Metagenomic Investigation Of Microbial Dark Carbon Fixation, Viral Interactions, And Horizonal Gene Transfer Within A Convergent Margin Subsurface Ecosystem, 2023 University of Tennessee, Knoxville
Metagenomic Investigation Of Microbial Dark Carbon Fixation, Viral Interactions, And Horizonal Gene Transfer Within A Convergent Margin Subsurface Ecosystem, Timothy Joseph Rogers
Doctoral Dissertations
Convergent margins are geological regions where two or more tectonic plates collide, and the denser “subducting slab” is pushed beneath the less dense overriding plate. As the slab descends, it devolatilizes under higher temperatures and pressures, allowing dissolved inorganic carbon (DIC) and redox active volatile rich fluids to cycle between the upper crust and Earth’s mantle. These fluids migrate through cracks and fissures in the upper mantle and crust, fueling chemolithoautotrophy-based microbial ecosystems in the subsurface before they are expelled on the surface in the form of hydrothermal seeps and springs. Chemolithoautotrophic ecosystems, such as those in the Costa Rican …
Nutrient Dynamics Of Freshwater Estuarine Sediments Disturbed By Dredging, 2023 University of Wisconsin-Milwaukee
Nutrient Dynamics Of Freshwater Estuarine Sediments Disturbed By Dredging, Ryan Allan John Roekle
Theses and Dissertations
This study examined the nutrient environment of sediments in the Milwaukee River estuary and the dynamics of those nutrients during simulated disturbance experiments within the context of large-scale dredging remediation. Surface sediments were collected from throughout the Milwaukee estuary (including river, harbor, and nearshore stations) by PONAR, centrifuged to separate porewater (interstitial water) from solid material, and filtered to further isolate and stabilize dissolved material. Porewaters were analyzed for dissolved nutrients including ammoniacal nitrogen (AN), nitrate, nitrite, and soluble reactive phosphorus (SRP). Surface sediment porewaters within the estuary were often highly enriched in AN and SRP, which were often 10-2000x …
High-Energy Storm Events And Their Impacts On Carbon Storage In Tidal Wetlands Of South Carolina, 2023 Clemson University
High-Energy Storm Events And Their Impacts On Carbon Storage In Tidal Wetlands Of South Carolina, Gavin Gleasman
All Dissertations
Atmospheric carbon dioxide (CO2) concentrations have been increasing at an accelerating rate for the past two centuries, profoundly impacting global climate change. Atmospheric CO2 concentrations are influenced by the global carbon cycle through physical and biogeochemical pathways. Tidal wetland environments play a vital role in the global carbon cycle by offsetting atmospheric CO2 concentrations through their natural physiochemical processes of high autotrophic productivity, allochthonous organic matter deposition, anoxic soils, and continuous accretion which promotes carbon sequestration with long-term storage at the land-ocean margin. The Intergovernmental Panel on Climate Change (IPCC) and United States Global Change Research …
The Ecological Effects Of Nitrogen Enrichment In Aridlands, 2023 University of Texas at El Paso
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 …
Nitrogen Cycling In The Lower Chesapeake Bay And Mid- And South Atlantic Bight, 2023 Old Dominion University
Nitrogen Cycling In The Lower Chesapeake Bay And Mid- And South Atlantic Bight, Yifan Zhu
OES Theses and Dissertations
Nitrogen (N) is central to marine primary production; its availability often limits the capacity and rates of primary productivity in most of the world’s oceans. Contrastingly, estuaries frequently receive anthropogenic N loading, oftentimes resulting in eutrophication, harmful algal blooms (HABs), and substantially degraded water quality. Nutrient variability in both estuaries and oceanic regimes results from meteorological forcing and physical processes, including wind-induced, tidal, and mesoscale mixing and upwelling. In this dissertation, a comprehensive investigation of N variability and cycling and its links to physical-biogeochemical processes was conducted using time-series monitoring approaches, flux estimations, satellite imaging, biogeochemical measurements, and molecular analyses. …
The Emergence Of Convergence, 2023 University of Nebraska-Lincoln
The Emergence Of Convergence, Shana M. Sundstrom, David G. Angeler, Jessica G. Ernakovich, Jorge H. Garcia, Joseph A. Hamm, Orville Huntington, Craig R. Allen
Faculty Publications
Science is increasingly a collaborative pursuit. Although the modern scientific enterprise owes much to individuals working at the core of their field, humanity is increasingly confronted by highly complex problems that require the integration of a variety of disciplinary and methodological expertise. In 2016, the U.S. National Science Foundation launched an initiative prioritizing support for convergence research as a means of “solving vexing research problems, in particular, complex problems focusing on societal needs.” We discuss our understanding of the objectives of convergence research and describe in detail the conditions and processes likely to generate successful convergence research. We use our …
Short-Term Responses Of Soil Carbon, Nitrogen, And Microbial Biomass To Cover Crop Mixtures And Monocultures, 2023 Universidade Federal dos Vales do Jequitinhonha e Mucuri
Short-Term Responses Of Soil Carbon, Nitrogen, And Microbial Biomass To Cover Crop Mixtures And Monocultures, Igor Alexandre De Souza, Amanda B. Daly, Jorg Schnecker, Nicholas D. Warren, Adalfredo Rocha Lobo Jr., Richard G. Smith, Andre Fonseca Brito, A. Stuart Grandy
Faculty Publications
Increasingly, cover crops are being adopted for the purpose of improving soil health, yet the timescale and magnitude by which living annual cover crops might modify soil chemical and biological aspects of soil health is not well understood. At the same time, there is growing interest among farmers in cover crop mixtures due to perceptions that species-rich cover crop communities will enhance soil health relative to monocultures. In a field experiment in southeast New Hampshire, we investigated how groups of cover crops grown as monocultures and mixtures for specific seasonal niches (winter/spring, summer, and fall) influenced levels of soil nitrogen …
Thames River Subwatershed Soil, Sediment, Water Data, 2023 University of Massachusetts Amherst
Thames River Subwatershed Soil, Sediment, Water Data, Justin B. Richardson, Mark J. Butler
Data and Datasets
Trace element and nutrient data are for riparian soils, suspended sediments, eddy bottom sediments, and river water collected between 2019 and 2020 in the Thames River watershed of Connecticut, USA. Trace elements and nutrients were measured using EPA 3050B digestion method and analyzed by ICP-OES or ICP-MS.
Environmental Chemical Analysis Method Optimization And Application To Northwest Cuban Marine Sediment, 2023 University of South Florida
Environmental Chemical Analysis Method Optimization And Application To Northwest Cuban Marine Sediment, Thea R. Bartlett
USF Tampa Graduate Theses and Dissertations
A method for gas chromatography tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode has been optimized to quantify 250 compounds of a variety of compound classes such as polycyclic aromatic hydrocarbons (PAHs), oxidized PAHs, organochlorinated pesticides, polychlorinated biphenyls, biomarkers (hopanes, steranes, tri-aromatic steroids, and fecal sterols), aliphatic hydrocarbons, and plastic additives. This method was validated based on available QA/QC standards using several environmental samples, both sediment and biota, and standard reference materials. This contaminant-focused method can be used as a forensic geochemistry tool to evaluate oil contamination and other contaminant histories in future research studies. When applied to …
Microbial Carbon Use Efficiency Promotes Global Soil Carbon Storage, 2023 Tsinghua University
Microbial Carbon Use Efficiency Promotes Global Soil Carbon Storage, Feng Tao, Yuanyuan Huang, Bruce A. Hungate, Stefano Manzoni, Serita D. Frey, Michael W. I. Schmidt, Markus Reichstein, Nuno Carvalhais, Philippe Ciais, Lifen Jiang, Johannes Lehmann, Ying-Ping Wang, Benjamin Z. Houlton, Bernhard Ahrens, Umakant Mishra, Gustaf Hugelius, Toby D. Hocking, Xingjie Lu, Zheng Shi, Kostiantyn Viatkin, Ronald Vargas, Yusuf Yigini, Christian Omuto, Ashish A. Malik, Guillermo Peralta, Rosa Cuevas-Corona, Luciano E. Di Paolo, Isabel Luotto, Cuijuan Liao, Yi-Shuang Liang, Vinisa S. Saynes, Xiaomeng Huang, Yiqi Luo
Faculty Publications
Soils store more carbon than other terrestrial ecosystems1,2. How soil organic carbon (SOC) forms and persists remains uncertain1,3, which makes it challenging to understand how it will respond to climatic change3,4. It has been suggested that soil microorganisms play an important role in SOC formation, preservation and loss5,6,7. Although microorganisms affect the accumulation and loss of soil organic matter through many pathways4,6,8,9,10,11, microbial carbon use efficiency (CUE) is an integrative metric that can capture the balance of these processes12,13. Although CUE has the potential to act as a predictor of variation in SOC storage, the role of CUE in SOC …
Small Community Water Systems Have The Highest Prevalence Of Mn In Drinking Water In California, Usa, 2023 Chapman University
Small Community Water Systems Have The Highest Prevalence Of Mn In Drinking Water In California, Usa, Miranda Aiken, Samantha C. Ying
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Manganese (Mn) is currently regulated as a secondary contaminant in California, USA; however, recent revisions of the World Health Organization drinking water guidelines have increased regulatory attention of Mn in drinking water due to increasing reports of neurotoxic effects in infants and children. In this study, Mn concentrations reported to California’s Safe Drinking Water Information System were used to estimate the potentially exposed population within California based on system size. We estimate that between 2011 and 2021, over 525,000 users in areas with reported Mn data are potentially exposed to Mn concentrations exceeding the WHO health-based guideline (80 μg L …
Investigation Of A Possible Switch Of Benthic Photosynthetic Organisms And Phytoplanktonic Organisms In White Point Swash, South Carolina, 2023 Coastal Carolina University
Investigation Of A Possible Switch Of Benthic Photosynthetic Organisms And Phytoplanktonic Organisms In White Point Swash, South Carolina, Nathan Easterling
Honors Theses
This research study examined the possible switch from benthic photosynthetic organisms to phytoplankton in the water column at White Point Swash, Long Bay, South Carolina, and what is causing this switch to occur. During Dr. Hannides’ and his group’s studies at this and other swashes in the past, they noticed this phenomenon of the benthic photosynthetic organisms taking over during a certain time and then the phytoplankton in the water column taking over during a different time. In this study, I measured the relative benthic macroalgal area coverage and sedimentary chlorophyll a concentration as measures of the abundance of benthic …
The Dynamics Of Sedimentary Chlorophyll Α At A High-Energy Beach, 2023 Coastal Carolina University
The Dynamics Of Sedimentary Chlorophyll Α At A High-Energy Beach, Sarah (Gray) Abel
Honors Theses
Productive sandy beaches are one of the most crucial areas serving our ecosystem today. While often overlooked in scientific research, productive beaches have many essential functions that lead to the preservation and protection of many different species as well as ecological wellness and stability. A key factor that is linked to this productivity is the presence of chlorophyll in the sediments. Piston cores of the sediments at the low-tide mark at Waties Island, South Carolina, were collected across multiple years and subsequently analyzed for chlorophyll concentrations through fluorometry after acetone extraction and acidification. Each core profile was processed to calculate …
Suboxic And Anaerobic Respiration Across A Sandy-Shore-To-Estuarine Gradient, 2023 Coastal Carolina University
Suboxic And Anaerobic Respiration Across A Sandy-Shore-To-Estuarine Gradient, Jacey Ballard
Honors Theses
Sulfate is an inorganic ion that is one of the major ions of seawater. Sulfate is also an essential reactant in microbially mediated anaerobic respiration that produces sulfide, an energy source during chemosynthesis. Sulfide is widely found in sediment, and water rich in decaying organic material, as well as hydrothermal vents. While sulfate reduction occurs extensively in muds, such as those of marshes, it is not expected to occur in sand which is much better aerated. Recent research in our group documented extensive sub aerobic respiration in coastal sands which suggests that sulfate reduction may have also been happening. This …
The Impact Of Glacial Proximity On The Elemental Composition Of Leachate Derived From Sediment Weathering, 2023 University of Nebraska at Omaha
The Impact Of Glacial Proximity On The Elemental Composition Of Leachate Derived From Sediment Weathering, Karoline Ford
Theses/Capstones/Creative Projects
This study assesses chemical weathering trends as they relate to glacial retreat. The chemical environment of surfaces exposed to the atmosphere differs significantly from beneath a glacier. As a glacier melts, changes to the biogeochemical processes generate environmental gradients. This study analyzed chemical weathering signals at different distances from a glacial front by comparing the elemental composition of leachate derived from sediments in southeastern Greenland. Samples from proglacial, nonglacial, and moraine locations were weathered in a laboratory setting, and ion chromatography was used to determine the elemental composition of the products. Divergent trends in leachate composition were observed as distance …
Linking Decomposition Reactions In Arctic Soils To Microbial Enzyme Production, 2023 University of Texas at El Paso
Linking Decomposition Reactions In Arctic Soils To Microbial Enzyme Production, Jane Karen Martinez
Open Access Theses & Dissertations
Microbial processes such as soil enzyme production are a major driver of decomposition and a current topic of interest in arctic soils due to the effects of climate warming. Despite the advances in understanding soil enzymes, there are still knowledge gaps regarding the role of enzymes in decomposition. In this dissertation, I addressed three of those gaps in the following chapters: (Ch.2) to explore the location of enzymes within the soil matrix, (Ch.3) to identify peptides matched to soil enzymes produced by microorganisms for organic matter decomposition, and (Ch.4) understand the longevity of enzymes in the soil after microbial production. …
Spot1356 Black Rock, 2023 University of New Orleans
Spot1356 Black Rock, Robert C. Mahon, Elizabeth J. Trower, Benjamin P. Smith, Tyler A. Lincoln, Juliana Olsen-Valdez, John S. Magyar, Cedric J. Hagen
2D Wave Spectral Data, South Arm, Great Salt Lake, Utah
Data in this folder are produced by a SoFarOcean Spotter wave buoy deployed along the south arm of the Great Salt Lake, near Antelope Island State Park from the period of July 13, 2021 through June 28, 2022, in relatively shallow water, approximately 1.6m.
Dissolved Copper Distributions In The Western Mississippi Sound: Characterizing An Unrecognized Endmember, 2023 The University of Southern Mississippi
Dissolved Copper Distributions In The Western Mississippi Sound: Characterizing An Unrecognized Endmember, Megan Hansen
Honors Theses
This study examined the distribution of dissolved copper (Cu) in the western Mississippi Sound, as the element can be beneficial or harmful to organisms depending on its concentration and its chemical form. A mixing experiment eliminated flocculation as a control on Cu distributions during estuarine mixing in both dissolved and colloidal fractions. Field sampling of the western Mississippi Sound occurred during a low river discharge period, and distributions of Cu indicated conservative mixing between fresh ([Cu] ≈ 17 nM) and saline ([Cu] ≈ 2 nM) sources in mid-to-high salinities. Storm outfalls were sampled after rain events to evaluate the impact …
Spot1328 Meira Spit, 2023 University of New Orleans
Spot1328 Meira Spit, Robert C. Mahon, Elizabeth J. Trower, Benjamin P. Smith, Tyler A. Lincoln, Juliana Olsen-Valdez, John S. Magyar, Cedric J. Hagen
2D Wave Spectral Data, South Arm, Great Salt Lake, Utah
Data in this folder are produced by a SoFarOcean Spotter wave buoy deployed along the south arm of the Great Salt Lake, near Antelope Island State Park from the period of July 13, 2021 through June 28, 2022, in relatively shallow water, approximately 1.6m.
IMPORTANT NOTE: Water depths for #1328 (Miera Spit) started at ~1.7 m, but dropped rapidly to 0.9 m on July 15, 2021 and dropped further to ~0.4 m on August 17, 2021. The timing of these rapid water depth changes matches the timing of buoy location changes when the anchor was dragged inshore by waves. When …
Spot1356 Black Rock Derived Data, 2023 University of New Orleans
Spot1356 Black Rock Derived Data, Robert C. Mahon, Elizabeth J. Trower, Benjamin P. Smith, Tyler A. Lincoln, Juliana Olsen-Valdez, John S. Magyar, Cedric J. Hagen
2D Wave Spectral Data, South Arm, Great Salt Lake, Utah
Data in this folder are produced by a SoFarOcean Spotter wave buoy deployed along the south arm of the Great Salt Lake, near Antelope Island State Park from the period of July 13, 2021 through June 28, 2022, in relatively shallow water, approximately 1.6m.