Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 2491 - 2520 of 17792

Full-Text Articles in Entire DC Network

Investigating The Thermal Stratification Patterns Of A Shallow Polymictic Boreal Shield Lake And The Effectiveness Of Models In Predicting Shallow Lake Thermal Profiles, Matthew Roberts Jan 2025

Investigating The Thermal Stratification Patterns Of A Shallow Polymictic Boreal Shield Lake And The Effectiveness Of Models In Predicting Shallow Lake Thermal Profiles, Matthew Roberts

Theses and Dissertations (Comprehensive)

Thermal stratification is a core process of lakes which plays a critical role in shaping the ecological dynamics of lakes, influencing major processes like nutrient cycling and oxygen availability. For shallow polymictic lakes, thermal stratification patterns present some unique differences due to the complex and variable nature of these lakes. In this thesis, I examined thermal stratification in a shallow polymictic lake in northwestern Ontario during the ice-free season of 2019 to investigate the frequency, duration, and driving factors of thermal stratification. The lake underwent 146 separate stratification events, with a median duration of 2 hours per event, with a …


Multi-Source Remote Sensing–Based Soil Moisture Prediction Using Machine Learning, Niraj Neupane Jan 2025

Multi-Source Remote Sensing–Based Soil Moisture Prediction Using Machine Learning, Niraj Neupane

Electronic Theses and Dissertations

Soil moisture (SM) plays a central role in climatic and environmental processes, influencing shear strength of soil, agricultural productivity, land–atmosphere interactions, and hydrologic functioning. However, accurately estimating SM across diverse climatic regions remains challenging due to spatial heterogeneity, limited in situ measurements, and inconsistencies in sensor resolution. Machine learning (ML) and remote sensing offer promising avenues for improving SM prediction, yet many existing approaches struggle with generalization across climatic gradients and often fail to capture temporal variability. This study integrates multi-source satellite and climate datasets, including SMAP L4_SM, MODIS land surface temperature, Daymet meteorological variables, and in situ observations from …


Enhancing Alfalfa Persistence In Rangelands: Evaluating Morphological Traits Of Medicago Sativa Subsp. Falcata Germplasm, Abdulallah Mohammed Alomair Jan 2025

Enhancing Alfalfa Persistence In Rangelands: Evaluating Morphological Traits Of Medicago Sativa Subsp. Falcata Germplasm, Abdulallah Mohammed Alomair

Electronic Theses and Dissertations

Rangelands cover nearly half of the Earth’s surface, representing about 54% (79 million km2), and occur in different types and climates worldwide. Alfalfa (Medicago sativa L.) is a major component in rangelands and covers about (320 thousand km2), representing about 0.4% of total global rangeland area. As a critical perennial legume crop, alfalfa can improve soil health by fixing approximately 336 kg/ha/year of nitrogen and sequestering up to 614 kg/ha/year of carbon, while enhancing livestock production due to its high content level of vitamins, magnesium, minerals, fiber, and protein. However, environmental stresses such as drought, freezing, and grazing limit alfalfa …


Bridging Prairie Restoration And Regenerative Agriculture With Compost Tea / The Rocket Incident: Post-Fire Soil Microbe Recovery On The Eastern Washington University Restoration Site, April Hersey Jan 2025

Bridging Prairie Restoration And Regenerative Agriculture With Compost Tea / The Rocket Incident: Post-Fire Soil Microbe Recovery On The Eastern Washington University Restoration Site, April Hersey

EWU Masters Thesis Collection

Inland Pacific Northwest prairie is an endangered ecosystem that has been reduced by conversion to agriculture. There is growing interest in the role of soil microorganisms in prairie ecosystems, which may be crucial for restoration of the plant community through interspecies interactions within the rhizosphere. One method for improving soil microorganism community composition is compost tea: enriched liquid compost extract. Compost tea is used in regenerative agriculture to improve crop yields and protect against pathogens. While research has supported compost tea application in regenerative agriculture, it has not been widely studied in the context of ecosystem restoration. After beginning a …


Cropsync: Ai-Powered Sustainable Crop Management, Ziad Doughan, Ibrahim Mneimneh, Zouheir Nakouzi, Noor Al Khaib, Samer Damaj, Jamal Chaaban, Hamza Mrad, Sari Itani Dec 2024

Cropsync: Ai-Powered Sustainable Crop Management, Ziad Doughan, Ibrahim Mneimneh, Zouheir Nakouzi, Noor Al Khaib, Samer Damaj, Jamal Chaaban, Hamza Mrad, Sari Itani

BAU Journal - Science and Technology

CropSync is a smart agriculture system that uses AI and IoT technologies to enable sustain- able crop management and precision farming. The system aims to address the challenges faced by the agriculture sector, such as increasing food production to meet global population demands while minimizing environmental impact. CropSync integrates sensors, cameras, and cloud-based analytics to provide farmers with real-time insights and recommendations for optimizing crop cul- tivation. The system upholds engineering professional and ethical standards, considering broader social, environmental, and economic implications. From a social perspective, CropSync improves food security and enhances farmers’ livelihoods through increased productivity and efficient re- …


Coal Gasification Through Microbial Degradation In A Low-Pressure Co2 And H2 Environment: An Experimental Study, Jian Kuo, Fu Xuehai, Liu Mingjie, Liu Jian, Li Jin, Ru Zhongliang, Ji Xiaofeng, Wang Qiang Dec 2024

Coal Gasification Through Microbial Degradation In A Low-Pressure Co2 And H2 Environment: An Experimental Study, Jian Kuo, Fu Xuehai, Liu Mingjie, Liu Jian, Li Jin, Ru Zhongliang, Ji Xiaofeng, Wang Qiang

Coal Geology & Exploration

Objective and Methods This study aims to investigate the characteristics of CO2 biomethanation and coal gasification through microbial degradation in a low-pressure environment. With low-rank bituminous coals (Rmax = 0.67%) as fermentable substrates, this study conducted a 96-day gas production experiment through microbial fermentation in a low-pressure CO2 and H2 environment. Using techniques including gas chromatography, 16S rRNA gene sequencing, and low-temperature liquid nitrogen adsorption, this study delved into the intrinsic variation patterns of biogenic gas production, microbial communities, and coal structures. Results and Conclusions The results indicate that compared to conventional fermentation, the injection …


Biomimetic Technologies For Drill Rods: Advances In Research And Development Trends, Wang Chuanliu, Ju Pei Dec 2024

Biomimetic Technologies For Drill Rods: Advances In Research And Development Trends, Wang Chuanliu, Ju Pei

Coal Geology & Exploration

Significance Drill rods are recognized as core tools in drilling engineering, and their performance exerts a significant influence on drilling efficiency and safety. Over recent years, applying biomimetic technologies to drill rod design has gradually emerged as a hot research topic. By imitating the remarkable structures, morphologies, and material properties of living organisms in nature, biomimetic technologies provide entirely new philosophies and approaches for the innovative design of drill rods. Advances This study summarizes the advances in research on biomimetic technologies for drill rods in terms of the biomimetic design of structures, morphologies, and materials. Regarding the biomimetic design of …


Microbial Diversity And Biogeochemical Interactions In The Seismically Active And Co2-Rich Eger Rift Ecosystem, Daniel Lipus, Zeyu Jia, Megan Sondermann, Robert Bussert, Alexander Bartholomäus, Sizhong Yang, Dirk Wagner, Jens Kallmeyer Dec 2024

Microbial Diversity And Biogeochemical Interactions In The Seismically Active And Co2-Rich Eger Rift Ecosystem, Daniel Lipus, Zeyu Jia, Megan Sondermann, Robert Bussert, Alexander Bartholomäus, Sizhong Yang, Dirk Wagner, Jens Kallmeyer

College of Life Sciences Faculty Papers

The Eger Rift subsurface is characterized by frequent seismic activity and consistently high CO2 concentrations, making it a unique deep biosphere ecosystem and a suitable site to study the interactions between volcanism, tectonics, and microbiological activity. Pulses of geogenic H2 during earthquakes may provide substrates for methanogenic and chemolithoautotrophic processes, but very little is currently known about the role of subsurface microorganisms and their cellular processes in this type of environment. To assess the impact of geologic activity on microbial life, we analyzed the geological, geochemical, and microbiological composition of rock and sediment samples from a 238 m deep drill …


Highway Crossing Rates Of Wild Felids Before, During, And After Wildlife Crossing Structure Installation, Sarah E. Lehnen, Mitch Sternberg, Hilary M. Swarts, John H. Young Jr., Victoria Hanley, Richard J. Kline Dec 2024

Highway Crossing Rates Of Wild Felids Before, During, And After Wildlife Crossing Structure Installation, Sarah E. Lehnen, Mitch Sternberg, Hilary M. Swarts, John H. Young Jr., Victoria Hanley, Richard J. Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

In an environment increasingly dominated by roads, wildlife crossing structures (WCS) have been installed to decrease wildlife mortality and improve habitat linkages. In South Texas, vehicle collisions have been a major mortality source for the endangered ocelot ( Leopardus pardalis ). To mitigate threats to this species, eight WCS, along with associated fencing, were strategically placed along Farm‐to‐Market Road 106 (FM106), which passes through ocelot habitat. We assessed the rate of on‐roadway crossings and WCS use by GPS‐collared animals before, during, and after WCS installation using camera traps to verify WCS use. Because of the rarity of ocelots in this …


Two Decades Of Climate Measurements Reveal El Niño's Role In Andean Elevation-Dependent Warming, Luke Davies Dec 2024

Two Decades Of Climate Measurements Reveal El Niño's Role In Andean Elevation-Dependent Warming, Luke Davies

Honors Program Theses and Projects

Driven by climate change, elevation-dependent warming (EDW) has become a critical issue in the Cordillera Blanca of Peru. This study focuses on gathering evidence of EDW and determining the relationship between El Niño Southern Oscillation (ENSO) events and micrometeorological forcing in two proglacial valleys. A climate monitoring network was maintained through a 20-year collaboration between Bridgewater State University (BSU), Universidad Nacional Santiago Antúnez de Mayolo (UNASAM), and the Autoridad Nacional de Agua (ANA). Fieldwork in June 2023 and June 2024 included repairing weather stations, installing new Lascar sensors, and downloading data loggers to sustain and improve the climate record. Data …


The Role Of Nutrient Solutions On Phosphate-Solubilizing Bacteria Population, Phosphorus Availability, Phosphorus Uptake, Growth And Yield Of Red Chili (Capsicum Annuum L.), Betty Natalie Fitriatin, Raden Faqih Hilmiy Ghifari, Emma Trinurani Sofyan, Fitri Widiantini, Hanif Fakhrurroja, Tualar Simarmata Dec 2024

The Role Of Nutrient Solutions On Phosphate-Solubilizing Bacteria Population, Phosphorus Availability, Phosphorus Uptake, Growth And Yield Of Red Chili (Capsicum Annuum L.), Betty Natalie Fitriatin, Raden Faqih Hilmiy Ghifari, Emma Trinurani Sofyan, Fitri Widiantini, Hanif Fakhrurroja, Tualar Simarmata

Jurnal Kultivasi

Red chili consumption in Indonesia has increased every year. However, with large chili production to meet large consumption, land conversion for various purposes has reduced the harvested area. The efforts to increase the harvested area of chili using Inceptisols soil by providing nutrient solutions to overcome the infertility of the soil using its nutrients. This experiment aims to determine the effect of nutrient solution application on the population of phosphate-solubilizing bacteria, phosphorus availability, phosphorus uptake, growth, and yield of Red Chili (Capsicum annuum L.) in Inceptisols. The experiment was conducted from August 2023 to February 2024 at Ciparanje Experimental Field, …


Geomorphic Evolution Of St. Augustine Inlet, St. Johns County, Florida, Kristen Becker Dec 2024

Geomorphic Evolution Of St. Augustine Inlet, St. Johns County, Florida, Kristen Becker

Theses and Dissertations

Tidal inlets interrupt longshore sediment transport, influencing adjacent beach morphology and allowing the exchange of water and sediment between the open oceans and protected back barrier bay. Inlets evolve through a combination of natural processes and are highly dynamic zones where sediment exchanges cause shifting shoreline positions nearby and create new morphological features. Barrier islands/beaches that are close in proximity to inlets evolve and are an important natural feature that dissipates wave energy and protects inland areas. Both natural and anthropogenic processes that affect barrier islands will be investigated during this study, including storm activity, waves, wind, water level, and …


Are There Neurological Impacts Of Exposure To A Burned Wildfire Site As It Recovers?, Rubye Strickland Dec 2024

Are There Neurological Impacts Of Exposure To A Burned Wildfire Site As It Recovers?, Rubye Strickland

Undergraduate Honors Theses

Wildfires are increasing with climate change, making the human health implications of exposure to burned soils an essential area of research. Metals associated with fire-impacted soils can be inhaled or accidentally ingested by surrounding communities, causing health risks. Several studies have evaluated the health impact of wildfires, but few have done so from a neurological perspective. This study explores metal changes in burned soils over time as a site naturally recovers from wildfire and how these changes may impact human neurological health. Soil samples were collected from the burned area 0, 3, 6, 9, and 12 months after the fire. …


Algal Community Investigations: Present Day To Year-2100 For Mississippi Lakes And The Western Mississippi Sound, Emma Madison Tucker Dec 2024

Algal Community Investigations: Present Day To Year-2100 For Mississippi Lakes And The Western Mississippi Sound, Emma Madison Tucker

Theses and Dissertations

Algae play a key role in the aquatic environment as primary producers; however, they can form harmful algal blooms that are detrimental to the aquatic environment, people, and even the economy. It is generally believed that climate change will influence future algal blooms. The first study estimated algae community in three freshwater locations in Mississippi, Desoto Lake, White’s Creek Lake, and Columbus Lake, and one saline location, Western Mississippi Sound, using modern and new tools of the autonomous surface vessel, FlowCam, and EcoTaxa. From those results and leading into the second study was the application of four climate scenarios on …


Climate And Gypsum Parent Material Shape Biocrust Communities And Moss Ecology In The Chihuahuan And Mojave Deserts, Nicole Pietrasiak, Katelyn G. Gobbie, Brian Jusko, Rebecca E. Drenovsky Dec 2024

Climate And Gypsum Parent Material Shape Biocrust Communities And Moss Ecology In The Chihuahuan And Mojave Deserts, Nicole Pietrasiak, Katelyn G. Gobbie, Brian Jusko, Rebecca E. Drenovsky

Life Sciences Faculty Research

Biological soil crust communities (biocrusts) establishing on gypsum soils have been well-documented for their prolific appearance and rich diversity of lichens and bryophytes. However, studies characterizing gypsum biocrusts have occurred primarily outside of the U.S., most of which lack comparisons to other soil types. We conducted intensive field surveys to evaluate the ground cover and frequency of biocrust functional groups and moss species on gypsum and non-gypsum soils in the U.S. regions with the most extensive gypsum outcrops, the northern Chihuahuan and eastern Mojave Deserts. Study sites were stratified by geomorphology and paired, so that every gypsum site was matched …


Growth And Yield Of Bok Choy (Brassica Rapa L.) Plants In Post-Rock Excavation Soils Provided With Phosphate-Solubilizing Bacteria And Manure, Cecep Hidayat, Yati Setiati Rachmawati, Dhea Rizqi Utami, Sofiya Hasani, Anna Aina Roosda, Windhy Chandria Dec 2024

Growth And Yield Of Bok Choy (Brassica Rapa L.) Plants In Post-Rock Excavation Soils Provided With Phosphate-Solubilizing Bacteria And Manure, Cecep Hidayat, Yati Setiati Rachmawati, Dhea Rizqi Utami, Sofiya Hasani, Anna Aina Roosda, Windhy Chandria

Jurnal Kultivasi

Elevated sand and gravel mining to meet market needs causes negative impacts on the environment, soil, and biodiversity. The government issued a regulation that requires revegetation as reclamation of mineral and coal mining. The conversion needs to overcome the physical and chemical characteristics of post-rock excavation soil that can be utilized by economic value plants such as bok choy. This experiment aimed to determine the growth and yield of bok choy on post-rock excavation soil by providing phosphate solubilizing bacteria (PSB) and various manure types. The study was conducted in Margasari Village, Buah Batu District, Bandung at an altitude of …


Bioremediation Of Pb And Cd Contaminated Soil By Mycorrhiza And Biochar Treatment And Its Effect On Growth And Yield Of Shallot, Okti Herliana, Wilis Cahyani, Yugi Rahayu Ahadiyat Dec 2024

Bioremediation Of Pb And Cd Contaminated Soil By Mycorrhiza And Biochar Treatment And Its Effect On Growth And Yield Of Shallot, Okti Herliana, Wilis Cahyani, Yugi Rahayu Ahadiyat

Jurnal Kultivasi

The contamination of shallots in the food chain by heavy metals such as lead (Pb) and cadmium (Cd) is caused by chemical fertilizers and pesticides. The study aimed to determine the growth and yields of shallot cultivated on soil contaminated with Pb and Cd using mycorrhiza and biochar. The study was conducted in the screen house at Jenderal Soedirman University, Faculty of Agriculture, from April to September 2020, and it was carried out using a factorial Randomized Completely Block Design that involved three replications and two factors. The first factor of mycorrhiza dosage comprised 0, 1, and 2 g/pot, and …


Bioremediation Of Pb And Cd Contaminated Soil By Mycorrhiza And Biochar Treatment And Its Effect On Growth And Yield Of Shallot, Okti Herliana, Wilis Cahyani, Yugi Rahayu Ahadiyat Dec 2024

Bioremediation Of Pb And Cd Contaminated Soil By Mycorrhiza And Biochar Treatment And Its Effect On Growth And Yield Of Shallot, Okti Herliana, Wilis Cahyani, Yugi Rahayu Ahadiyat

Jurnal Kultivasi

The contamination of shallots in the food chain by heavy metals such as lead (Pb) and cadmium (Cd) is caused by chemical fertilizers and pesticides. The study aimed to determine the growth and yields of shallot cultivated on soil contaminated with Pb and Cd using mycorrhiza and biochar. The study was conducted in the screen house at Jenderal Soedirman University, Faculty of Agriculture, from April to September 2020, and it was carried out using a factorial Randomized Completely Block Design that involved three replications and two factors. The first factor of mycorrhiza dosage comprised 0, 1, and 2 g/pot, and …


Current Status And The Significance Of Local Wisdom Biofertilizer In Enhancing Soil Health And Crop Productivity For Sustainable Agriculture: A Systematic Literature Review, Irwandhi, Fiqriah Hanum Khumairah, Emma Trinurani Sofyan, Nadia Nuraniya Kamaluddin, Anne Nurbaity, Diyan Herdiyantoro, Tualar Simarmata Dec 2024

Current Status And The Significance Of Local Wisdom Biofertilizer In Enhancing Soil Health And Crop Productivity For Sustainable Agriculture: A Systematic Literature Review, Irwandhi, Fiqriah Hanum Khumairah, Emma Trinurani Sofyan, Nadia Nuraniya Kamaluddin, Anne Nurbaity, Diyan Herdiyantoro, Tualar Simarmata

Jurnal Kultivasi

Soil fertility is recognized as a crucial factor in supporting plant growth and productivity. The utilization of biofertilizers as environmentally friendly fertilizers is aimed at enhancing soil fertility and plant productivity. This study aims to explore the potential of local material for developing local wisdom biofertilizers (LWB) for achieving sustainable agriculture. A systematic literature review was conducted using bibliometric analysis, Preferred Reporting Items for Systematic Reviews, and Meta-Analyses (PRISMA) method, employing the Scopus search engine with the keywords "local AND wisdom AND biofertilizer" OR "biofertilizer" OR "local AND microorganism" OR "soil AND health OR crop AND productivity OR sustainable agriculture". …


Net Evaporation-Induced Mangrove Area Loss Across Low-Lying Caribbean Islands, Isamar M. Cortés, Jorge Lorenzo-Trueba, Andre S. Rovai, Robert R. Twilley, Mark Chopping, Temilola Fatoyinbo Dec 2024

Net Evaporation-Induced Mangrove Area Loss Across Low-Lying Caribbean Islands, Isamar M. Cortés, Jorge Lorenzo-Trueba, Andre S. Rovai, Robert R. Twilley, Mark Chopping, Temilola Fatoyinbo

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Although mangroves provide many beneficial ecosystem services, such as blue carbon storage and coastal protection, they are currently under threat due to changes in climate conditions, such as prolonged drought exposure. Under drought conditions, evaporation exceeds precipitation and high soil salinities can lead to stunted growth and die-back. To quantify this interplay, we developed a database for low-lying and uninhabited mangrove islands in the Caribbean under various evaporation and precipitation regimes. We extracted physical and biological information from each island using remote sensing techniques and coupled it with a process-based model. We used this database to develop a model that …


Heavy Metals In Rural Soils: A Case Study In Jennings County, Indiana, Madeline Hill Dec 2024

Heavy Metals In Rural Soils: A Case Study In Jennings County, Indiana, Madeline Hill

All-Inclusive List of Electronic Theses and Dissertations

Heavy metals, such as lead and mercury, can be toxic if exposure levels are too high. People are often concerned about lead exposure from water or paint, but soil is another potential exposure avenue for many metals. While some heavy metals, including mercury and lead, are found in emissions from coal-burning power plants and from incinerators, many metals accumulate in soils from past uses (ex. lead paint, leaded gasoline, chemical spills, industrial emissions, and natural occurrences). It is important to have soil tested to check metal concentrations because consumption or inhalation of these metals can lead to permanent damage and …


Creating Place-Based Introductory Geoscience Field Trip Curricula For Indigenous Students, Kitri Spencer Dec 2024

Creating Place-Based Introductory Geoscience Field Trip Curricula For Indigenous Students, Kitri Spencer

All Graduate Reports and Creative Projects, Fall 2023 to Present

This project seeks to produce and evaluate a place-based geoscience field trip curriculum along the San Juan River designed for Indigenous students. The Geoscience on the San Juan River field trip uses a “place-based” approach to weave scientific concepts with the cultural knowledge and lived experiences of the students. Learning activities were designed to accommodate a wide range of learning preferences and accessibility needs with the hope of increasing Indigenous enrollment in the geosciences. The lesson plan was tested on June 4th, 2022 during a guided rafting excursion on the San Juan River for students participating in the …


A Review Of The Philosophy Of Flood Risk Communication And Education: New Insights Informed By Critical Complexity, Timothy Lutz Dec 2024

A Review Of The Philosophy Of Flood Risk Communication And Education: New Insights Informed By Critical Complexity, Timothy Lutz

Earth & Space Sciences Faculty Publications

The approach to flooding in the U.S. is strongly influenced by research and practices that place the responsibility for managing risk on scientific and technical experts. But there is a recognition that the public generally needs to be more engaged and responsible. There is currently a disconnect between the objective knowledge of experts and the more subjective ways in which people experience floods and flood risk. To bridge this gap, I start with a review of the philosophy that informs government policies and the societal worldview. While societal leaders have maintained a mechanistic vision of a world that is ultimately …


Sedimentary Characteristics Of Flood Deposits In Coastal And Fluvial Environments: Examples From Washover Fans (North Carolina, Usa) And Floodplain Deposits (Mississippi, Usa), Shara Gremillion Dec 2024

Sedimentary Characteristics Of Flood Deposits In Coastal And Fluvial Environments: Examples From Washover Fans (North Carolina, Usa) And Floodplain Deposits (Mississippi, Usa), Shara Gremillion

Dissertations

Extreme flooding from severe and prolonged meteorological events and / or overbanking rivers are some of the most deadly and expensive disasters globally, impacting millions of lives, the environment, and property. People living in vulnerable areas, such as near coasts and rivers, are the first to be impacted with effects of these flood hazards. Scientific studies and their results can aid communities and officials in planning and preparing for those flood impacts. In this three-part study, flood impacts from coastal storms in North Carolina, and flooding along the Mississippi River (MSR) in the state of Mississippi, USA are assessed from …


Spatial-Textural Study Of Siliciclastics In A Navajo Sandstone Carbonate Lens, Christopher L. Rupe Dec 2024

Spatial-Textural Study Of Siliciclastics In A Navajo Sandstone Carbonate Lens, Christopher L. Rupe

Loma Linda University Electronic Theses, Dissertations & Projects

Flat-lying carbonate deposits in the Lower Jurassic Navajo Sandstone have long been interpreted as interdune lacustrine deposits. This dissertation critically assesses such inference through the study of an exceptionally well-preserved carbonate deposit in the Trough Canyon area, northwest of Moab, Utah. Thickness measurements along multiple cross-sectional exposures were used to construct an isopach map, approximating the original size and lenticular geometry of the deposit. Dip directions were recorded from foreset strata in cross-bed sets stratigraphically overlying the deposit to infer the approximately coeval direction of siliciclastic transport across the carbonate basin. These data sets yielded a contextual framework for studying …


Microplastic Degradation Compared Among Dated Salton Sea Strandlines, Maria Alejandra Roman Medrano Dec 2024

Microplastic Degradation Compared Among Dated Salton Sea Strandlines, Maria Alejandra Roman Medrano

Loma Linda University Electronic Theses, Dissertations & Projects

This thesis investigates the environmental degradation of plastic materials, with a focus on polyethylene terephthalate (PET), through a multi-phase study conducted at the Salton Sea, a closed-basin lake in a semi-arid region of California. The research addresses three core objectives: (1) developing a microplastic (MP) extraction method tailored for clay-rich sediments, (2) characterizing surface degradation of various plastic types, including PET, BoPET, HDPE, LDPE, and EPS, using advanced microscopy and spectroscopy, and (3) examining the long-term weathering of PET through samples collected from dated lake strandlines.

The extraction protocol successfully isolates MPs without oxidation, using ZnCl₂ and extended soaking to …


Performance Of Acoustic Telemetry And Space Use Of Pallid Sturgeon In The Lower Platte River, Nebraska, Christopher F. Pullano Dec 2024

Performance Of Acoustic Telemetry And Space Use Of Pallid Sturgeon In The Lower Platte River, Nebraska, Christopher F. Pullano

School of Natural Resources: Dissertations, Theses, and Student Research

Pallid Sturgeon (Scaphirhynchus albus) are centenarian, potamodromous, rheophiles that historically occupied the Missouri River and Mississippi River basins. Listed on the U.S. Endangered Species Act in 1990, population declines are attributed to habitat fragmentation and degradation, as well as overharvest, and hybridization. A knowledge gap exists regarding the extent to which tributaries facilitate key life stages for Pallid Sturgeon. This study evaluated the capacity of acoustic telemetry to monitor the movements of Pallid Sturgeon in a shallow, braided tributary to the Missouri River. The specific objectives were to (1) evaluate the environmental variables influencing the performance of acoustic …


Occupancy Of Fish Species Of Greatest Conservation Need And Temporal Patterns Of Assemblage Occurrence In Sandhills Ecoregion, Nebraska Streams, Braxton M. Newkirk Dec 2024

Occupancy Of Fish Species Of Greatest Conservation Need And Temporal Patterns Of Assemblage Occurrence In Sandhills Ecoregion, Nebraska Streams, Braxton M. Newkirk

School of Natural Resources: Dissertations, Theses, and Student Research

Fish species’ occurrence is influenced by environmental conditions across multiple spatial and temporal scales. Alteration to stream systems has the potential to affect occurrence patterns of fish species. Stream systems of the North American Great Plains face threats originating from climate change and anthropogenic activities resulting in negative implications for many fish species. The Sandhills Ecoregion, Nebraska is considered one of the largest intact grasslands in North America, and thus may experience fewer threats than surrounding areas. Stream systems of the Sandhills Ecoregion are home to 12 fish species of greatest conservation need (SGCN). Little context exists regarding the environmental …


Implementing Organic Fertilization Practices To Improve Aloe Vera Growth And Soil Health In The Lower Rio Grande Valley, Isaiah Edward Jaramillo Dec 2024

Implementing Organic Fertilization Practices To Improve Aloe Vera Growth And Soil Health In The Lower Rio Grande Valley, Isaiah Edward Jaramillo

Theses and Dissertations

Aloe vera (L.) (Aloe) Burm. f., is valued for its applications across the cosmetic, medicinal, and food industries due to its leaf gel. In the aloe industry, the extraction of gel from leaves generates significant quantities of organic waste, which presents an opportunity to repurpose this material as an amendment in aloe cultivation. While Aloe is renowned for its resilience, understanding the feasibility of using these organic shavings as a soil fertility amendment in aloe production is critical. This research aims to identify sustainable fertilization methods for Aloe that can maintain and/or improve crop yield while enhancing soil health. This …


A Nursery Study Of The Interplay Between Soil Texture, Rooting Space, And Nurse Plants On Seedling Growth And Root Development In Woody Species Of Tamaulipan Thornscrub, Lance I. Santos Dec 2024

A Nursery Study Of The Interplay Between Soil Texture, Rooting Space, And Nurse Plants On Seedling Growth And Root Development In Woody Species Of Tamaulipan Thornscrub, Lance I. Santos

Theses and Dissertations

Reforestation attempts in semi-arid regions are plagued with seedling mortality. Blanket greenhouse practices may not be optimal, in addition, commensalism interactions between nurse plants are considered. To better understand the effects of soil texture and nurse plant interactions on growth and drought tolerance, two experiments were developed. For soil texture, Border palo verde seedlings were grown in different-sized plant bands with three soil types. To observe the effects of nurse plants, an experiment using guayacan, was developed using Texas Ebony, as a leguminous nurse plant. Plants were also exposed to a drought experiment. The results suggest that some soil textures …