Digital Commons Network^™

Temporal Trends In Dryland Soil Carbon Fluxes In Response To Artificial And Natural Pulsed Moisture Events, Briana Alyce Salcido

Open Access Theses & Dissertations

Critical zone processes in drylands play a crucial role in the global carbon cycle, and one of the most important processes is soil CO2 efflux at the interface between soils and the atmosphere, which represents a main pathway for loss of carbon. Predicting the carbon dynamics at this interface is challenging due to the complexity of belowground processes, which include both biotic (soil respiration) and abiotic (calcite precipitation) production of CO2, as well as transport processes that include both diffusive and advective components. In this study, we aimed to investigate the contribution of soil air displacement to soil CO2 efflux …

Effect Of Elevated Temperature And Roundup Exposure On Oxidative Stress And Antioxidant Status In The American Oyster, Afsana Chowdhury

Theses and Dissertations

Aquatic organisms are frequently exposed to various environmental stressors. In this study, we observed the short-term (1-week) combined dose-dependent effect of Roundup, a glyphosate-based herbicide, and high temperature (30°C) on the morphology of gills and digestive glands, expression of heat shock protein-70 (HSP70), dinitrophenyl protein (DNP), nitrotyrosine protein (NTP), antioxidant enzymes such as catalase (CAT) and superoxidase dismutase (SOD) in tissues of American oyster (Crassostrea virginica). Histological analyses showed an increase in mucous production in the gills and digestive glands, hemocyte aggregation in the connective tissues as well as structural change of the lumen in the digestive glands …

Long-Term Spatial And Temporal Assessment Of Criteria Air Pollutants Concentration Trends In The Lower Rio Grande Valley Region Of Texas, Usa, Md Salahuddin Majumder

Theses and Dissertations

Air pollution is a substantial environmental challenge all over the world. This study investigated the long-term air pollution levels in the Lower Rio Grande Valley region, by utilizing data collected from five continuous ambient monitoring stations in two counties over 23 years, from January 2000 to December 2022, to analyze daily, monthly, and seasonal variations of different pollutants, including ground-level ozone, particulate matter, and carbon monoxide. This study also identified distinct daily and seasonal patterns for O3, PM2.5, PM10, and CO at each monitoring site, influenced by factors such as traffic emissions, temperature, solar radiation, indoor heating, and weather conditions. …

A Programmatic Geographic Information Systems Analysis Of Plant Hardiness Zones, Andrew Bowen

Electronic Theses and Dissertations

The Plant Hardiness Zone Map consists of thirteen geographical zones that describe whether a plant can survive based on average annual minimal temperatures. As climate change progresses, minimum temperatures in all regions are expected to change. This work programmatically evaluates predicted future climate projection data and converts it to United States Department of Agriculture-defined hardiness zones. Through the next 80 years, hardiness zones are projected to move poleward; in effect, colder zones will lose area and warmer zones will gain area globally. Some implications include changes in crop growing degree days, which could alter crop productivity, migration and settlement of …

Optimal R&D Investment In The Management Of Invasive Species, William Haden Chomphosy, Dale T. Manning, Stephanie A. Shwiff, Stephan Weiler

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive alien species (IAS) threaten world biodiversity, ecosystem services, and economic welfare. While existing literature has characterized the optimal control of an established IAS, it has not considered how research and development (R&D) into new removal methods or technologies can affect management decisions and costs over time. R&D can lower the costs of control in a management plan and creates an intertemporal trade-off between quick but costly control and gradual but cheaper removal over time. In this paper, we develop and solve a continuous time dynamic optimization model to study how investment in R&D influences the optimal control of an …

Investigation Of Microplastics In River Bottom Sediment Along The Musconetcong River, Nicole Perkins

Theses, Dissertations and Culminating Projects

The knowledge of microplastics remains limited since there are scientific challenges in understanding long-term effects and health risks associated with microplastics in all environments. Challenges associated with microplastics investigations include limited approaches to microplastics sampling and analyses, understanding long‐term behavior of microplastics, the organismal and ecosystem health risks, and finding alternatives to using plastic. The research on microplastics has focused mainly on microplastics abundance and distribution in the environment, while their transport and pathways have remained rather understudied. The goal of this study was to expand our knowledge of microplastics in river sediment.

This microplastics investigation consisted of sampling the …

Rattus Norvegicus As A Biological Detector Of Clandestine Remains And The Use Of Ultrasonic Vocalizations As A Locating Mechanism, Gabrielle M. Johnston

Master's Theses

In investigations, locating missing persons and clandestine remains are imperative. One way that first responder and police agencies can search for the remains is by using cadaver dogs as biological detectors. Cadaver dogs are typically used due to their olfactory sensitivity and ability to detect low concentrations of volatile organic compounds produced by biological remains. Cadaver dogs are typically chosen for their stamina, agility, and olfactory sensitivity. However, what is not taken into account often is the size of the animal and the expense of maintaining and training the animal. Cadaver dogs are typically large breeds that cannot fit in …

Predictive Ecology And Management Of Phyllosphere Microbial Communities Through Cross-Scale Synthesis, David W. Armitage, Morgan E. Carter, Robin A. Choudhury, Mitja Remus-Emsermann, Cindy E. Morris, Johan H. Leveau, Linda L. Kinkel, José Pablo Dundore-Arias

School of Earth, Environmental, & Marine Sciences Faculty Publications

Here we summarize the main takeaways from a symposium and hybrid virtual and in-person participatory discussion focused on the challenges of scale in understanding the ecology and management of phyllosphere microbial communities. We provide an overview of the confounding effects of spatial scale on inference in microbial ecology, the spatial organization of microbial interactions in the phyllosphere, advances and remaining gaps in measuring phyllosphere colonization across scales, and the epidemiology in the phyllosphere. We hope to motivate further discussion and the development and adoption of creative approaches to solving the challenges of scale to enhance fundamental understanding and practical management …

Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris

All Theses

Since the 1950s, the United States has produced approximately 90,000 metric tons of spent nuclear fuel (SNF) (Office of Nuclear Energy, 2022); however, no long-term storage solutions are available. Technecium-99 and neptunium-237, two fission products found in SNF, readily form highly mobile species in oxidizing conditions (Hu, 2008; Bondietti, 1979) and have respective half-lives of 2.13 x 10⁵ and 2.14 x10⁶ years (Hu, 2010). Considering these characteristics, ⁹⁹Tc and ²³⁷Np are two risk-driving isotopes found in SNF storage. The process of macropore-facilitated preferential flow, transport through cracks within a soil matrix, has been recognized to increase …

Determination Of Cadmium Uptake In Crassostrea Virginica Shell Under Controlled Conditions, Joseph John Pavelites Ii

Graduate Theses and Dissertations (2019 - present)

The objective of this thesis was to meet growing demand for the development of environmental biomonitors that protect ecosystems and public health. To do this, I determined the potential of oyster shell as a bioindicator of cadmium (Cd) in the environment by determining the mode of Cd uptake and relationships between Cd concentrations in the environment, shell, and soft tissues of juvenile eastern oysters (Crassostrea virginica Gmelin). I performed a review of the literature on the ability of oyster shell to retain metal contaminants and the factors that could affect this process (Chapter 2). I then reared C. virginica …

Amazon Deforestation And Its Effects On Local Climate, Andrew Baker

Department of Environmental Studies: Undergraduate Student Theses

The Amazon has been faced with extensive deforestation beginning in the 1960’s mainly for the purpose of cattle ranching and agriculture, as well as logging and mining making up smaller but noticeable portions. This rainforest is a place rich in its biodiversity of plants and animals, and until recently it was also one of the planet’s largest natural carbon sinks. This is important to help offset anthropogenic carbon emissions that are accelerating climate change, but because of the land use changes it has been subjected to, it has become another source of carbon release. This study aims to determine what …

Regenerative Agriculture: A Pathway For Addressing Nebraska’S Water Quality And Soil Degradation Challenges, Kjersten Hyberger

Department of Environmental Studies: Undergraduate Student Theses

It is important to begin this thesis by acknowledging that the State of Nebraska is on stolen Native land. Furthermore, the University of Nebraska is a land-grant university that was ultimately given 89,920 acres of Native lands for the paltry sum of $11,194. To date, the University of Nebraska has benefited from a 51:1 profit ratio on the funds raised from its 1873 land grant, raising over $500,000 in endowment principle. I humbly acknowledge that the privilege of earning my degree at UNL came through the often violent and bloody displacement of multiple tribal nations (High Country News, 2020).

Place-Based Pedagogies In Post-Secondary Science Education: A Scoping Literature Review, Megan Swain

Department of Environmental Studies: Undergraduate Student Theses

How do we connect students to a class and how do educational professionals create those connections? What makes an educational experience memorable? How do we cultivate students who are passionate and engaged? These are all important questions in educational fields and ones that have increasing importance in a world of growing virtual education. This thesis aims to look deeper into one method, place-based education that attempts to answer some of these questions.

Place-based education (PBE) is a pedagogy that utilizes the local physical environment and community as an educational tool. Educators focus lessons on places, people, and things surrounding their …

Regeneration Of Quaking Aspen And Understory Vegetation Change After Fire Risk Reduction Treatment, Allison M. Trudgeon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaking aspen (Populus tremuloides Michx.) is a keystone species that, when coexisting with conifers (i.e., seral aspen), often undergoes stand-replacing disturbances to sustain long term vigor. Historically, mixed-to-high severity fire reduced fuels and regenerated aspen, but such disturbances have become less common in recent decades. This has often led to high fuel loading, and many seral aspen stands are at now risk of an unpredictable, high-severity fire, posing a threat to development in the wildland-urban-interface. The lack of a commercial market for aspen, and the risk of conducting prescribed fire, means there are few alternate management options. This has …

Outside, Looking In: A Dissertation On Mindful Walking And How Green Exercise Affects State Mindfulness And Connectedness To Nature, Dustin Wyatt Davis

UNLV Theses, Dissertations, Professional Papers, and Capstones

INTRODUCTION: Mindfulness, green exercise, and connectedness to nature are increasingly popular topics among academics and the public. These three topics overlap in the underexplored area called mindful green exercise. Mindful green exercise is a blend of mindful exercise and green exercise. Mindful exercise is physical exercise during which people pay attention on purpose without judgment to each new present moment. The person applies an accepting awareness to internal phenomena (thoughts, emotions, and bodily sensations) and external phenomena (objects and events in the environment). Green exercise is exercise performed outdoors in natural environments. Despite its name, green exercise does not only …

Desert Spring Prokaryotes And Benthic Macroinvertebrates: Geological And Ecological Controls, Ariel D. Friel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Desert springs are aquatic oases, being considered among the most diverse and imperiled ecosystems on Earth. Despite the ecological significance and threatened status of desert springs, few studies have surveyed the microorganisms in these systems or their interactions with other community members. The primary goal of this dissertation was to describe the major controls influencing the community ecology of prokaryotic and BMI communities in cold- and moderate-temperature desert springs of the southern hydrographic Great Basin. Chapter 1 provides a broad overview of spring ecosystems and of each chapter included in this dissertation. Chapter 2 documents the first-ever, regional-scale survey of …

Study Of Trace Elements In Southern Nevada Spring Waters And Lakes, Hyejeong Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Comprehending the natural water resource is imperative for the entire state of Nevada and of particular significance for Southern Nevada, where rapid population growth and climate change are placing significant strain on supplies. This research underscores the significance of water chemistry in identifying potential water source areas through trace elements. For the first time, the study proposed measuring the compositions of the entire suite of metal elements, ranging from Li to U, in over 40 springs in the Moapa Valley and its upper gradient valleys, utilizing the iCAP Qc ICP-MS (Inductively Coupled Plasma Mass Spectrometer) at UNLV. The research evaluated …

A One-Dimensional Analysis Of A Microbial Fuel Cell For Efficient Acetate Removal And Power Density Output, David Rouhani

UNLV Theses, Dissertations, Professional Papers, and Capstones

Microbial fuel cells (MFCs) are electrochemical devices that utilize microorganisms to convert organic matter into electrical energy. MFCs have been discussed to have potential application for sustainable wastewater treatment due to their ability to generate electricity while simultaneously treating contaminated water. To optimize MFC performance, numerical models can be used to understand the complex electrochemical and biological processes occurring in the system. In this study, a numerical model was developed to simulate the performance of MFCs under varying operating conditions and to investigate the performance of a MFC for treating wastewater fuel. More specifically, the MFC was modeled to oxidize …

The Effects Of Habitat Isolation On Fine-Scale Genetic And Geographic Structure Of Populations Of Two Threatened Endemic Insects In Southern Nevada, Pseudocotalpa Giulianii And Icaricia Shasta Charlestonensis, Kristen Tovar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Assessing the role geographic isolation and ecological specialization have on phylogeographic patterns contributes to our understanding of the evolutionary history of a species and the processes that erode genetic diversity. I used mitochondrial and nuclear genomic sequences to assess whether habitat isolation has shaped the fine-scale patterns of present-day genetic structure and diversity in two threatened insect species endemic to southern Nevada. Pseudocotalpa giulianii (Coleoptera; Scarabaeidae) is a dune obligate scarab beetle endemic to only two small, isolated sand dunes in Nye County, Nevada, with a usable habitat of less than 4.2 km sq that is impacted by on-going degradation. …

Investigating Haloacetonitrile (Han) Formation Potential From Nitrogenous Antibiotics And Agrochemicals, Kazi Shafayet Haider

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disinfection can promote safe drinking water. Chlorine and chloramines are the two most used disinfectants. While these disinfectants are effective in inactivating disease-causing pathogens, they also produce hazardous byproducts when they react with organic compounds (precursors). Nitrogenous disinfection byproducts (N-DBPs) are more toxic than their counterparts. The increased use of nitrogen-based agrochemicals and antibitics has led to their detection in different water sources. The presence of secondary amine and aniline in these compounds can act as a source of reactive nitrogen to form N-DBPs. In addition, the increased concentration of bromide in water systems due to anthropogenic activities can enhance …

Effects Of Landscape And Yard Features On Mammals In Residential Yards In Northwest Arkansas, Emily Johansson

Graduate Theses and Dissertations

The human footprint is rapidly expanding, and wildlife habitat is continuously being converted to human residential properties. Most wildlife residing in developing areas are displaced to nearby undeveloped areas. However, some animals can coexist with humans and acquire the necessary resources (food, water, shelter) within the human environment. This may be particularly true when development is low intensity, as in suburban yards. Due to the wide variety in how homeowners utilize their yards, they can be considered individually managed “greenspaces.” These yards can provide a range of food (e.g., bird feeders, compost, gardens), water (bird baths and garden ponds), and …

Cross-Boundary Stewardship In Protected Area Centered Ecosystems: Perceptions Of Success And Characteristics Of Cooperative Engagement, Ryan D. Tarver

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The legal boundaries of protected areas, such as national parks are established and enforced by humans. Therefore, jurisdictional boundaries are ultimately have human meaning but not necessarily ecological relevance as natural phenomena such as watersheds and wildlife habitat often extend beyond a jurisdictional boundary. When considering the extent of natural system, we find that protected areas only make up part of a given ecosystem. The result is a large expanse of lands that fall under a various ownership types that include both publicly and privately designated tracts of land. This presents a management challenge when attempting to manage at the …

An Overview Of Serial Depletions Of Global Marine Fisheries 1950 To 2019, Alison Follmer

Biological Sciences Undergraduate Honors Theses

Overfishing is a global issue that poses a significant risk to the entire ocean ecosystem in diminishing biodiversity and ecosystem function. This thesis examined the pattern and pace of fisheries depletions due to commercial fishing during the past 70 years. The Food and Agriculture Organization of the United Nations (FAO) Division of Fisheries and Aquaculture maintains a database of global hauls of marine taxa (reported in metric tonnes) from 1950 – 2019. These data were queried to determine the total number and sequence of fisheries depletions documented by the historic record. Analysis of this database showed progressive, linearly-increasing exploitation of …

Ecological Natural Restoration And Its Artificial Promotion Mode In Coal Mining Area, Liu Wei, Yin Qinrui, Liu Xianghong

Coal Geology & Exploration

The natural ecological restoration is an important direction of the national ecological restoration policy. Taking limited artificial measures to promote the natural ecological restoration in coal mining areas is in line with the actual engineering requirements under the context of "double carbon" goal and thus has a better prospect in market application. Herein, the research results in terms of natural ecological restoration were sorted out systematically for the three main types of damaged land in the coal mining areas. Meanwhile, the concept connotation of artificial promotion of natural restoration was studied and analyzed. Besides, the governance mode by zone and …

263 - Housing And Integrating Bats Into The Suny Geneseo Campus Ecosystem., Hailey Cullen, Gabrielle Joseph

GREAT Day Posters

This presentation centers on research conducted on building a sustainable prototype design of a bat box. We focused on configuring the implementation of bat boxes around the SUNY Geneseo campus as well as the optimal materials to use in the building of this prototype. The primary species targeted in our research and design development is the big brown bat.

Alleviating Environmental Stresses In Native Arkansas Plants By Arbuscular Mycorrhizal Fungi Inoculation, Rebecca C. Morse

ATU Scholars Symposium

The rapid human-driven changes in the environment during the Anthropocene have placed extreme stress on many native plants and animals. Beneficial interactions with microorganisms may be crucial for ameliorating these stressors and facilitating the ecosystem services host organisms provide. The role of an important mutualistic association with arbuscular mycorrhizal fungi (AMF) in the competitive ability and successful adaptation of Arkansas native species by enhancing nutrient uptake has not been previously considered. Analysis of field root and soil samples from the native species in their native range as well as a controlled greenhouse experiment will be conducted to determine the level …

Environmental Factors Affecting Coleoptera Biomass In The Ozark Mountain Range In Arkansas, Hayley J. Springsteen

ATU Scholars Symposium

Abstract:

Terrestrial invertebrates including species of Coleoptera (beetles) play an important role in many ecosystem services including soil formation and fertility, pollination, decomposition and nutrient turnover, population regulation of other organisms through predation. Coleoptera are often vital in determining biodiversity and conservation techniques. The purpose of this study is to contribute to the knowledge of how environmental factors and different management practices are affecting Coleoptera populations and further assist ecologists in improving management techniques in the future. The insect data in this study was collected over the course of two weeks in the Arkansas portion of the Boston Mountain range. …

Estimating Blue Carbon Stocks In Native And Non-Native Seagrass Beds Of Jobos Bay, Pr, Michael Chapman, Raven Winant, Kayla Gonzalez-Boy, Mark Mccarthy, Ángel Dieppa-Ayala

Symposium of Student Scholars

Seagrasses are keystone species that support coastal biodiversity, but not all species of seagrasses provide the same ecosystem services. Although seagrasses occupy a small area of marine habitat, they provide many ecosystem services. They stabilize sediments, remove nutrients, provide habitat and food for diverse marine life, and promote carbon storage in sediments. Jobos Bay is the second largest estuary in Puerto Rico and contains salt marshes, mangroves, and seagrass beds. The native seagrass, Thalassia testudinum, is the most abundant seagrass in the bay; however, a seagrass species from the Indian Ocean, Halophila stipulacea, began invading in recent years. The impacts …

Food Web Structure And Dynamics Across Space And Time, Angélica González

Sustainability Seminar Series

Human activities are fundamentally altering major biogeochemical cycles, which are at the core of the structure and functioning of Earth’s systems. Increasing inputs of chemical elements such as nitrogen (N) and phosphorus (P) and their imbalanced inputs (N:P ratios) are having severe consequences on ecological phenomena from organism physiology to ecosystem functioning. In this talk, I will discuss the utility of ecological stoichiometry thinking combined with the use of surveys, experiments, and data synthesis approaches, to understand the consequences of shifts in nutrient supply dynamics on ecological processes at multiple scales.

Balancing Interests In Forest Governance In Brazil And Indonesia, Annabel Mccormick Baldy

Environment and Sustainability Honors Papers

Forests play a major role in reducing levels of Greenhouse gasses which are a major contributor to global warming. Conversely, deforestation is a major contributor to climate change. This study examines the concept of good forest governance, dispelling notions that resource use needs to be a zero-sum game. Rather, it identifies local collective agreements as espoused by Elinor Ostrom in Governing the Commons as the best means of balancing the undeniable economic potential of converting forests to other uses (grazing, farming, and mining) with the more sustainable approach of protecting forests for their environmental benefit. For Ostrom, these collective agreements …