Physical Sciences and Mathematics Commons^™

Rice Biomass Response To Various Phosphorus Fertilizers In A Phosphorus-Deficient Soil Under Simulated Furrow-Irrigation, Jonathan B. Brye

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Wastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH4PO4⋅6H2O), may provide a sustainable alternative to rapidly decreasing rock phosphate reserves. Struvite can be generated via chemical and/or electrochemical precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice cultivar (Gemini 214, RiceTec) grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)] in a P-deficient silt …

Navigating Murky Waters: State-Level Strategies For Wetland Preservation And Tile Drainage Regulation After Sackett V. Epa, Caleb M. Swanson

Honors Thesis

Wetlands are some of the world’s most valuable ecosystems, serving as provisioners of species habitat, carbon sequestration, flood mitigation, water quality purification, and other ecosystem services. Human development has resulted in substantial wetland loss the world over. In the 1970s, the United States Congress passed the Clean Water Act, giving the EPA broad authority over wetland protection. However, in the summer of 2023, the United States Supreme Court decided Sackett v. EPA, limiting the EPA’s jurisdiction over wetlands to those indistinguishably connected to generally recognized “Waters of the United States” and removing federal protection for millions of acres of wetlands, …

If You Build It, Will They Come? Assessing Habitat Quality For Marsh Birds At Created Marshes In Southeastern Louisiana, Katherine Aylett Lipford

LSU Master's Theses

Wetland loss occurs at an alarming pace globally, with extremely high rates along the northern Gulf of Mexico. Louisiana loses a football field of wetland every 100 minutes: that is 77,000 m² of wetland bird habitat lost daily. In Louisiana, marsh creation projects combat wetland loss, and while wildlife habitat is often used as a justification for restoration, wildlife receives little to no consideration during and after construction. Habitat characteristics such as site-specific hydrology, vegetation composition, and habitat structure affect the abundance of wetland birds and understanding these features is crucial to creating habitat that will benefit birds. My …

Fish Assemblage Structure In Great Lakes Coastal Wetlands Over Ten Years, Matthew S. Silverhart

Masters Theses

Coastal wetlands in the Laurentian Great Lakes are important habitats for many fish species. The geographic scale of the watershed and the diversity of land uses in the region result in substantial environmental variation among coastal wetlands. During 2011-2020, annual surveys were conducted as part of the Great Lakes Coastal Wetland Monitoring Program (GLCWMP) to better understand the status and trends of coastal wetlands. Fish sampling consisted of fyke netting in monodominant vegetation zones. During this time, 1225 unique monodominant plant zones in coastal wetlands were sampled, resulting in 584,125 fishes captured that consisted of 113 different species. Yellow Perch …

Coalescence: A Carnivore Coexistence Curriculum That Braids Indigenous & Western Ecological Knowledge Into A Relevant And Experiential Learning Opportunity For Youth, Stephanie Anne Barron

Graduate Student Theses, Dissertations, & Professional Papers

As grizzly bears (Ursus arctos horriblis) begin to reoccupy more of their historic range, and as humans and large carnivore populations continue to increase, incidences of human carnivore conflict are on the rise. A decolonial curriculum designed in collaboration with the Confederated Salish and Kootenai Tribe’s wildlife biologists stands to increase awareness of Indigenous ecological knowledge and teach youth about the importance of coexistence with carnivores. Additionally, this project could greatly influence youth perceptions of grizzly bears and other large carnivores. This research project examines the development and implementation of a carnivore coexistence curriculum for youth that is guided by …

Modern Colonialism: The Case Of Costa Rica And The United Fruit Company, Micah X. Perez

Regis University Student Publications (comprehensive collection)

This academic paper systematically investigates the intricate historical relationship between the United Fruit Company (UFC) and the socio-economic landscape of Costa Rica during the Liberal period from 1870 to 1940. By examining the direct relationship between the UFC's presence and the simultaneous growth of the tourism industry, coastal land development, and the consequential rise of the sex trade, this research elucidates the adverse impacts of foreign monopolies on the privatization of land. The study underscores the enduring repercussions of this phenomenon in contemporary Costa Rican society. Through historical analysis, this thesis argues that the UFC's actions in Costa Rica during …

Community Science And Coyote Stories: Capturing And Communicating Nature's Non-Material Values For Use In Decision-Making, Joshua Wright Morse

Graduate College Dissertations and Theses

The reasons and ways that nature matters underlie every part of environmental decision-making. Yet, there are disparities in how different kinds of benefits from and values about nature are represented in policy and practice. This dissertation explores how decision-makers and community members value nature broadly and also in the context of a specific human-wildlife interaction in Vermont, United States.

In my first chapter, I conduct semi-structured interviews with environmental sector practitioners in Vermont to learn about their awareness of non-material values from nature. I find that practitioners talk readily about both material and non-material ecosystem services as well as multiple …

Environmental Fate Of Sulfur In Sulphur Creek, Valles Caldera, Nm: Implications For Metal Transport And Water Quality, Daniel Lavery

Earth and Planetary Sciences ETDs

The 1.2 Ma Valles Caldera in north-central New Mexico hosts a young igneous volcanic hydrothermal system after the model proposed in Goff and Janik (2000). The Sulphur Springs area within Valles Caldera is an acid-sulfate area typical of this model, discharging acidic waters (pH 1.5-3) formed by oxidation of magmatic H₂S at the surface. We report on samples obtained from springs and streams collected between October 2021 and May 2023 in the Sulphur Creek and Alamo watersheds. Sulphur Creek receives input from Sulphur Springs and exhibits low pH (2-4) and high concentrations of Al (≤110 mg/L), Fe (≤60 …

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 …

The Impact Of Conservation Land On Property Taxes And Municipal Budgets In Maine: A Mixed-Methods Study, Abigail Bennett

Electronic Theses and Dissertations

This study is an interdisciplinary project done in collaboration with the Municipal Budget and Conservation Working group, a group of stakeholders that formed in 2018 to study conservation and town budgets. We use mixed methods to explore the impacts of conservation and municipal budgets in Maine. We use regression analysis on 21 years of panel data to identify causal relationships between conservation and mill rates, controlling for economic and town budget factors. We found statistically significant but small effects on average, with a 1% increase in conserved acres in a town associated with average tax bill increases of $1 or …

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

Open Access Theses & Dissertations

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

The Tidal Prism, Viable Eelgrass Habitat, And The Effects Of Sea Level Rise In Morro Bay, Kaden A. Caliendo

Master's Theses

The tidal prism, or the volume of water exchanged from the sea to an estuary from mean low to mean high tide, influences system hydrodynamics and ecological functioning. Since 1884, the tidal prism in Morro Bay, California has been estimated to be decreasing over time due to sedimentation from upstream practices. What is the current tidal prism in Morro Bay and how will that change with sea level rise? How will eelgrass respond to rising sea levels?

For this study, inexpensive tidal gauges were deployed at four locations in Morro Bay from March to August 2023 to measure spatially varying …

Assessing The Effects Of The Spring Hunting Season Start Date On Wild Turkey Seasonal Productivity And Hunter Behavior, Joseph Quehl

Masters Theses

Many states throughout the Southeast have documented declines in wild turkey (Meleagris gallopavo) harvest and estimates of recruitment in poult-per-hen ratios. Wild turkey populations are driven by seasonal productivity, so the decline in these parameters may indicate a decline in the overall population. One hypothesis as to why we are seeing a reduction in productivity and a potential population decline is that the spring hunting season is disrupting the reproductive cycle by harvesting too many males before they have had the opportunity to breed, or by harvesting dominant males and disrupting the social hierarchy of the flock. Our …

Patterns In Winter Stonefly Distribution Along A River Continuum And Land-Use Gradient In Northwest Arkansas Streams, Zachary Tipton

Graduate Theses and Dissertations

Freshwater ecosystems are facing a crisis with extinction rates of aquatic species exceeding those of their terrestrial counterparts by up to fivefold. This decline is predominantly attributed to evolving land use patterns within watersheds, leading to chemical and physical transformations in freshwater habitats. Northwest Arkansas (NWA) represents one of the fastest-growing regions in the United States, undergoing substantial shifts in land use. Consequently, the status of aquatic life in this region remains uncertain. Addressing this concern, the latest Arkansas Wildlife Action Plan emphasizes the necessity of distribution and population data to guide conservation efforts for Species of Greatest Conservation Need …

Post-Wildfire Effects On A Headwater Stream In The San Bernardino National Forest, Kelley Giron

Electronic Theses, Projects, and Dissertations

Southern California has experienced prolonged drought conditions that have supported frequent wildfires that adversely impact ecosystems, natural resources, and human development. A primary consequence of these events is the impact on water quality and quantity. Of equal concern is evaluating how diverse land use configurations within a watershed can alter the physio-chemical properties of headwater reaches where drought and wildfire conditions are prevalent. To better understand the extent to which wildfires impact water quality and quantity across a headwater watershed, this study investigates wildfire impacts from the 2021 South Fire to Lytle Creek, a headwater stream of the Santa Ana …

Interactions Between Sediment Mechanical Structure And Infaunal Community Structure Following Physical Disturbance, William Cyrus Roger Clemo

<strong> Theses and Dissertations </strong>

Shallow, river-influenced coastal sediments are important for global carbon storage and nutrient cycling and provide a habitat for diverse communities of invertebrates (infauna). Elevated bed shear stress from extreme storms can resuspend, transport, and deposit sediments, disrupting the cohesive structure of muds, and sorting and depositing sand eroded from beaches. These physical disruptions can also resuspend or smother infauna, decreasing abundances and changing community structure. Infaunal activities such as burrowing, tube construction, and feeding can impact sediment structure and stability. However, little is known about how physical disturbance impacts short and long-term sediment habitat suitability and whether disturbance-tolerant infauna influence …

Breaking The Loop: Strategies For Fighting Climate Change On U.S. Farms, Ashley Barry

Honors Capstones

Climate change is an increasingly urgent area of research due to the hardships it causes for lands and communities across the globe. Specifically in regard to the United States (U.S.), climate change has many concerning implications on our agricultural system. Increased weather hazards, decreased crop production, and drought are just a few of the hardships American farmers are facing in their fight to keep their farms alive and feed their communities, despite a rapidly changing climate. This study investigates how farmers can fight and prevent climate change through the use of specific mitigation and adaptation strategies on their farms. Semi- …

A Multi-Regional Assessment Of Eastern Whip-Poor-Will (Antrostomus Vociferus) Occupancy In Managed And Unmanaged Forests Using Autonomous Recording Units, Jeffery T. Larkin

Masters Theses

State and federal agencies spend considerable time and resources to enhance and create habitat for wildlife. Understanding how target and non-target species respond to these efforts can help direct the allocation of limited conservation resources. However, monitoring species response to habitat management comes with several logistical challenges that are exacerbated as the area of geographic focus increases. I used autonomous recording units (ARUs) to mitigate these challenges when assessing Eastern Whip-poor-will (Antrostomus vociferus) response to forest management. I deployed 1,265 ARUs across managed and unmanaged public and private forests from western North Carolina to southern Maine. I then …

Heat Flow In The Southern Margin Of Salar De Atacama: Deep Groundwater Temperature Distributions And The Implications For Subsurface Flow And Land Surface Energy Budgets, Graham Thomas

Masters Theses

Salar de Atacama (SdA) located in Northern Chile is home to one of the planet’s largest salar systems and lithium resources. Managing groundwater resources in salars is not obvious due to the lack of scientific understanding on the connectivity between the freshwater and brine systems. Using heat as a tracer in SdA provides a cost-effective method to further investigate groundwater flow in salars. This study employs 372 temperature-depth profiles from 90 boreholes between 2013-18 to understand the distinct thermal zones and flow between them in SdA. Three thermal zones exist within the southern margin of SdA’s thermal regime, at higher …

Uavs And Deep Neural Networks: An Alternative Approach To Monitoring Waterfowl At The Site Level, Zachary J. Loken

LSU Master's Theses

Understanding how waterfowl respond to habitat restoration and management activities is crucial for evaluating and refining conservation delivery programs. However, site-specific waterfowl monitoring is challenging, especially in heavily forested systems such as the Mississippi Alluvial Valley (MAV)—a primary wintering region for ducks in North America. I hypothesized that using uncrewed aerial vehicles (UAVs) coupled with deep learning-based methods for object detection would provide an efficient and effective means for surveying non-breeding waterfowl on difficult-to-access restored wetland sites. Accordingly, during the winters of 2021 and 2022, I surveyed wetland restoration easements in the MAV using a UAV equipped with a dual …

Assessing Environmental Impact Of The Built Environment By Adopting Life Cycle Design: Using Swanton Pacific Ranch As A Case Study, Hope E. Springer

Master of Science in Environmental Sciences and Management Projects

To combat the carbon emissions contributed to the atmosphere by the built environment, it is imperative that low-embodied-carbon materials choices be prioritized throughout the building design process. To achieve this, this professional project creates an Excel-based, open source, and user-friendly tool for the construction sector to make design decisions that prioritize the sustainability of structures, as one such tool does not currently exist. The use of OpenLCA software and the EcoInvent34 database are utilized to calculate the environmental impact of 25 different building materials, as well as energy and electricity consumption. Swanton Pacific Ranch (SPR) in Santa Cruz County is …

Pumping-Induced Drawdown Of Streams In Proximity To Agricultural Wells, Sara Alina Sternberg

Master of Science in Environmental Sciences and Management Projects

In the context of unprecedented drought and aquifer overdraft in California, understanding surface water and groundwater connectivity have become increasingly important. While there is a clear understanding of how wells induce drawdown in aquifers (Theis, 1935; Hantush, 1965), secondary effects on local streams have not fully been considered. Current mathematical models targeting aquifer drawdown do not address stream drawdown response in aquifer-stream systems with strong connectivity; instead, they assume the stream to be a constant head boundary. In the drought-stricken and summer-dry climate of California, streams often run dry for months out of the year, which is currently not reflected …

Integrating Environmental Dna, Traditional Fisheries Techniques, And Species Distribution Modeling To Assess Bridle Shiner Status In Maine, Lara S. Katz

Electronic Theses and Dissertations

The bridle shiner (Notropis bifrenatus) is a small minnow species native to the eastern United States and southeastern Canada. The species is declining dramatically throughout most of its native range and has legal protection or concern status in thirteen states and two Canadian provinces. In Maine, the bridle shiner is listed as a Species of Special Concern and considered a Species of Greatest Conservation Need, partially because we lack a basic understanding of their status and distribution within the state. Bridle shiners have historically been found in southern and western Maine in densely vegetated, shallow habitats along the …

A Four-Pronged Approach To Addressing A Wild Pig Invasion In A Bottomland And Upland Forested Landscape, Tyler Scott Evans

Theses and Dissertations

Among exotic species that are capable of invading, establishing, and reaching pest status, few pose the range of impacts to biotic (e.g., competition with native species, predation, herbivory, introduction of other exotics) and abiotic (e.g., soil, hydrology) ecosystem components that can be attributed to the wild pig (Sus scrofa). Despite the presence of wild pigs throughout the southeastern United States for centuries, new invasions continue to occur in previously uninhabited and often under-investigated landscapes, including bottomland and upland forests. The recent invasion of the Sam D. Hamilton Noxubee National Wildlife Refuge (hereafter, NNWR) in east-central Mississippi represents an …

Optimizing Edge-Of-Field Water Quality Monitoring Methods To Determine The Effects Of Best Management Practices On Nutrient And Sediment Runoff, Mark Hill

Theses and Dissertations

This study investigates the impact on water quality of combined agricultural best management practices cover crop and minimum tillage, alongside an examination of techniques used to collect those samples. Edge-of-field (EOF) water quality samples were collected from 11 working farms during a two-year paired field experiment. Results showed significant reductions in nutrient concentrations, increased discharge, and mixed findings regarding nutrient mass transport post-treatment. A suite of EOF collection techniques were compared using in-situ automated water sampling systems sampling the same runoff events. Sampling protocols influenced nutrient concentrations in composite samples, but unexpected variance in velocity sensors affected measured discharge, making …

Investigating The Role Of Plant Traits And Interactions In Emergent Wetland Nutrient Removal, Andrew Ryan Sample

Theses and Dissertations

Increasing wetland restoration in the Lower Mississippi Alluvial Valley has been identified as a method to reduce nutrient loading in the Gulf of Mexico. Wetlands have historically been used to treat water through processes facilitated by wetland plants, and relatively few species and plant traits have been identified as important in carrying out these processes. This study focuses on some of those species and traits and aims to identify species differences and plant traits that may be important for wetland nutrient mitigation. Chapter I provides background information on nutrient pollution, wetland biogeochemical mechanisms for nutrient sequestration, and the focal species …

Can Gulf Ribbed Mussels Enhance Coastal Restoration Projects In A Future With Climate Change?, Skylar Liner

LSU Master's Theses

Living shorelines present one restoration approach using biotic elements (via ecosystem engineers) to stabilize shorelines and increase valuable habitat. Gulf ribbed mussels (Geukensia granosissima) are important ecosystem engineers within brackish and salt marshes in the northern Gulf of Mexico, and can increase nutrient availability, enhance marsh vegetation production, and potentially improve shoreline stability. It is unknown whether mussels will maintain these functions as future climate change predicts increases in temperature and water level, which may exceed the mussel’s tolerance. A field survey conducted during the summer of 2022 identified the daily maximum temperature at the marsh surface, where mussels naturally …

Geospatial Wildfire Risk Prediction Using Deep Learning, Abner Alberto Benavides

Electronic Theses, Projects, and Dissertations

This report introduces a thorough analysis of wildfire prediction using satellite imagery by applying deep learning techniques. To find wildfire-prone geographical data, we use U-Net, a convolutional neural network known for its effectiveness in biomedical image segmentation. The input to the model is the Sentinel-2 multispectral images to supply a complete view of the terrain features.

We evaluated the wildfire risk prediction model’s performance using several metrics. The model showed high accuracy, with a weighted average F1 score of 0.91 and an AUC-ROC score of 0.972. These results suggest that the model is exceptionally good at predicting the location of …

Annotation Of Non-Model Species’ Genomes, Taiya Jarva

Master's Theses

The innovations in high throughput sequencing technologies in recent decades has allowed unprecedented examination and characterization of the genetic make-up of both model and non-model species, which has led to a surge in the use of genomics in fields which were previously considered unfeasible. These advances have greatly expanded the realm of possibilities in the fields of ecology and conservation. It is now possible to the identification of large cohorts of genetic markers, including single nucleotide polymorphisms (SNPs) and larger structural variants, as well as signatures of selection and local adaptation. Markers can be used to identify species, define population …

Influence Of Woody Vegetation Composition And Structure On Fuels And Prescribed Fire In Mountain Longleaf Restoration, Collin J. Anderson

Master of Science in Integrative Biology Theses

Longleaf pine (LLP) ecosystems have experienced a widespread ecological state shift largely due to fire exclusion which has allowed mesophytes, i.e., shade-tolerant, often fire-sensitive species to encroach, reducing flammability and biodiversity through a process known as “mesophication.” Although prescribed fire is commonly used to reverse mesophication, fire behavior, and thus prescribed fire utility for this purpose, is poorly characterized in mixed pine-hardwood stands with mesophyte encroachment. This study aimed to identify mechanisms by which tree composition, structure, and fuels contribute to fire behavior, focusing on the understudied mountain longleaf pine (MLLP) ecoregion in northwest Georgia. I hypothesized that woody vegetation …