Ecology and Evolutionary Biology Commons^™

Do Heat Waves Drive Natural Selection In Damselflies?, Adam Baranyk

Biological Sciences Undergraduate Honors Theses

Climate change has led to changes in both mean temperatures and temperature extremes over the recent years. These changes have had differential effects on animals throughout the world. Ectotherms depend on their external environment for thermal regulation, making them especially susceptible to temperature extremes. It is not yet clear whether there is a relationship between physical traits in ectotherms, and survivorship throughout a heat wave. That is, whether or not temperature extremes driven survival selection. In this study, a heat wave was simulated artificially using thermally regulated mesocosms at different temperatures (18°C, 22° C, 26° C, 30° C) with a …

Evaluating Aspen Seedling Outplanting Success Following High Severity Wildfire In The Southwest, Sarah M. Kapel

All Graduate Theses and Dissertations, Fall 2023 to Present

Quaking aspen (Populus tremuloides Michx.) is an ecologically important forest species in the western U.S. Aspen forests host a variety of understory species, are critical wildlife habitat, and are considered a "natural fuel break" since they are less likely to support crown fires than conifers. Because of climate change and altered disturbance regimes, populations are declining, and innovative strategies are needed to restore aspen. Planting aspen seedlings is a solution, though not a common practice in the West and has been met with high mortality in past experiments. For aspen planting to be more broadly implemented, managers need guidance …

The Effects Of Aboveground Herbivory On Root Traits And Root Decomposition, Emily A. Chavez

All Graduate Theses and Dissertations, Fall 2023 to Present

Soil holds more carbon (C) than the Earth's atmosphere and vegetation combined. Soil loses carbon through soil respiration and releases CO₂ from the soil. The soil respiration rate can vary based on the chemistry of the plant litter inputs and physical factors, such as soil temperature and nutrient content. In Alaska's Yukon-Kuskokwim (YK) Delta, grazing by geese affects the chemistry of plants and the soil's physical qualities, thus altering the rate of soil respiration. Although we know that goose herbivory leads to changes in the rate of soil respiration, we know very little about how goose herbivory affects the …

Spatiotemporal Dynamics Of Disease: Social And Environmental Drivers Of Movement, Connectivity, And Disease Transmission In Bighorn Sheep, Lauren E. Ricci

All Graduate Theses and Dissertations, Fall 2023 to Present

Movement is a fundamental component of animal ecology. Animals move in order to access resources and avoid risk. Movement decisions aggregated across time determine how individuals use space, contact dynamics between individuals within a population, and connectivity across a species range. These patterns that emerge from movement decisions have downstream implications for many ecological processes and a mechanistic understanding of movement can help answer broader questions about ecology.

Disease dynamics are intrinsically tied to movement. Understanding the mechanisms that drive movement can elucidate how disease will spread and impact host populations. In this vein, I employed a suite of movement …

Revegetation Strategies For Native Wetland Plant Restoration In The Face Of Phragmites Australis Reinvasion And Hydrologic Extremes, Maddie Houde

All Graduate Theses and Dissertations, Fall 2023 to Present

Reestablishing native plant communities in degraded habitats through seeding or planting ("revegetation") is a necessary step to restore ecosystems and their functions (e.g., supporting biodiversity, nutrient cycling, etc.). Globally, wetlands have suffered high rates of degradation and also experience numerous invasions. Invasive species are those that cause environmental, economic, or societal harm. Phragmites australis is a widespread invasive species that outcompetes native plants and reduces habitat diversity. Reestablishing native plant communities can limit P. australis invasion, yet effective methods to do so remain somewhat untested in wetlands. Additionally, stressful environmental conditions can increase plant mortality in revegetation efforts. In semi-arid …

Experimental Nonnative Wood Addition Enhances Instream Habitat For Native Fishes And Investigating Dryland River Alterations, Benjamin J. Miller

All Graduate Theses and Dissertations, Fall 2023 to Present

The rivers of the Colorado River Basin (CRB) have been degraded by human activities such flow regulation, water overallocation, and the introduction of invasive riparian vegetation (primarily tamarisk tamarix spp. and Russian olive Elaeagnus angustifolia). These stressors have resulted in widespread habitat loss and simplification, which is a major contributor to the endangerment of native fishes in the CRB.

The objectives of this study were to 1) assess the effectiveness of enhancing native fish habitat by experimentally adding cut wood from nonnative Russian olive to the San Juan River, a highly degraded dryland river, and 2) determine the …

The Decline In Monarch Butterfly, Danaus Plexippus, Populations: An Example Of The Global Threat To Biodiversity, Olivia Sidoti

Honors Projects

Biodiversity encompasses the variety of all life on Earth and how these aspects of nature interact with each other. To have stable and abundant biodiversity, vast amounts of species and organisms are required within an ecosystem. As a result of the increase in negative impacts of human activities and behaviors on the health of nature, biodiversity has been decreasing. An example of the decrease in biodiversity is depicted by the recent decline of the monarch butterfly species. The monarch butterfly is an iconic North American insect that is experiencing a decline in its population due to threats such as deforestation, …

Spatial Mapping Of The Benthic Community And How It Is Used To Research Effects Of Dredging In Louisiana's Lake Borgne., Meghan Johnson

LSU Master's Theses

Benthic communities are vitally important for healthy aquatic ecosystems across Louisiana’s coast. Specifically in Lake Borgne, ecologically important species of fish like the Gulf Sturgeon (Acipenser oxyrinchus desotoi) rely on benthic macrofauna as their main food source. The purpose of this study was to determine the spatial landscape of biodiversity and abundance of the benthic macrofauna community in Lake Borgne. Environmental conditions played a key role in community structure during the study period (fall 2021 through summer 2023) with a major drought occurring in 2023. In 2023, the decline in the abundance of most benthic invertebrates and in …

Documenting The Southern Range Terminus Of The Wood Frog (Lithobates Sylvaticus) In North America, Christian Braswell

Theses

The Wood Frog (Lithobates sylvaticus) holds a remarkable position in North American amphibian biology, with its range extending from the Arctic Circle down to the near sub-tropical southeastern United States. This thesis presents a novel quantitative polymerase chain reaction analysis (qPCR) primer specific to L. sylvaticus and a survey effort regarding the southernmost distribution and detection of this species in Alabama through the application of environmental DNA (eDNA) sampling techniques. By investigating historical data and employing advanced genetic methodologies, this research provides insights into the contemporary status and distribution of the Wood Frog. This research is important to …

Use Of Unoccupied Aerial Vehicle (Drones) Based Remote Sensing To Model Platform Topography And Identify Human-Made Earthen Barriers In Salt Marshes, Joshua J. Ward

Masters Theses

Elevation is a foundational driver of salt marsh morphology. Elevation governs inundation and hydrological patterns, vegetation distribution, and soil health. Anthropogenic impacts at grand scales (e.g., rising sea levels) and local scales (e.g., infrastructure) have altered the elevation of the salt marsh surface, changing the topography and morphology of these ecosystems. This study establishes and assesses means to document and analyze these impacts using Unoccupied Aerial Vehicle (UAV) based remote sensing to model platform topography. This thesis’s first and primary study presents and compares methods of producing high-resolution digital terrain models (DTMs) with UAV-based Digital Aerial Photogrammetry (DAP) and Light …

Prescribed Fire Effects On Microbial Communities And Functions In Managed Ecosystems, Viet Dao

LSU Doctoral Dissertations

Microbes (both fungi and bacteria) serve important ecosystem functional roles in nutrient cycling and decomposition, which affect ecosystem response following disturbances such as prescribed fire. A multitude of abiotic and biotic factors influence microbial community compositions, which then drive microbial ecosystem functions. The factors driving microbial communities further change due to fire disturbances and progression with time. Although prescribed fire is commonly used as a technique for ecosystem management, the effects of fire on microbial communities or their functions are simply understudied. Ecosystem management decisions tend to focus on plant and ecosystem post-fire responses. Thus, incorporation of fire effects on …

The Impacts Of Environment And Host Evolutionary Relationships On Lemur Microbiota, Rachel B. Burten

Doctoral Dissertations

Recent studies have shown that the mammal microbiome is modified by environmental conditions, and that reduced microbiome functionality is associated with host health issues. Microbiome data in wild and captive primate populations can therefore be used to assess their health as they encounter a variety of environments. Comparative studies of the microbiome can also inform disease ecology, conservation, and captive management strategies tailored to different primate species. Therefore, this study examines how the hair, oral, and gut microbiota of nine wild and captive lemur species are determined by host phylogenetic relationships and host environment. I found that host species identity …

The Wild Tomato Clade Offers Insights Into Fleshy Fruit Trait Evolution At The Phenotypic And Molecular Levels, Jacob R. Barnett

Doctoral Dissertations

Biologists have long been fascinated by the diversity of fleshy fruits, yet questions remain as to how this variety has evolved. According to the dispersal syndrome hypothesis, flowering plants improved their reproductive success by producing fleshy fruits with appealing combinations of traits that attract animal dispersers. However, animal preferences may not be the only selective pressure driving fruit trait diversity—conflicting forces include damage-inflicting seed predators and pathogens, abiotic habitat conditions, or constraints stemming from non-adaptive mechanical, developmental, or phylogenetic limitations. Few studies have examined the early stages of fleshy fruit evolution across an entire clade of recently diverged plant species. …

Species Delimitation Of Slimy Salamanders, Plethodon Kisatchie And Plethodon Mississippi, Across The Lower Mississippi River, Brock Hunter Stevenson

Master's Theses

Species are fundamental units of biodiversity yet delimiting species can be challenging. Slimy Salamanders of the Plethodon glutinosus species complex are a classic example of cryptic species for which species boundaries and relationships have proved difficult to determine. Once thought to be a single species ranging across the eastern United States, protein analysis revealed high genetic divergences among geographically distinct groups of populations, leading to 16 species being recognized within the group. Two of these species, the Louisiana Slimy Salamander (Plethodon kisatchie) and the Mississippi Slimy Salamander (Plethodon mississippi), are closely related but occur on opposite sides of the Mississippi …

Effects Of Anthropogenic Noise On The Provisioning Behavior Of Western Bluebirds And Artificial Light At Night On Nestling Development, Kerstin H. Ozkan

Master's Theses

Sensory environments are rapidly changing due to increased human activity in urban and non-urban areas alike. For instance, background sounds can interfere with parent-offspring communication and mask cues reflective of predation risk, resulting in elevated vigilance at the cost of provisioning. In chapter 1, we studied nestling provisioning behavior among Western Bluebirds (Sialia mexicana) in response to short-term (1 hr) and long-term (continuous exposure throughout nesting period) noise exposure. Provisioning rates were lower at nests exposed to short-term experimental traffic noise compared to exposure to ambient background sounds. Trial order strongly influenced provisioning behavior, with the decline in …

Towards Sociobiogeochemistry: Critical Perspectives On Anthropogenic Alterations To Soil Nitrogen Chemistry Via U.S. Urban And Suburban Development, Christopher D. Ryan

Dissertations, Theses, and Capstone Projects

The ecological impacts of changes to land use are relevant to concerns about climate change, eutrophication of waterbodies, and reductions in biodiversity. As a foundational component of ecosystem functioning, changes to soil biogeochemistry have significant effects on overall ecosystem health. With cities continuing to grow and develop in extent, the impacts of urbanization and suburbanization on soils are of particular concern. Despite a wide range of natural climatic and geologic conditions, several factors have driven similar patterns of land transformation and management across the United States. In particular, federal initiatives including the Home Owners Loan Corporation, the Federal Housing Administration, …

Literature Review Nature-Based Art Therapy Exploring Connections And Relationships, Janell Lopez-Curtis

Expressive Therapies Capstone Theses

Art therapy is a modality used in clinical psychotherapy. It is supported through both quantitative and qualitative research. Branching out from art therapy is nature-based art therapy. This branch of expressive therapies holds the potential to be beneficial as art therapy due to the interconnected access to the scientific fields of ecology, ecopsychology, art therapy, expressive therapies, and other nature-based therapeutic activities; this includes intersectionality in ecological theories such as ecofeminism and deep ecology as well. Through an exploration of literature, this paper will provide definitions and theory-based support through reviewing clinical psychotherapy, evidence-based practices, and art therapy theories. The …

Investigating The Roles Of Plants, Fungi, And Biocrusts In Nutrient Movement Within Dryland Ecosystems, Catherine E. Cort

Open Access Theses & Dissertations

In dryland ecosystems, plant productivity and microbial decomposition are often separated in space and time due to the asynchronous availability of soil moisture and organic matter inputs. It has been proposed that fungi play a key functional role in connecting these cycles by facilitating movement of water, carbon (C), and nitrogen (N) through a network of shared hyphae between plant roots and biological soil crust (biocrust) communities at the soil surface. This connection, also known as the â??fungal loop,â?? effectively re-couples processes of nutrient release and uptake between primary producers and minimizes ecosystem N losses due to leaching, erosion, and …

Quantifying The Ecological Effects Of Salix Fragilis On Riparian Habitat In Kittitas County, Washington, Landon Shaffer

All Master's Theses

Invasive species threaten plant community structure and function globally. Riparian areas, the zone near streams where water influences vegetation, are especially sensitive to invasive species colonization, suffering large-scale shifts in community composition. Salix fragilis (crack willow) is a nonnative riparian species abundant in the lower elevation tributaries of central Washington. Some speculate whether this willow should be listed as invasive in Washington, despite a lack of regional supporting evidence. I studied riparian communities dominated by either S. fragilis or native species in the Kittitas Valley and measured biodiversity, quantified differences in solar attenuation, and compared leaf decomposition rates to learn …

From Rain Drops To Rivers: Unraveling Aridification's Influence On Coastal Stream Ecosystem Dynamics, Sean Kelly Kinard

Dissertations, Theses, and Masters Projects

This dissertation addresses the escalating threat of aridification to global freshwater ecosystems due to anthropogenic climate change, focusing on South-Central Texas, USA, using a space-for-time approach along a precipitation gradient from semi-arid to sub-humid. Over the 2017-2020 survey period, I integrated community, stable isotope, climate, and hydrologic data.In Chapter 2, my initial assessment of fish and invertebrate communities along the precipitation gradient unveiled compositional shifts and other nuanced responses. Positive correlations between fish diversity and rainfall, coupled with unexpected invertebrate diversity patterns, underscored the role of water quality in shaping fish assemblages. Drier conditions imposed abiotic filters, reducing diversity and …

Variation In Mainland Northwest Territories Late-Winter Muskox (Ovibos Moschatus) Density Estimations And Habitat Associations Above And Below Treeline., Charlotte Rentmeister

Theses and Dissertations (Comprehensive)

The Arctic and Sub-Arctic ecosystems are seeing accelerated changes in temperature, landcover, and consequently species abundance and distributions. Reliable distributions, and associated population density estimates, are essential for effective conservation and management efforts. Growing concerns from northern communities regarding the relationship between muskox and declining caribou populations strengthens the need for updated information on muskox populations within mainland Northwest Territories (NWT). The first objective for my research was to quantify and map updated winter estimates of abundance, density, and distribution of muskoxen within three recent survey regions located in mainland NWT, using a multiple covariate distance sampling method (MCDS), paired …

Screening H3 Histone Acetylation In A Wild Bird, The House Sparrow (Passer Domesticus), Daniella Ray

Electronic Theses and Dissertations

Epigenetic mechanisms are increasingly understood to have major impacts across ecology. However, one molecular epigenetic mechanism, DNA methylation, currently dominates the literature. A second mechanism, histone modification, is likely important to ecologically relevant phenotypes and thus warrants investigation, especially because molecular interplay between methylation and histone acetylation can strongly affect gene expression. There are a limited number of histone acetylation studies on non-model organisms, yet those that exist show that it can impact gene expression and phenotypic plasticity. Wild birds provide an excellent system to investigate histone acetylation, as free-living individuals must rapidly adjust to environmental change. Here, we screen …

Quantifying Wastewater Contributions To The Upper Clark Fork River, Claire Utzman

Graduate Student Theses, Dissertations, & Professional Papers

Though algae are at the base of food webs in many rivers, large algal blooms are increasing in frequency and can cause problems with nutrient cycling, depletion of oxygen supplies at night, and release of toxic chemicals. One leading cause of algal blooms is nutrient loading into rivers, and controlling nutrient release in wastewater is one approach that can help limit algal growth. To reduce the intensity of algal blooms in the Clark Fork River in western Montana, numeric nutrient standards were put in place that regulated the release of the nutrients nitrogen and phosphorus into the river from wastewater. …

A Conservation Model: Costa Rican Conservation Strategies Effectively Preserve Their Threatened Primates, Ryan Belmont

Regis University Student Publications (comprehensive collection)

The wildlife of Costa Rica has experienced various anthropogenic threats over the last century including climate change and agricultural expansion. The mantled howler monkey (Alloutta palliata), Central American spider monkey (Ateles geoffroyi), white-faced capuchin (Cebus imitator), and the Central American squirrel monkey (Saimiri oerstedii) are Costa Rica’s native primates that face several anthropogenic threats such as deforestation for agriculture and climate change. In response to increased threats to its four native species of non-human primates, Costa Rica has implemented effective governmental conservation tactics such as the Payments for Environmental Services program, ecotourism …

Exploring The Consistency Of Flow Regimes Within And Among Ecoregions Of The Southeastern United States, Frank Paul Braun Iv

Electronic Theses and Dissertations

Human manipulation of river systems has long been a known contributor to the loss of freshwater biodiversity. By accounting for environmental causes of hydrologic variation among rivers, we can better understand how ecoregion mediates flow regimes and forecast species that may be at risk. Presumably, natural variation associated with ecoregion boundaries exerts strong influence on flow regimes, and may mediate relationships between other features (e.g., land use, dam operations) and hydrology. However, such between-ecoregion variation is poorly investigated, particularly at fine spatial and temporal scales. I characterized 10 hydrologic metrics, representing the five key dimensions of the flow regime (magnitude, …

Adaptation Reshapes The Distribution Of Fitness Effects, Diego Tenoch Morales Lopez

Electronic Thesis and Dissertation Repository

The process of adaptation has been of interest since the XIX century, when Darwin first proposed the idea of natural selection. Since then, there has been a myriad of theoretical and empirical works that have expanded the field. From the many evolutionary insights these works have produced, a foundational idea is that spontaneous mutations in the genome of organisms can produce changes to their reproductive success that might confer an advantage for the mutant organisms with respect to their peers. Therefore, mutations drive adaptive evolution by virtue of their heritable effects on fitness. Empirical measures of the distribution of these …

Interactive Effects Of Sublethal Concentrations Of Fracking Biocides And Abandoned Mine Drainage On Amphipod Behavior, Kelly Lenhart

Electronic Theses and Dissertations

This thesis examined the sublethal effects of three pollutants, namely glutaraldehyde, 4,4-dimethyloxazolidine (DMO), and abandoned mine drainage (AMD), on amphipods. The primary objective was to investigate their combined effects on amphipods. The three pollutants, despite having the potential to combine in the environment, have not been studied to determine their potential for detrimental interactive effects which could result in unexpected environmental damage.

The research employed a series of experimental setups involving controlled exposure of amphipods to varying, putatively sublethal, concentrations of the chemicals of interest. Subsequently, effects were assessed via both behavioral and feeding assessments. To facilitate this analysis, novel …

Targeting Macrophytes: Increased Water Quality Through Optimized Vegetation Considerations For Constructed Wetlands, Austin Mcbrady

Masters Theses

This study of constructed wetland design investigated relationships between macrophyte species selection and planting density for water quality improvement. A lab-scale wetland was compared against a pilot-scale wetland in San Antonio, Texas at Mitchell Lake to measure differences in effluent water quality improvement using three native macrophyte species. Using a novel, two-phase method, a targeting macrophyte was identified from among other species based on its marked capability for improving water quality factors, then was planted in varied majority densities to compare differences in treatment effectiveness. The results of this study showed that this complimentary approach to wetland design displayed significant …

Regeneration Response To Salvage Logging Following Tornado Disturbance, Colby K. Bosley-Smith

Electronic Theses and Dissertations

In an era of increasing natural disturbances, successful tree regeneration has grown more difficult to achieve. Salvage logging, a common management response to disturbance, may further impede regeneration success, although published literature currently remains inconclusive. In 2013, a rare tornado in northcentral Maine, USA, and subsequent salvage operation created three clear ‘treatments’ for evaluation of post-disturbance regeneration: blowdown, blowdown followed by salvage logging and an undisturbed control. In the summers of 2022 and 2023, (nine and ten) years post-tornado, we revisited this site to examine regeneration outcomes.

During the summer of 2022, we evaluated stand structure and regeneration success of …

Assessing The Role Of The Microbiome, Parasite Infections, And Movement In Avian Health, Olivia N. Choi

Electronic Theses and Dissertations

Avian health encompasses the physical, physiological, and behavioral well-being of birds. Assessing avian health is not only important for the conservation and management of wild birds and the recreational economy, but also for the management of infectious diseases that threaten public health and agriculture. Birds, comprising approximately 10,000 species and an estimated 50 billion individuals worldwide, are known to be involved in the spread of pathogens, some of which are zoonotic (from animals to humans), such as avian influenza and West Nile viruses. Individual measures of avian health may include physical measurements (e.g., body mass, wing length), pathogen infection status, …