtle. Both turtles are Oregon conservation strategy species with a status rating of sensitive, indicating declining populations. Oregon’s decline in these turtle’s populations is thought to be predominantly due to loss and degradation of habitat that results from development and urbanization. Beavers’ ability to dam streams and create ponds may be creating habitat usable by turtles, but the relationship is under-studied. This study assessed water temperature, basking habitat, and overall turtle habitat suitability at beaver-dammed and control ponds in Portland, Oregon. Average basking …

Seagrass Epibiont Biodiversity In The Northern Gulf Of Mexico, Kathryn Wyssmann

University of New Orleans Theses and Dissertations

Epibionts on seagrass leaves contribute substantially to productivity and trophic interactions in seagrass ecosystems. Differences in epibiont assemblages and factors that contribute to epibiont diversity have been little studied on the seagrass Halodule wrightii in the northern Gulf of Mexico (nGoM). We used a metabarcoding approach to describe epibiont assemblages on H. wrightii leaves in four bays across the nGoM and to test whether epibiont assemblages differed spatially at local levels (within bays) or regional levels (from west to east). Furthermore, we tested if epibiont diversity was related to environmental conditions and/or seagrass productivity. Epibiont assemblages differed significantly between bays …

Breaking Virulent: The Coincidental Evolution Of Virulence Factors In Bacteria., Rhiannon Emmanuelle Cecil

Electronic Theses and Dissertations

Understanding how innocuous organisms can evolve to be pathogenic to humans is of increasing global concern. Further, understanding how existing pathogens may evolved to be more virulent is also vital to our ability to provide healthcare to people afflicted with diseases that promote chronic bacterial infections, such as cystic fibrosis. With the rise of antibiotic resistance in both bacteria and fungi it is paramount that new therapeutics are identified. Understanding what mutations occur that result in increased virulence in microbes can potentially provide new targets for antimicrobial drugs to combat antibiotic resistance. The Coincidental Evolution Hypothesis is a fundamental hypothesis …

Effects Of A Major Hurricane On Dynamics, Structure, And Composition Of Mississippi River Delta Forests, Lance C. Umlang

LSU Doctoral Dissertations

Tropical cyclones recurrently influence coastal forests worldwide. Tree survival (resistance) and post-cyclone recruitment (resilience) can vary with cyclone intensity, producing differences in composition, arboreal structure, and dynamics among affected forests. Studies of tropical cyclone wind effects on coastal forests typically emphasize damage more than post-cyclone responses. We hypothesized that intense cyclones might produce large, stratum-dependent effects that prevent affected forests from returning to pre-storm conditions. We explored direct effects of major Hurricane Katrina and post-hurricane changes in oak-dominated bottomland and cypress/tupelo-dominated swamp forests within the inactive portion of the Mississippi River deltaic plain. Overall mortality was high (14-25%) but concentrated …

Short-Term Versus Long-Term Effects Of Nitrogen Addition And Warming On Ecosystem N Dynamics In A Grass-Dominated Temperate Old Field, Benjamin F. A. Souriol

Electronic Thesis and Dissertation Repository

Increased atmospheric nitrogen (N) deposition and climate warming are both anticipated to influence the ecosystem N dynamics of northern temperate ecosystems substantially over the next century. Nevertheless, in field experiments with N addition and warming treatments, temporal scale can play an important role in determining the extent of treatment effects on N dynamics, and it is unclear to what extent the results of short-term studies can be extrapolated to responses over longer time scales. I compared the short-term versus long-term effects of N addition and warming on net N mineralization, N leaching, and N retention in a grass-dominated old field. …

The Detectability Of Atlantic Salmon (Salmo Salar) Microsatellite And Mitochondrial Environmental Dna, Simone N. Miklosi

Electronic Thesis and Dissertation Repository

Little is known about what information can be gathered from microsatellite eDNA. It is important to gain a deeper understanding of the detectability and analysis of microsatellite eDNA because it could provide information about population size that mitochondrial eDNA cannot. Water samples were collected from tank and river experiments, and rivers known to contain Atlantic salmon (Salmo salar) and analyzed for Atlantic salmon mitochondrial and microsatellite eDNA. Mitochondrial eDNA was detected from all the tank experiments and 10 out of 15 rivers known to contain Atlantic salmon. Microsatellite eDNA was detected from all the tank experiments and none …

Effects Of Large Wood Additions On Basal Resources, Macroinvertebrates, And Ecosystem Processes In The Narraguagus River, Maine, Val Watson

Electronic Theses and Dissertations

Ecological restoration is an increasingly common practice across ecosystems, and current practices aim to restore the biological and physical processes underlying ecosystem function, often for the sake of endangered higher-level consumers. Studies of restoration outcomes often report few or inconsistent ecological changes, and monitoring of restoration projects rarely measures ecological processes. Monitoring also usually measures outcomes at a single scale, despite the prevalence of scale- dependent phenomena across ecosystems. My thesis uses measurements of ecological processes to assess restoration response and evaluates responses across multiple scales. I focus here on a long-term large wood addition project on the Narraguagus River …

The Influence Of Climate And Landscape On Allocapnia Mohri Distribution In Arkansas, Brianna Leigh Annaratone

Graduate Theses and Dissertations

Stoneflies are a globally threatened aquatic insect order. In Arkansas, a diverse group of winter stonefly (Capniidae: Allocapnia) have not been surveyed since the 1980s, likely because species-level identification requires the rarely-collected adult form. Allocapnia mohri, a regional endemic, was previously commonly found in mountainous, intermittent streams from the Ouachita Mountains ecoregion north to the Ozark Highlands, but no species distributional models including land use or climate variables exist to our knowledge. We collected adults from 70 stream reaches from the historic Arkansas range from November to April 2020 and 2021. We modeled distributions using random forest (RF) models populated …

Shedding In The Timber Rattlesnake: Natural Patterns, Endocrinological Underpinnings, Temporal And Energetic Effort, And Integration As A Reptilian Life History Trait, Maxwell D. Carnes-Mason

Graduate Theses and Dissertations

The semi-frequent replacement of the epidermis (ecdysis) is a characteristic trait of reptiles. Whereas all reptiles regularly engage in some degree of skin shedding, skin morphology in snakes necessitates the synchronous replacement of the entire epidermis and facilitates the subsequent removal of the old layer as a single sheet. To date, the ubiquitous process has garnered little attention from researchers because snakes shed with unpredictable timing and frequency and are exceedingly cryptic during ecdytic cycles; previously impeding detailed physiological or ecological investigations of the process in the clade. Because of the lack of study, ecdysis is often viewed as a …

Evidence Of Competitive Release Following Overstory Mortality In A Semi-Arid Piñon-Juniper Woodland, Corrie D. Gonzalez

Biology ETDs

Extreme temperatures and severe drought events have led to widespread tree mortality worldwide. In semi-arid regions of the Southwest United States, these events pose a significant threat to piñon-juniper (PJ) woodlands. We studied the effects of piñon and juniper mortality on the growth and physiology of existing saplings in PJ woodlands by analyzing water status, photosynthetic activity, and tissue chemistry to gain insights into these impacts. Juniper saplings exhibited improved water status and water use efficiency in response to overstory mortality, whereas piñon saplings did not. Additionally, both piñon and juniper saplings exhibited increased photosynthetic rates, increased photosynthetic capacity, and …

Resolving The Paradox Of Polyploidy: Underexplored Facets Of Polyploid Plants, Benjamin Gerstner

Biology ETDs

Polyploidy, or whole genome duplication, is a common phenomenon in plants, but the establishment and persistence of mixed-ploidy populations remains a paradox. This dissertation explores factors that contribute to the persistence and establishment of mixed-ploidy populations in nature. The first chapter investigates the role of unreduced gametes in neopolyploid establishment and finds that variability in their formation rate can have a significant impact on polyploid establishment and persistence. The second chapter searches for evidence of soil microbes exhibiting ploidy-specificity, a pre-condition for microbe-mediated niche differentiation, a possible stabilizing mechanism contributing to ploidy coexistence. Finally, the third chapter tests for microbe-mediated …

The Importance Of Soil Carbon In Large-Scale Shrub Removal Practices In The Chihuahuan Desert, Kathleen Schaeffer

Open Access Theses & Dissertations

Shrub encroachment is a worldwide phenomenon that affects multiple biomes at different ecological and anthropogenic levels. In dryland ecosystems, shrub encroachment is a noted concern amongst land managers, as it can lead to a loss of soil resources and biodiversity. To mitigate the negative effects of shrub encroachment in Drylands, land managers can implement large-scale shrub removal practices. These land restoration practices can shift landscapes to novel ecosystems, where resulting plant communities can vary following treatments. Grass recovery or increasing herbaceous cover is often a primary goal of these treatments, however predicting which sites may show higher grass responses to …

An Ecological Survey Of East Texas Salamanders Across The Camp Tyler Outdoor Field School In Smith County, Texas, Justin C. Hunt

Biology Theses

Amphibians are a unique class of organisms with a very long and storied evolutionary history of survival. Many modern amphibian clades occupy several vital ecological roles within their native freshwater environments. One of these roles, typically includes functioning as an ecological indicator species, whereby the presence of stable and diverse populations of many amphibian species, including salamanders, within a freshwater ecosystem have long been considered ecological indicators of good habitat quality and stable ecosystem health. Similarly, salamanders also function as important members of their local food webs and act as valuable mediators of complex trophic hierarchies to facilitate nutrient cycling …

Monitoring The Effects Of Poultry Waste On Fishes And Macroinvertebrates In The Sabine River, Karley R. Parker

Biology Theses

Freshwater is a vital resource that provides life and sustainability for almost all organisms on Earth. It is important to maintain its health and protect it from emerging pollutants that pose a threat to the organisms that use it. Pollution continues to threaten the well-being of the environment’s freshwater sources all around the world that could lead to damaging effects in the future. The Sabine River is a major freshwater resource in the east Texas and western Louisiana areas that provides a habitat for thousands of organisms as well as other domestic uses for humans. In 2019, a waste discharge …

Phylogeny And Taxonomy Of Genus Physaria In North America, Binoshi Hettihewa

Theses

Physaria is a genus of ~108 species belonging to family Brassicaceae that is predominantly distributed in Western North America, but one species occurs in Arctic Russia and Northern Canada and several species occur in South America. Regardless of the vast number of species in the genus, the genus lacks a well-resolved phylogeny representing many taxa, partially because phylogeny reconstruction is complicated by the fact that many species of Physaria vary in chromosome numbers and ploidy levels. In chapter 1, we review how polyploids are formed and become established and summarize what is known about variation in chromosome number and ploidy …

Phylogeographic History Of The Leaf-Eared Mouse, Phyllotis Xanthopygus Complex, Tabitha R. Mcfarland

Biology ETDs

Museum collections provide essential biodiversity sampling needed to understand the species limits, phylogeny, and biogeographic history of mammals, all key features of the foundation for comparative analyses in ecology and evolution. We add to this framework a diverse assemblage of species of leaf-eared mice (genus Phyllotis) in South America and then focus on the Phyllotis xanthopygus complex by combining available mitochondrial sequence (cytochrome b; cytb) data (351 GenBank samples) with 52 newly sequenced museum samples from the northern extent of this complex’s range (51 from Bolivia and 1 from northern Chile) to reconstruct evolutionary relationships using maximum …

Cadmium And Salinity Stressor Antagonism On Vallisneria Neotropicalis, Christopher P. Mikolaitis

<strong> Theses and Dissertations </strong>

Submerged macrophytes form the foundation of freshwater ecosystems. These organisms are sessile and are very susceptible to shifts in their environment. Heavy metals are of particular concern as they can be sequestered indefinitely in sediments and are readily taken up by rooted vegetation. In the presence of saltwater intrusions, these metals can interact with salt ions potentially changing their availability to submerged vegetation. In this study a freshwater macrophyte, Vallisneria neotropicalis, was used as a test species for interactive effects between Cd, a non-essential heavy metal, and salt stress. The metrics used to establish the individual as well as …

Sympatric Soil Microbe Interactions Between Streptomyces And Fusarium Isolates, Lehren A. Olk-Szost

All NMU Master's Theses

Interkingdom interactions between soil bacteria and fungi may play a critical role in occurrence of disease suppressive soils, yet our understanding of these interactions remains limited. Streptomyces are well-known producers of antimicrobial compounds important to medicine and agriculture. Production of these secondary metabolites is often mediated by quorum sensing. Most Streptomyces research occurs in single species experiments, yet new metabolites have been discovered in interspecies co-culture experiments. Interspecies, intergenic, and interkingdom co-culture research will likely reveal many valuable compounds, and strengthen our understanding of complex ecological interactions in soil microbiomes. Interactions between sympatric Streptomyces and Fusarium isolates from disease suppressive …

Trophic Dynamics Of The Lake Superior Fish Community, Ariel Edwards

All NMU Master's Theses

The Lake Superior food web has undergone many changes in recent decades, including the rehabilitation of the native apex predator lake charr (Salvelinus namaycush) and the introduction of several nonnative species. The trophic linkages and ecological requirements of the entire fish community, including predators and prey fishes, has not been assessed on a whole-lake scale in over a decade. Here, I investigated the trophic dynamics across multiple regions of the lake, and estimated the consumptive effect of lean lake charr in one region of Lake Superior. From April to October of 2021, a total of five predator, four …

The Effects Of Urban Landscape, Soundscape, And Light Pollution On Avian Diversity And Nesting In South San Antonio, Texas, Alfredo Llamas

Masters Theses

As critical habitat continues to dwindle due to the expansion of urbanization, alternative habitat in urban ecosystems becomes a necessary natural resource for the survival of birds. In the last decade, local San Antonio environmental authorities have focused their efforts on restoring the San Antonio Mission Reach. Ecological revitalization of the San Antonio Mission Reach could increase avian, and flora biodiversity with ongoing restoration, yet how birds use restored habitat has not been assessed. Additionally, south of the Reach, two more peri-urban sites have great potential to be high quality habitat for birds but have not been surveyed for nesting …

The Effects Of Anthropogenic Sensory Pollution On Arthropod Diversity And Pollinator Behavior, Sierra Dee Rodriguez, Jennifer N. Phillips Phd

Masters Theses

Pollinators provide a key ecological function in terrestrial ecosystems, yet in recent years, they have encountered unprecedented declines, likely due to anthropogenic change. Light and noise pollution, which can interfere with the visual and auditory systems of animals that regulate daily behaviors, are important factors to consider when communities are encroached by human development. While many researchers have looked at how vertebrate species behaviorally react to human caused habitat degradation and sensory pollution, little is known about how invertebrates, including arthropod pollinators, are affected, and whether there is a negative cascading effect on the plants that they pollinate. This research …

Locomotion And Life History In A Leaping Primate: Mechanics And Energetics Of Movement Throughout The Propithecus Lifespan, Nicholas Heslep

Masters Theses, 2020-current

Arboreal primates are typically altricial, exhibit long juvenile periods, and use dynamic locomotor behaviors that can be challenging and risky. Sifaka (Propithecus verreauxi) have particularly slow life histories for their size, with long juvenile periods, protracted reproductive careers, and long life spans. Slow somatic growth poses potential mechanical challenges for juvenile sifaka who use thigh-powered vertical clinging and leaping to follow group members during travel. I examined mechanical and energetic costs of movement in developing sifaka. I instrumented 8 wild sifaka (3 yearlings, 3 subadults, 2 adults) in 4 social groups with inertial sensors measuring tri-axial acceleration for …

Understanding Context Dependent Responses To Climate Change In Arizona Tiger Salamanders (Ambystoma Mavortium Nebulosum), Kentrell Richardson

Masters Theses, 2020-current

Future emissions scenarios project climate change to increase average global temperatures by at least two ℃ in the next 50 years resulting in changes in local climate and causing increased variability within microclimates. Ectotherms are especially sensitive to climate change due to their dependence on environmental temperatures to regulate physiological functions. Changes in temperature are likely to impact thermally cued processes within amphibians and result in changes in variable magnitudes and directions within local populations.

Salamanders were placed in cups and partially submerged in a water bath and heated at a rate of ~0.27℃/ minute. Once salamanders were unable to …