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Investigating The Response Of The Eastern Oyster (Crassostrea Virginica) To Low Dissolved Oxygen Conditions, Abiola Obafemi

Master's Theses

The Eastern oyster (Crassostrea virginica) requires dissolved oxygen (DO) of about 4 mg/L to support proper physiological function. Hypoxia and/or microxia occur when DO decreases to ≤ 2 mg/L. Salinity and temperature changes resulting from large-scale freshwater influx have been identified as key factors influencing the oyster populations in the Mississippi Sound. It is important to investigate the impacts of DO conditions on oyster mortality, biomass, size, and condition during these freshening events. Under controlled laboratory experiments, this thesis investigated 1) the response of oysters to microxic, hypoxic, and normoxic conditions 2) the response of oysters to combined hypoxia and …

Microbiome Assembly And Function In The Solitary Mason Bee, Osmia Lignaria (Megachilidae), Bailey Crowley

All Graduate Theses and Dissertations, Fall 2023 to Present

Animal-microbe interactions can influence host biology, ecology, and evolution. The assembly and function of microbes found within animal hosts oftentimes depends on which species are involved. Advances in sequencing technologies have permitted the exploration of host-microbe interactions in a variety of animals, including bees. Early research aimed at understanding the microbiomes of social bees, such as honey bees and bumble bees, found that microbes prevent the spoilage of stored pollen, breakdown indigestible nutrients into smaller molecules available for uptake by the host, and also protect the host from pathogens. When environmental stressors, such as increased temperatures, disrupt the microbiome, the …

The Effects Of Cover Crop Adoption On Yield Distributions Under Extreme Drought, Emory Johnson

Graduate Theses and Dissertations

Increased frequency and severity of extreme weather events due to climate change negatively impact agriculture output. Of particular concern is the adverse impact of droughts on corn and soybean yields, as these crops represent a significant portion of cash crop receipts in the United States. Cover crops are one practice that has gained attention due to their agronomic benefits and their potential to reduce downside production risk for producers. This study focuses on the impact of cover crop adoption on corn and soybean yields during drought conditions. We use cover crop adoption data from the Operational Tillage Information System, RMA …

The Role Of Mycorrhizal Associations In Modulating Poplar Growth, Phytohormone Responses, And Mortality Under Elevated Co2 And Temperature Conditions, Joshua Jr Frank-Webb

Electronic Thesis and Dissertation Repository

Climate change poses significant challenges to forests worldwide, particularly the Canadian boreal forest. Populus spp. are ecologically and economically important tree species that have had declining growth and survival due to elevated temperatures and droughts associated with climate change. Symbiotic microbes, such as mycorrhizal fungi, may increase plant growth under climate change conditions by altering tree metabolic profiles and increasing tree access to water and nutrients. My thesis explores the relationship between mycorrhizal fungi and a Populus hybrid (Populus x canadensis) grown under a range of future climate scenarios: ambient CO₂ (400 ppm) or elevated CO_{2 …}

Assessing The Use Of Regenerative Agriculture In California Almonds As Climate Change Resilience, Skyler M. Seamons

Master's Projects and Capstones

The agriculture sector is responsible for 10% of the United States’ greenhouse gas emissions. In turn, anthropogenic climate change threatens crops. With its Mediterranean climate, California is the country’s largest agricultural-producing state. Many California crops are at risk due to increasing temperatures and changed precipitation patterns. This paper investigates regenerative farming techniques as a tool to protect California crops from a changing climate. Almonds are used as a case study to analyze the soil management practices, finances, and policies underlying regenerative agriculture in California. A literature review and comparative analysis are used to compare regenerative and conventional soil management practices …

Climate Change And Environmental Crises In Coastal Cities: Charleston Vs New York City, Nolan Rodriguez

Student Theses 2015-Present

This paper addresses the increasing vulnerability that coastal communities face regarding climate crises and rising sea levels. Specifically, this paper investigates the environmental crises facing Charleston, South Carolina, and New York City. The geographical location of these cities places a more severe threat upon their environment, as opposed to urban collectives removed from the immediate effect of rising sea levels. A cross-examination of politics and economics is discussed in order to determine the causal relationship of each city’s engagement with its surrounding environment. This paper examines how each city is affected by climate change, what measures are in place to …

Ancient Wisdom, Modern Prosperity: Harnessing Traditional Ecological Knowledge To Revitalize Australia's Economy, Environment, And Human Wellbeing, Annabelle L. Baulch

Student Theses 2015-Present

This paper explores the traditional knowledge of Australia’s Indigenous people and how it can improve Australia's environment, health, and economic prosperity to shape a more sustainable future. Indigenous Australians managed the land for thousands of years; however, being forced off the land following European colonization resulted in terrible cultural, social, and environmental disruption for Aboriginal Australians and made conservation efforts difficult. Wildfires, imported species, mining, and agriculture is steadily destroying the Australian ecosystem, contributing to climate change, species extinction, and gaps in our cultural and ancestral knowledge. Chapter One overviews Australia's environmental issues; it uses quantitative data to explore the …

Reef Ecosystem Conservation For The Hawaiian Islands: The Impacts Of Ocean Warming And Acidification On Benthic Reef Populations, Samantha Roberts

Student Theses 2015-Present

This paper explores the anthropogenic effects of rapid climate change and ocean acidification on benthic coral populations along the Hawaiian archipelago. Moreover, the reliance of Hawaiian coastal communities on coral reefs for sustenance and economic prosperity is evaluated to determine the importance of reef ecosystem conservation for the prosperity of Hawaii. Chapter 1 introduces the importance of coral and supplies quantitative data on declining coral populations traditional to Hawaii, as a result of ocean warming and acidification. Empirical data from prior, prominent studies, combined with my own, will be discussed. Chapter 2 outlines the ecology of Hawaiian reef ecosystems, the …

Techniques And Trials In Pteridophyte Conservation And Cultivation, Jessica Bartel

Senior Theses and Projects

With the progressive nature of climate change conditions globally over the past century, there has been increasing focus on conservation of all species, but particularly those already endangered. Over 12,000 species of ferns live on Earth, and they do not produce seeds, so an investigation into their spores and how they reach maturity will allow us to preserve more genetic material in the future for these species. As a result, we investigated ex situ conservation and survivability of in vitro cultured gametophytes of within the genus Dryopteridaceae through herbarium sample germination rates across samples representing a wide age range ( …

Understanding The Effects Of Ocean Warming And Acidification On The Growth Of Marine Phytoplankton, Drajad Sarwo Seto

Electronic Theses and Dissertations

The concentration of CO₂ in the atmosphere, caused by human activities, has led to a rise in global temperature and an increase in surface ocean temperature. Moreover, the amount of CO₂ exchanged between the atmosphere and the ocean's surface alters the water's chemistry, decreasing pH. This phenomenon is known as ocean acidification (OA). The growth of marine phytoplankton is affected by environmental conditions, and the changes in ocean temperature and acidity are expected to impact their growth, ultimately affecting primary productivity in the ocean.

In my thesis, I explore how the growth of marine phytoplankton, including coastal diatoms, …

Assessing Equitable Distribution Of The Urban Tree Canopy At The Neighborhood Scale In Greenville, South Carolina., April Riehm

All Theses

We are living in an era that necessitates adaptation and resilience. The Earth is warming. Our climate has changed (EPA, 2016). Our planet is also rapidly urbanizing. It is predicted that 68% of people will live in cities by 2050. The City of Greenville is a rapidly growing city in South Carolina that has been losing its tree canopy to development(City of Greenville, 2023). The Urban Tree Canopy (UTC) is a community asset that provides many quality-of-life benefits including improved air quality, stormwater management, carbon sequestration, mental and physical well-being, increased mobility and access, aesthetics, a reduction in energy costs, …

Thermal Ecology And Swimming Performance Of Native Tadpoles Dryophytes Femoralis In Central Florida, Jessalyn Aretz

USF Tampa Graduate Theses and Dissertations

Urbanization and climate warming have contributed to global amphibian declines in recent decades. Amphibians are particularly vulnerable to climate and urban-induced warming because their physiological processes are dependent on temperature across all life stages, but few studies have been done on tadpole responses to warming in comparison to adult responses. The study objective was to determine how the thermal ecology and swimming performance of a native Florida tadpole varied with rearing temperature and urban level, and whether these traits are plastic or adaptive. We collected eggs from wild populations of pine woods treefrog (Dryophytes femoralis) tadpoles at an urban and …

Investigation Of The Effects Of Ocean Acidification On Juvenile Homarus Americanus Feeding Behavior, Sophia Roy

Honors Theses and Capstones

Climate change has led to increased CO2 absorption by ocean surface waters, resulting in decreased pH levels, a phenomenon known as ocean acidification (OA). A primary class of marine organism behavior is impacted by OA, in particular, olfactory-mediated behaviors related to foraging and feeding success. However, the biological mechanisms responsible for the documented impairment of foraging and feeding-related behaviors remains in question. We find that juvenile American lobsters (H. americanus) exhibit significantly faster rates of total feeding times in response to short-term low pH exposure. However, total search time and total handling time were not affected by pH when examined …

Measuring Nature’S Contributions To People Provided By Species In The Gulf Of Maine Rocky Intertidal Ecosystem, Madelyn L. Eippert

Honors Theses

Ecosystem services aim to quantify the value of nature provided to humans. However, Ecosystem services are typically measured at the level of the ecosystem as a whole and do not consider interactions between species in an ecosystem. Ultimately, the species in an ecosystem determine the services that are provided. Measuring ecosystem services at the landscape level misses the complex interactions and changing biodiversity of ecosystems. Currently, there is no accepted framework to link ecosystem services to species. In this thesis, I developed a framework to link Nature’s Contributions to People (NCP) to species. NCP includes 18 specific contributions (i.e. 18 …

Environmental Implications Of Modern Food Production: An Analysis For The Conscious Consumer, Jessica T. Coming

Cal Poly Humboldt theses and projects

This project explores the pathways by which agriculture affects the environment and determines which foods have the greatest climate, water, and land impacts. Agricultural effects on the environment are extensive, from loss of habitat and declines in regional biodiversity to disruption of global nutrient cycles and climate change. Global food production accounts for 26-34% of annual anthropogenic greenhouse gas emissions, makes up 38-46% of habitable land, and is responsible for 70% of freshwater extraction. The effect of agriculture on the environment is most significantly dictated by what type of food is being produced. Animal-based food products consistently have the highest …

Symbiosis Under Stress: Unraveling The Interplay Of Ocean Acidification And Rising Temperatures On Acropora Samoensis (Staghorn Coral), Jerald William Smolkin

Theses and Dissertations

This experiment explores the response of marine organisms to the combined challenges of ocean acidification and rising temperatures, with a focus on coral reef ecosystems. As global climate change threatens profound declines in coral reefs, understanding the multifaceted impacts of these stressors becomes crucial. The study observes cellular changes in A. samoensis tissues in four different groups, including control, Temp, pH, and Temp and pH. Results indicate significant breakdown of membrane compartmentalization and cell junctions, with notable degradation and calcium carbonate crystallization in pH-stressed samples. Additionally, chlorophyll extraction data support coral bleaching due to the expulsion of zooxanthellae. These findings …

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 …

Assessment Of Open Top Chambers To Simulate Effects Of Climate Change On Soil Temperature And Cover Crop Response In Agricultural Systems, Gretchen Bahmueller

Honors Theses and Capstones

Climate change is expected to yield warmer winters that have the potential to place additional stress on our already stressed agricultural systems. Understanding how agricultural systems may respond to these changes is essential to creating crop and land management plans that ensure food security for future generations. To better understand how warming winters can/will affect air and soil temperatures and cover crop performance, open top chambers (OTCs) were deployed post cover crop seeding in a field experiment at the UNH Kingman Research Farm in Madbury, NH. The experiment consisted of four cover crop treatments sown into or after corn: an …

Climate Change And Coastal Development Impacts On Oyster Abundances In Mosquito Lagoon, Fl, Emily Suchonic

Graduate Thesis and Dissertation 2023-2024

Live eastern oyster (Crassostrea virginica) reefs have declined by 62.6% in Mosquito Lagoon (ML) along the eastern Florida coast since 1943. While this species creates reefs by successive generations of oysters recruiting to conspecific shells, C. virginica can also attach to non-reef substrates including mangrove roots and armoring (e.g., seawalls), which may help counteract reef habitat loss. In recent decades, warmer winters have enabled red (Rhizophora mangle) and black (Avicennia germinans) mangrove expansion in subtropical salt marshes and temperate estuaries where oyster reefs occur. Additionally, 11.8% of ML's shorelines have been armored as of …

Forest Management In A Changing Climate: Integrating Social And Biopysical Sciences To Inform Adaptive Responses To Future Uncertainty, Peter Breigenzer

Electronic Theses and Dissertations

Forests provide numerous ecological and socio-economic benefits, yet climate change is creating novel and extreme conditions that threaten forests and disrupt traditional management practices. To address future uncertainty about how to manage forests amid a rapidly changing climate, researchers have developed adaptive management strategies that move away from using historical ecological baselines as management goals. However, despite increases in adaptive forest management frameworks, there are still concerns that private woodland owners (PWOs; also known as family forest owners or non-industrial private landowners) are not adopting beneficial practices. Additionally, since tree canopies often buffer understory microclimates (i.e., fine scale variation in …

Insights Into The Challenges Posed By Climate Change And Land Competition To Brazil’S Midwest Pulpwood Market, Roberto Hajime Sant Anna Kimura

Theses and Dissertations

I investigated the effect of climate change in one of the few expanding markets in the world in Brazil. In the last decades the demand for pulpwood increased from zero to 11 million tons, leading to an expansion of 700 thousand hectares of Eucalyptus plantation. In 2024, a new mill will start operating increasing the consumption of wood fiber by 8.2 million tons (+49%). I used mathematical programming to investigate how different scenarios of productivity and land will affect the market. My results showed that around 946,000 hectares (+124%) of additional timberland will be necessary in the upcoming decades. The …

Enabling Breeding For Fruitlet Freeze Tolerance In Peach, Ufuk Caglar

All Theses

Climate change is affecting the production of temperate fruit crops, with cold temperatures emerging as a critical abiotic stressor that limits plant growth and performance. Freeze damage, particularly in spring, has resulted in significant economic losses in peach production in the southeastern United States. Research efforts in peach and other Prunus species have primarily focused on studying dormancy-related traits associated with bloom time, such as chill and heat requirement, with fruitlet freeze tolerance not equally represented. Breeding for climate resilience in peach requires a combination of these traits to allow for late bloom via targeted chill requirement and high heat …

Linking Microbial Community Assembly In Flowers With Function Under Diverse Environmental Conditions: A Case Study Involving Erwinia Amylovora, Christopher Skylar Mcdaniel

All Graduate Theses and Dissertations, Fall 2023 to Present

Fire blight, a devastating disease of pome fruit trees caused by the bacterium Erwinia amylovora, can cause millions of dollars in losses for producers each year around the globe. Management approaches that involve use of antibiotics, such as streptomycin, can be effective; although concerns exist over pollinator and crop health when using them regularly. Recently, there have been developments that allow for biological agents such as microbes to curtail fire blight infection. These agents work by competing with Erwinia for resources or space, producing antibacterial compounds, or even killing Erwinia cells on contact. Unfortunately, these agents do not yet …

The Ecological Effects Of Nitrogen Enrichment In Aridlands, Jennifer Holguin

Open Access Theses & Dissertations

Anthropogenic nitrogen (N) deposition is one of the most prominent factors driving global change. Across the globe, N deposition has driven major changes in terrestrial ecosystems, such as declines in plant biodiversity, enhanced exotic plant growth, and changes to biogeochemical processes involved in carbon and nutrient cycling. While noteworthy effort has been put forth to investigate the effects of N deposition on terrestrial ecosystems, a disproportionate number of N addition studies have been conducted in temperate mesic systems. Thus, we lack a holistic and mechanistic understanding of how N deposition impact aridland ecosystems. Additionally, our predictions of the effects of …

Genomic Underpinning Of Drought-Associated Phenotypes In A Keystone Shrub Species Of Western North America, Carlos Dave Contreras Dumaguit

Boise State University Theses and Dissertations

Anthropogenic climate warming and habitat loss threaten species and ecosystem sustainability. Given this, it is urgent to determine whether populations can adapt at a rate sufficient to combat climate change or if human intervention is needed to preserve community ecosystem health. Assessing whether populations could adapt includes inferring whether key phenotypic traits associated to abiotic tolerance are under genetic control and therefore heritable. This thesis focused on the imperiled western North American sagebrush steppe and its widespread eponymous keystone species Artemisia tridentata, (common name, big sagebrush). To determine the adaptive capacity of any population, standing variation for phenotypic traits across …

The Effect Of Dietary Thiaminase On Cardiac Function And Morphology In Lake Trout (Salvelinus Namaycush), Peter Baker

Electronic Thesis and Dissertation Repository

Thiamine deficiency from the consumption of invasive, high-thiaminase prey fishes is considered to be a major barrier for lake trout restoration in the Great Lakes. In fishes, an understudied aspect of thiamine deficiency is its effect on cardiac function. I examined the effects of dietary thiaminase on cardiac function and morphology in lake trout, specifically as they relate to thermal tolerance. Two hatchery strains of lake trout (Seneca and Slate) were raised on a control or thiaminase diet for nine months. The thiaminase diet was associated with significant ventricle enlargement, impaired cardiac function, and reduced thermal tolerance; these effects were …

Improving The Land Trust Model’S Impact On Environmental Conservation In Northern California, Peter Talbot

Master's Projects and Capstones

For years, the land trust sector of California and much of the United States has operated with a dollars and acres mentality that has prioritized fundraising as a result of acreage protected. Within California, nearly 5.8 million acres of land have been protected by 132 land trusts throughout the state. To accommodate for the diverse cross-section of land and the many needs of the population, land trusts take on numerous shapes and sizes. A unique aspect of this diversity is the rich agricultural and natural spaces found throughout the state. This mix of land and variety of land uses has …

Illuminating The Drivers Of Genomic Diversification In Lamprologine Cichlids Of The Lower Congo River, Naoko P. Kurata

Dissertations, Theses, and Capstone Projects

Freshwater fishes are extraordinarily diverse, considering their available habitats represent a tiny proportion of the earth’s surface. Rivers connect heterogeneous habitats in a linear form and provide excellent simplified models to understand how aquatic biodiversity evolves. In particular, the lower Congo River (LCR) in west Central Africa consists of a dynamic hydroscape exhibiting extraordinary aquatic biodiversity, endemicity, and morphological and ecological specialization. This system is thus an excellent natural laboratory for understanding complex speciation and population diversification processes. In my research, I explore various drivers of diversification, and adaptive evolution in rheophilic lamprologine cichlids endemic to the LCR, including Lamprologus …

Physiological And Yield Responses Of Soybean Cultivars To Heat And Drought Stresses, Sadikshya Poudel

Theses and Dissertations

Soybean (Glycine max L.) is an important legume crop often exposed to heat and drought stresses during reproductive and early-seed setting stages, resulting in lower yields and seed quality. Ten soybean cultivars were phenotyped for individual (drought or heat) and combined stress tolerance. Under drought, reduced stomatal conductance and increased canopy temperature significantly reduced seed number (46%) and weight (35%). Heat stress alone reduced seed number (19%) and weight (23%) compared to control. Moreover, a degree increase in daytime temperature above 32 °C during the reproductive stage reduced seed weight by 4% and 7% under well-watered and drought conditions, respectively. …

Pasturelands As Natural Climate Solutions: A Socioecological Study Of Tree Carbon And Beef Production Trade-Offs, Bela Starinchak

Masters Theses, 2020-current

Forest restoration is the most effective natural climate solution, with the potential to sequester 37% of the carbon dioxide (CO₂) needed to reach the Paris climate mitigation goal. Cattle pastures offer an underutilized opportunity to increase global forest restoration efforts, improve biodiversity, and maximize carbon storage through the adoption of management strategies that prioritize the incorporation of trees into pasturelands. However, remote estimations of tree carbon storage in pastoral systems have never been field-verified and their accuracy is unclear. Furthermore, the effect of increased trees on cattle production is understudied across biomes. Lastly, the restoration potential of these …