Terrestrial and Aquatic Ecology Commons^™

Leveraging Mammal Mycophagy To Determine Environmental Drivers Of Truffle Diversity, Brittany Hartsock

Electronic Theses and Dissertations

Many mycorrhizal fungi are hypogeous (truffle-forming), producing underground fruiting bodies. Studying truffles is inherently challenging due to their hidden nature. However, mycophagous mammals provide a unique opportunity to study hypogeous fungi because they rely on truffles as a food source. Although several truffle species have recently been described in the southern Appalachian region, their fruiting patterns remain poorly understood. To address this, we quantified truffle richness and spore loads from 670 Peromyscus scat samples collected across 42 sites spanning an environmental gradient during 2024 in the Blue Ridge Mountains of East Tennessee. We found that truffle richness and spore abundance …

Spatial And Hydrologic Effects Of Climate Change And Urbanization On Freshwater Fish Communities In North Georgia Watersheds, Mayuko Mizutani

Master's Theses

Urbanization and climate change are altering streamflow and land cover across the southeastern United States, threatening freshwater biodiversity in rivers already burdened by impoundments and habitat loss. I investigated how changes in streamflow and land cover might affect fish community biodiversity in the Etowah River watershed of North Georgia. By combining a dataset of fish collections from 1999 through 2019 with contemporaneous land use and daily streamflow, I was able to model fish community responses to urbanization and climate-driven hydrologic changes and then forecast fish community structure under multiple CMIP6 global climate models and greenhouse gas emissions scenarios (SSP2-4.5 and …

The Role Of Phenotypic Plasticity And Bet-Hedging In Coping With Unpredictable Temperature Fluctuations In The Marine Annelid Ophryotrocha Labronica, Gabrielle Dawn Newton

Biological Sciences Theses & Dissertations

Coastal ecosystems are increasingly exposed to unpredictable temperature fluctuations, potentially favoring strategies that buffer populations against environmental uncertainty. This study examines how phenotypic plasticity and diversified bet-hedging contribute to variation in life-history traits under differing thermal predictability in the marine annelid Ophryotrocha labronica. After three generations at 24 °C, broods were reared for three generations under four thermal regimes: constant 24 °C (C24), constant 27 °C (C27), predictable fluctuations (Fp), and unpredictable fluctuations (Fu). Survival was assessed before and after acclimation to evaluate selective pressure among regimes. Age at maturity, fecundity, and growth rate were used to quantify plasticity (trait …

Effects Of Urbanization On Barrier Island Bobcats, Meghan P. Keating

All Dissertations

Urbanization is a leading driver of ecological change and presents unique challenges for carnivores by altering habitat availability, prey communities, and exposure to anthropogenic threats. Although many carnivore species persist in developed landscapes, the ecological and demographic consequences of urbanization often remain poorly understood, particularly over long timescales. Using one of the longest-running studies of a free-ranging carnivore population, I evaluated the effects of urbanization on the behavior, resource use, exposure risk, and population dynamics of bobcats (Lynx rufus) inhabiting a residentially developed barrier island in coastal South Carolina, USA. I first examined temporal and spatial responses to …

Evaluating Fish Assemblages At An Early-Stage Living Shoreline Project In Lake Pontchartrain, Collin Glaser

LSU New Orleans Theses and Dissertations

Living shorelines are an increasingly popular restoration approach for reducing erosion while improving habitat quality. The Bucktown Living Shoreline Project is a large-scale restoration effort along the southern shore of Lake Pontchartrain aimed at enhancing coastal resilience and restoring historic marsh habitat. This thesis evaluated early fish assemblage response to the Bucktown Living Shoreline Project over one year and placed those assemblages within the broader historical context of Lake Pontchartrain. Monthly sampling was conducted at the living shoreline and an adjacent riprap control site using seines, cast nets, and minnow traps. Fish assemblage structure was not significantly different between sites. …

A Comparison Of Ahdrift And Pitfall Traps For Surveying Small Vertebrates, Gabrielle Risko

All-Inclusive List of Electronic Theses and Dissertations

Understanding species occupancy is necessary to inform wildlife management and conservation decisions. To minimize the invasiveness of occupancy studies, some wildlife researchers have deployed game cameras to detect the presence of small vertebrates instead of utilizing stressful traditional live-capture methods. The Adapted Hunt Drift Fence Technique (AHDriFT) is an increasingly popular method for modifying and deploying camera traps to detect small vertebrates; however, no studies have directly compared AHDriFT to traditional pitfall traps operating at the exact same time, even though both are deployed along drift fences to capture small vertebrates. I compared these two methods (pitfall trapping and AHDriFT …

Reconstruction Of Copepod Populations In Sierra Nevada Lakes Using The Diatom Fragilaria Cyclopum, Rorie Reisner

All-Inclusive List of Electronic Theses and Dissertations

Copepods are one of the most abundant types of zooplankton, and their populations are often a vital part of the food chain, but their past populations cannot be estimated from lake sediments because their exoskeleton usually does not fossilize. Gull Lake is a glacial lake located in the subalpine region of the Sierra Nevada, California, which stands out due to the presence of the diatom Fragilaria cyclopum, which is rarer in diatom assemblages. Fragilaria cyclopum exclusively grows on copepods in lakes. Diatoms have an opaline silica skeleton that often fossilizes in lake sediments, so we can use this relationship with …

Reconstructing Stand-Age Structure In A Wet Miombo Woodland Using Dendrochronology, Zambia, Clara Tiyembekeze Zulu

All-Inclusive List of Electronic Theses and Dissertations

Dendrochronological research in tropical Africa has remained limited, leaving critical gaps in stand-age structure and climate-growth relationships in seasonally dry tropical woodlands. This study reconstructed stand-age structure and assessed climate sensitivity in the wet Miombo woodland of African Explosives Limited (AEL) forest, Copperbelt Province, Zambia. Field sampling was conducted during four African Dendrochronology Fieldschools (2021-2024) using a Modified Variable Area Transect (MVAT) design across nine plots. The series intercorrelation was 0.351; the average mean sensitivity was 0.423. The oldest tree was 170 years old, and more than 70% of the sampled species showed potential for dendrochronology. Markhamia obtusifolia was the …

Watershed Amendments: Assembling New Pervious Ground From Landscape Waste, Sophie Kaplan-Bucciarelli

Masters Theses

In Providence, Rhode Island, much of the downtown area is built over a vast historic tidal estuary. Though we no longer see the salt marshes, wooded bluffs, or meadows that once characterized this landscape, we recognize their absence in contemporary crises of urban heat, flooding, polluted soils and stormwater runoff, and habitat loss. These conditions are particularly acute along the city’s industrialized river corridors, where vacant lots and parking areas sit idle, their history paved over and potential constrained by limited imagination and resources.

These lots - already experiments in fill and land building after centuries of disturbance - can …

Reassembling Riparian Ecosystems: Stream Restoration Effects On Vegetation, Arthropods, And Aquatic-Terrestrial Connectivity, Katelyn P. Driscoll

Biology ETDs

Riparian areas exist at the aquatic-terrestrial interface and provide disproportionate ecosystem services, yet multiple stressors have degraded these zones globally. Stream restoration seeks to reverse degradation, but rigorous evaluation of treatment effectiveness remains limited. I conducted a before-after-control-impact (BACI) study in the southern Rocky Mountains to evaluate two stream restoration treatments—beaver dam analogs (BDAs) and plug-and-ponds (P&Ps)—across three dimensions of riparian ecosystem response. Using Bayesian analysis, I quantified treatment effects on functional diversity and composition of riparian plant communities. Using generalized linear mixed models, I evaluated restoration effects on riparian arthropod abundance, richness and guild composition across lateral gradients and …

From Flight To Hatching: Adult Sexual Dimorphism, Life History, And Egg-Stage Ecology Of Pseudocotalpa Giulianii, Mandylene Mountain

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Nevada endemic dune beetle Pseudocotalpa giulianii is currently known only from two dune systems in Amargosa Valley, Nevada, yet much of its life cycle occurs below the sand surface and remains poorly documented. This thesis addresses key gaps in adult-stage biology and egg-stage development that are relevant to understanding reproduction, vulnerability, and habitat requirements in this dunerestricted species.

To characterize adult sexual dimorphism and life history, I quantified morphological differences between males and females and measured sex-specific adult survival under laboratory conditions relative to the aboveground flight season. Males and females overlapped broadly in external body size, but tarsal …

Thermal Physiological Ecology Of The Relict Leopard Frog At Hot And Cold Springs, Robert P. Pelletier Iii

UNLV Theses, Dissertations, Professional Papers, and Capstones

The relict leopard frog (Rana onca) once ranged across drainages in southern Nevada, northwestern Arizona, and southwestern Utah. Following a decline, the species only persisted in a few geothermally influenced hot springs, which led to the perspective that hot springs were high-quality habitat. Rana onca has been under intensive, multiagency management and the species has been translocated to establish additional populations, including at cold-water sites. Three research studies are presented into the thermal physiological ecology of R. onca with the aim of informing conservation strategy. The research was focused at a thermally influenced hot spring and a cold-water spring to …

Impact Of Land-Use Disturbances On The Composition Of Wetland Plant Communities Across The Conterminous United States, Maya Merchant

Undergraduate Honors Theses

Due to the threat of invasive species on wetland biodiversity, it is critical to assess factors driving their proliferation in wetlands. To address this growing need, this project analyzes relationships between non-native species and known anthropogenic disturbance types associated with increased biological invasions. Using the U.S. EPA’s 2021 National Wetland Condition Assessment, the relationship between non-native species (diversity, richness, and coverage) and surrounding land-use within 500, 1,000, and 3,000-meter buffers was evaluated. To explore patterns across larger spatial scales, mean non-native species diversity, richness, and coverage was calculated at the watershed level and compared to associated percentages of agricultural land …

Distribution, Habitat, And Fish Assemblages Associated With The Rocky Shiner In Arkansas, Savannah L. Wise

ATU Theses and Dissertations 2021 - Present

The Rocky Shiner (Notropis suttkusi) is a minnow species endemic to the Red River and its tributaries in southern Arkansas and Oklahoma. This species is petitioned for listing under the Endangered Species Act and is a species of greatest conservation need (SGCN) in Arkansas. However, there is little information for the species’ distribution, habitat use, and ecological niche, especially within the Arkansas portion of its range. Because of this data gap, my study provides an updated description of its distribution and habitat associations using conditional occupancy modeling and explores patterns of species co-occurrence within the community. I sampled …

Ecological Responses To Living Shoreline Restoration, Aaron S. Bland

Graduate Theses and Dissertations (2019 - present)

Coastal built communities and natural coastal ecosystems face similar and interrelated hazards: shoreline sediment erosion, shoreline retreat, and worsening storms, each of which is exacerbated by relative sea level rise. Living shorelines are coastal defense projects that incorporate natural habitats to provide more sustainable shoreline defense and improve the coastal ecosystem. Living shorelines have been widely adopted, but their performance has been highly variable, and the mechanisms of project success and failure are unclear. The overarching goal of this dissertation was to better understand the ecosystem responses to coastal restoration, focusing on the primary habitats of coastal salt marsh and …

Bottles, Butterflies, And Biomass: Recycled Glass Sand, Microbial Additions, And Herbivory Effects On Milkweed Growth, Kealey Skinner

Honors Theses

Plant-soil-microbe interactions are integral components of ecological networks and drive ecosystem function from the bottom-up. Whereas herbivores regulate ecosystem function from the top-down, having opposing and potentially complementary effects on ecosystem function. My thesis sought to understand how below-ground microbial communities contribute to herbivore preference and plant biomass across varied soil substrates. My thesis asked: how do substrate and soil microbial communities influence herbivore preference and plant biomass accumulation on swamp milkweed (Asclepias incarnata)? To address this question, seedlings of A. incarnata were sown in 2.5 cm wide × 10 cm deep pots filled with either natural beach sand or …

Acute Effects Of The Psychoactive Pollutant Fluoxetine On The Antipredator Behavior Of The Gulf Killifish (Fundulus Grandis), Semyra Reus

Honors Theses

Pharmaceutical contaminants are increasingly prevalent in aquatic environments, yet their sublethal effects on ecologically relevant behaviors remain poorly understood, particularly in estuarine systems. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are of particular concern due to the conserved role of serotonin in regulating behavior across vertebrates. Here, we investigated how acute exposure to environmentally relevant concentrations of fluoxetine influences anti-predator behavior in Gulf killifish (Fundulus grandis), a key estuarine fish commonly found in saltmarsh habitats. Killifish were exposed to control (0 ng/L), low (17.8 ng/L), and high (596 ng/L) fluoxetine concentrations and subsequently tested in the presence …

Bugs, Birds, Blue: Queer Ecologies Of Embodiment, Kinship, And Survival, Celeste B. Newcomb

Theses and Dissertations

bugs, birds, blue is a multi-channel audiovisual installation that examines queer ecology as a framework for understanding transgender embodiment, kinship, and survival amid environmental crisis and ongoing political attacks on trans life (Mortimer-Sandilands and Erickson). Through sculpture, projection, sound, reflective surfaces, and biological imagery, the installation places human bodily matter alongside microbial and aquatic life forms to challenge narratives that frame trans existence as unnatural, recent, or isolated. Instead, the work proposes transness as relational, adaptive, and deeply entangled with broader ecological systems. The installation is composed of two interconnected environments. On one side of the space, three aquariums rest …

Feeding Ecology In Coastal Systems, Randi L. Cannon

Graduate Theses and Dissertations (2019 - present)

Oysters (Crassostrea virginica) are critical foundation species in estuaries, providing numerous ecological and economic benefits. However, oyster populations have diminished worldwide. Effective oyster restoration and aquaculture require a mechanistic understanding of the physiological and environmental factors that govern oyster feeding, growth, and resilience under changing coastal conditions. We investigated how oyster ploidy and environmental conditions influenced oyster feeding and investigated how changes in abiotic conditions affected behavioral performance of oyster drills (Stramonita spp.), a key oyster predator. To better understand feeding responses and behaviors of both predator and prey we 1) used in-situ filter feeding assays to determine if feeding …

Enhancing Walleye (Ogaa) Recruitment: Evaluating Assisted Reproduction As A Mitigation Strategy, Douglass Keiser

Biology Graduate Theses

Over the past several decades, cold- and cool-water fish populations across the Upper Midwest, including Minnesota and Wisconsin, have shown troubling signs of decline. Among the most affected is the walleye/Ogaa (Sander vitreus), a species deeply embedded in the ecological balance, cultural identity, and economic vitality of the region, and central to the lifeways, treaty-reserved rights, and resource stewardship of Tribal Nations, including Ojibwe communities across the Upper Midwest. Despite ongoing stocking efforts and harvest regulations, many lake systems have experienced persistent declines in natural recruitment, prompting resource agencies to investigate the underlying causes. One such system is …

Degradation And Metabolic Analysis Of Synthesized Quorum-Sensing Signals By The Model Eukaryote Chlamydomonas Reinhardtii, Adam Josef Bach

Theses and Dissertations

Bacterial organisms can “talk” with one another on a colony-wide scale using a communication system known as quorum-sensing (QS) via chemical signals. These signals are produced at a basal rate throughout the life of the bacteria and are classified as autoinducers, which diffuse across the cell membrane. Once the critical concentration is reached, they begin to diffuse back into the cell and initiate a phenotypic change. As these signals exist outside the membrane of their producer, they are also accessible to other organisms. It has already been noted that some plant species uptake these compounds through their roots and break …

Forest Overstory Mortality & Recruitment Patterns Eight Years Following Wildfire In The Southern Appalachians, Ruth Cumberland

All Theses

In this study, we investigated patterns of forest overstory mortality and recruitment eight years after wildfire in a large wildfire site the Southern Appalachians, a topic that has not been thoroughly investigated to date. With evidence that pre-fire drought promotes post-fire mortality through impaired physiological function and increased fuel consumption, unknown patterns following wildfire are important to study under shifting climate and land-use conditions. In Chapter 1, three areas of interest were investigated: (a) functional group mortality response to wildfire effects, (b) temporal differences in early (1-3 years) and late (5-8 years) periods of delayed forest overstory mortality patterns following …

Twenty-Four-Hour Intermittent Fasting Extends Lifespan At The Expense Of Fecundity In Daphnia, Meridith L. Smith

Undergraduate Honors Theses

Dietary restriction (DR) is a well-established intervention for extending lifespan, yet the specific efficacy of intermittent fasting (IF) and its associated trade-offs remain under-explored in many Daphnia magna. This study investigated the effects of three IF intervals—2h, 24h, and 48h—on the longevity and fecundity of two clones of Daphnia. We hypothesized that longer fasting intervals would significantly extend lifespan at the cost of reproductive output, consistent with the disposable soma theory of resource allocation.
Our results demonstrate that 24h IF significantly increased longevity relative to ad libitum controls, even outperforming caloric restriction (CR) by reducing late-life mortality. In …

Emerald Bowfin Amia Ocellicauda Ecology In Three Minnesota Lakes: Abundance, Age Analysis, Diet Composition, And Stable Isotope Food Web, Griffin Blegen

Biology Graduate Theses

The Emerald Bowfin Amia ocellicauda is a predatory fish species native to Minnesota that has often been discriminated against. This research expands ecological knowledge of Bowfin in Minnesota and provides population data to guide future management. Bowfin were sampled in the spring of 2024 and 2025 and a multi-census mark–recapture model was used to estimate abundance in three lakes. Estimated populations were 196 individuals in Little Toad Lake (95% CI: 116, 242) or 4.4 fish/littoral ha (95% CI: 2.7,5.7), 657 in Lake Sarah (95% CI: 436, 1014) or 4.2 fish/littoral ha (95% CI: 3.0, 6.7), and 612 in Gun Lake …

Variable Hybridization Rates Between F2 Fundulus Notatus Females, Jordan Tanaka

Honors Theses

Hybridization between two related species has been widely observed and offers a lens into complex evolutionary processes. Endogenous and exogenous factors affect hybrid fitness and diversification, and pre-zygotic and post-zygotic barriers affect species’ ability to hybridize. Female mate choice is a pre-zygotic isolation mechanism which is known to be more significant than male mate choice in many species, a trend which is linked to females often investing more energy into offspring. Detailing the ways in which these mechanisms operate is integral to understanding hybridization on a larger scale. The species examined here, Fundulus notatus and Fundulus olivaceous, are closely …

Clay Minerals Do Not Influence Nitrous Oxide Production Via Denitrification In Simulated Oxygen Minimum Zones, Luke Rein

Dartmouth College Master’s Theses

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It has been proposed that export of organic carbon from the epipelagic zone to the seafloor can be increased by the addition of 20 mg L^{-1 …}

Hfpo-Da Aquatic Toxicity And Bioaccumulation, Bailey Dawn Rappold

Theses, Dissertations and Capstones

Per- and polyfluoroalkyl substances (PFAS) have been detected globally in environmental media and biota. Legacy compounds PFOA and PFOS have been observed to be toxic and bioaccumulative in low doses and have been removed from production and industrial processes. Replacement PFAS chemicals are less understood and present a gap in current knowledge in their toxicological effects. This research utilized extended chronic toxicity studies to assess the impacts of HFPO-DA, a short chain replacement PFAS, on the standard aquatic toxicology organism Pimephales promelas. Organisms were exposed for 29 to 30 days at environmentally relevant concentrations of the toxicant, 7.8125 ng/L …

Temporal Avoidance By Gray Foxes Reflects Growing Pressure From Expanding Coyotes In The Neotropics, Madison Odenbach

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Coyotes (Canis latrans) are rapidly expanding their range towards South America, potentially threatening the world’s highest canid diversity residing on that continent. A better understanding of their interactions with native species is needed to anticipate potential competitive impacts. In Costa Rica, native gray foxes (Urocyon cinereoargenteus) likely occupy a similar niche to the coyote newcomer, yet little data exists on their interactions in tropical ecosystems. We hypothesized the two species separate temporally to minimize the potential for competition in our study area, given preliminary data suggesting high spatial overlap (57.1% of coyote-detected sites overlap with fox-detected …

Using Genetic Analysis To Infer Familial Relationships Of Westslope Cutthroat Trout In The Lower Priest River, Idaho, Kolby Emtman

EWU Masters Thesis Collection

The Westslope Cutthroat Trout (Oncorhynchus lewisi) is a native species of salmonid that holds both cultural and ecological significance in the Idaho Panhandle region of the United States. Within this region, the Priest River is a major contributor of migrant Westslope Cutthroat Trout to the Clark Fork Pend Oreille basin. This study aimed to estimate the proportion of juveniles that have at least one migrant parent, illustrate gene flow using juvenile half sibling relationships, and showcase varying levels of spawning success using juvenile full sibling relationships. Sampling of juvenile individuals occurred in 11 tributaries of the Priest River over …

Assessing Forest Health And Small Mammals After A Limited Suppression Wildfire In Colville National Forest, Samantha J. Kennel

EWU Masters Thesis Collection

In the face of a wildfire crisis, there is a growing need to expand the pace and scale of forest treatments, including the strategic use of wildfire as a management tool. However, ecological outcomes remain uncertain in forests shaped by more than a century of fire suppression. The 2022 Thor Fire, a managed wildfire in the Colville National Forest, Washington, provides an opportunity to evaluate forest health in a relatively understudied system. Using a control–impact design, I established 100 monitoring plots in burned and adjacent unburned forests to assess how wildfire and fire severity influence forest structure, fuels, and tree …