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Plant Water Uptake Strategies In An Urban Green Landscape, Erica G. Almance Jan 2024

Plant Water Uptake Strategies In An Urban Green Landscape, Erica G. Almance

Earth & Environmental Sciences Theses - Archive

Urban green landscapes have been widely recognized for potentially reducing surface water pollution and flood impacts. However, the understanding of the role that plants play in partitioning the urban water cycle is still limited. We present a study in the Fort Worth Botanic Garden to understand water uptake strategies from three common urban tree species (Elderberry, Sambucus canadensis; Cherry laurel, Prunus caroliniana; and Boxelder maple, Acer negundo) from February 2023 through January 2024. Stem (N=110) isotope ratios (δ18O and δ2H) are compared to multiple endmembers, including precipitation (N=509), throughfall (N=37), and soil water (N=135) at different depths (0- 38 cm). …


A Field-Based Study Of Dust Emissivity In The Northern Chihuahuan Desert, U.S.: Testing The Preferential Dust Source Scheme, Gwenn L Harsha Jan 2024

A Field-Based Study Of Dust Emissivity In The Northern Chihuahuan Desert, U.S.: Testing The Preferential Dust Source Scheme, Gwenn L Harsha

Dissertations and Theses

We characterized spatiotemporal dust emissivity in the Northern Chihuahuan Desert (New Mexico, Texas, and Arizona, U.S.) using the Portable In-Situ Wind Erosion Lab (PI-SWERL) and measurements of soil crust strength, soil texture and soil moisture. Field-based measurements of emissivity were compared to the results of the Preferential Dust Source (PDS) scheme (Bullard et al., 2011) in the Chihuahuan Desert (Baddock et al., 2011) where 48% of satellite-observed plumes were sourced from ephemeral and dry lakes. Six landforms were tested: 1) ephemeral and 2) dry lake, 3) high and 4) low relief alluvial, and aeolian 5) sand sheet and 6) dunes. …


Can Phytoremediation-Induced Changes In The Microbiome Improve Saline/Sodic Soil And Plant Health?, Achal Neupane, Duncan Jukubowski, Douglas Fiedler, Liping Gu, Sharon A. Clay, David E. Clay, Shin-Yi Marzano Jan 2024

Can Phytoremediation-Induced Changes In The Microbiome Improve Saline/Sodic Soil And Plant Health?, Achal Neupane, Duncan Jukubowski, Douglas Fiedler, Liping Gu, Sharon A. Clay, David E. Clay, Shin-Yi Marzano

Agronomy, Horticulture and Plant Science Faculty Publications

Increasing soil salinity and/or sodicity is an expanding problem in the Northern Great Plains (NGP) of North America. This study investigated the impact of phytoremediation on the soil microbiome and if changes, in turn, had positive or negative effects on plant establishment. Amplicon sequencing and gas chromatograph/mass spectrometer analysis compared root metabolites and microbial composition of bulk vs. rhizosphere soils between two soil types (productive and saline/sodic). Beta-diversity analysis indicated that bacterial and fungal communities from both the bulk and rhizosphere soils from each soil type clustered separately, indicating dissimilar microbial composition. Plant species also influenced both root-associated bacterial and …


Probable Extirpation Of The Jackrabbit (Lepus Californicus) From Arkansas, D.B. Sasse Jan 2024

Probable Extirpation Of The Jackrabbit (Lepus Californicus) From Arkansas, D.B. Sasse

Journal of the Arkansas Academy of Science

The black-tailed jackrabbit (Lepus californicus) was first documented in Arkansas during the modern era in Franklin County in 1927. Over the next few decades records were reported from multiple counties in northwest Arkansas and the species was locally common in Benton, Crawford, and Washington counties in the 1950s. The last Arkansas record documented in the scientific literature was from 1968 and since then there have only been three credible reports, with the last being from the late 1980s. The Arkansas Game and Fish Commission solicited reports of jackrabbits from the public and failed to find evidence of them from a …


Ultrastructure Of The Biflagellated Spermatozoon In The Western Siren, Siren Nettingi (Caudata: Sirenidae), Using Scanning Electron Microscopy, S.E. Trauth Jan 2024

Ultrastructure Of The Biflagellated Spermatozoon In The Western Siren, Siren Nettingi (Caudata: Sirenidae), Using Scanning Electron Microscopy, S.E. Trauth

Journal of the Arkansas Academy of Science

I investigated the ultrastructure of the biflagellated spermatozoon of the Western Siren, Siren nettingi, using scanning electron microscopy from salamanders collected in northeastern Arkansas. My primary goal in this study was to reveal the general morphology of the distinctive sperm cell components (two axonemes, two undulating membranes, and two axial fibers), which run nearly the entire length of the spermatozoon. These remarkable gamete structures are found in members of the salamander family Sirenidae and do not conform to spermatozoal ultrastructure of any other salamander species. Moreover, the biflagellated sperm are the end product of an extraordinary assemblage of complex maturation …


History And Distribution Of The Wood Stork (Mycteria Americana) In Arkansas, R. Tumlison, L. Serviss Jan 2024

History And Distribution Of The Wood Stork (Mycteria Americana) In Arkansas, R. Tumlison, L. Serviss

Journal of the Arkansas Academy of Science

Wood Storks (Mycteria americana) were thought to be common visitors to Arkansas in the early 1900s, but observations declined mid-century. Surveys of citizen science data and other online sources indicate that numbers of unique observations and total counts of birds have increased since 2000. Storks do not breed here, but have been reported in 34 of 75 counties, and appear mostly in August and September. Birds apparently originate from Mexico. Number of observations have increased since 2016, but many of those observations include only a few birds rather than larger flocks.


An Annotated Checklist Of The Camel Crickets (Insecta: Orthoptera: Rhaphidophoridae) Of Arkansas, H.W. Robison, C.T. Mcallister Jan 2024

An Annotated Checklist Of The Camel Crickets (Insecta: Orthoptera: Rhaphidophoridae) Of Arkansas, H.W. Robison, C.T. Mcallister

Journal of the Arkansas Academy of Science

A total of 14 native species of camel crickets and one introduced taxon representing three genera (Ceuthophilus, Phrixocnemis, and Diestrammena) of the orthopteran family Rhaphidophoridae, are herein reported from Arkansas. The most diverse genus was Ceuthophilus, with 13 native species, while Phrixocnemis had one native species, and Diestrammena, formerly Tachycines, was represented by one introduced species. This updated checklist is intended to be of use to entomologists, naturalists, professional biologists, and resource managers in evaluating the biodiversity of Arkansas. State distributional maps are provided for each species listed by county, and habitats are discussed in which each species was taken …


Fish Leeches Of Arkansas, D.J. Richardson, W.E. Moser, C.T. Mcallister, S.P. Lawson, H.W. Robison Jan 2024

Fish Leeches Of Arkansas, D.J. Richardson, W.E. Moser, C.T. Mcallister, S.P. Lawson, H.W. Robison

Journal of the Arkansas Academy of Science

Recent collection within Arkansas greatly enlarges the knowledge concerning hosts and distributions of fish leeches within the state. The natural history of the 6 species of fish leeches known from Arkansas (Placobdella montifera, Placobdella pediculata, Cystobranchus klemmi, Cystobranchus verrilli, Myzobdella lugubris, and Myzobdella reducta) is reviewed and updated and molecular data are provided.


Origin Of Carbonate Mud Mounds In Southwestern Missouri, Jared Mcavoy Jan 2024

Origin Of Carbonate Mud Mounds In Southwestern Missouri, Jared Mcavoy

Graduate Theses/Dissertations

Small carbonate mud mounds are found in Lower Mississippian strata of southwestern Missouri. These compare favorably with larger mounds, known as Waulsortian mounds, located in the Meuse River valley of southern Belgium. The origin of Waulsortian and similar mounds is unknown, but they commonly are interpreted as accumulations of mud, where the presence of biological organisms responsible for supposed bio-construction remains uncertain. Alternative hypotheses are that these may have been non-cohesive slump or cohesive slide masses. Multiple techniques, including δ13C and δ18O isotopic analyses and unmanned aerial vehicle photography, were used to determine the most feasible working hypothesis. Determining the …


Water Quality Of A Karstic Shallow Aquifer In Greene And Lawrence Counties, Missouri, Claudia Patricia Colmenero Chacon Jan 2024

Water Quality Of A Karstic Shallow Aquifer In Greene And Lawrence Counties, Missouri, Claudia Patricia Colmenero Chacon

Graduate Theses/Dissertations

A water quality investigation in the Springfield Plateau aquifer of Greene and Lawrence counties, Missouri, was conducted. Water samples from eleven springs were collected at regular intervals during 2023 to determine major water quality parameters: total dissolved solids (TDS), alkalinity, calcium (Ca), magnesium (Mg), sodium (Na), sulfate (SO4), chloride (Cl) and nitrate-nitrogen (NO3-N), along with per- and poly-fluorinated alkali substances (PFAS) from spring sediments. Nitrate-nitrogen was analyzed because of the importance for environmental health (e.g. to avoid eutrophication). Springs samples were separated by land use into urban and rural samples. In addition, Springfield Plateau water quality …


Impacts Of Anthropogenic Sedimentation On Shell-Bed Habitats In Lake Tanganyika, Africa, Michael Soreghan, Andrew Cohen, Michael M. Mcglue, Kevin M. Yeager, Emily Ryan, Alison Johns, Ishmael Kimirei Jan 2024

Impacts Of Anthropogenic Sedimentation On Shell-Bed Habitats In Lake Tanganyika, Africa, Michael Soreghan, Andrew Cohen, Michael M. Mcglue, Kevin M. Yeager, Emily Ryan, Alison Johns, Ishmael Kimirei

Earth and Environmental Sciences Faculty Publications

Lake Tanganyika, in central Africa, contains a diverse and endemic fauna under threat from global climate change, overfishing, and nearshore sediment pollution. Previous studies of sediment pollution focused justifiably on impacts along rocky shorelines where diversity is high, but Lake Tanganyika also contains widespread shelly accumulations (shell beds) unprecedented in the modern East African lakes, but where impacts are less con- strained. Here we integrate multiple datasets from three sites along the Tanzanian shoreline to explore how variation in sedimentation rates and sediment quality impacts shell-bed substrate and diversity and abundance of ostracodes and sponges across sites that exhibit varying …


Early Oligocene Record Of An “Iceberg Alley” In The Weddell Sea From Quartz Sand Microtextural Analysis At Odp Site 696, Victoria Hojnacki, Sandra Passchier Jan 2024

Early Oligocene Record Of An “Iceberg Alley” In The Weddell Sea From Quartz Sand Microtextural Analysis At Odp Site 696, Victoria Hojnacki, Sandra Passchier

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The greenhouse to icehouse transition at the Eocene-Oligocene boundary (34 Ma) marked the appearance of continental-scale glaciation in Antarctica. The material recovered from Ocean Drilling Program Site 696 is the only record spanning this major climatic shift in the Weddell Sea region. Using scanning electron microscopy, quartz microtextures in 13 samples across the Eocene-Oligocene transition were analyzed to understand the degree of glacial modification and the transportation history of the >150 µm material. The quartz grains were visually grouped, characterized, and interpreted by grain outline, relief, and surface microtextures. Glacial textures are present throughout the entire interval (34.4–33.2 Ma), with …


Geological And Environmental Sciences - 2024, Dept. Of Geological And Environmental Sciences Jan 2024

Geological And Environmental Sciences - 2024, Dept. Of Geological And Environmental Sciences

Geological and Environmental Sciences News

  • Greetings from the Department Chair
  • Thank You to our Donors
  • Faculty Updates
  • Emeritus Faculty Updates
  • MGRRE Updates
  • MGS Updates
  • Geosciences Advisory Council
  • Student Clubs
  • Awards and Honors, 2024
  • Department Graduates
  • Publications 2023–24


Pleated Plasma Membrane Complex In Spermatids Of The Western Siren, Siren Nettingi (Caudata: Sirenidae), S.E. Trauth Jan 2024

Pleated Plasma Membrane Complex In Spermatids Of The Western Siren, Siren Nettingi (Caudata: Sirenidae), S.E. Trauth

Journal of the Arkansas Academy of Science

I investigated the pleated plasma membrane complex of linear folds and biflagellar entities in developing spermatids of the Western Siren, Siren nettingi. My primary goal was to reveal the ultrastructural morphology of these distinctive cellular folds (usually 8 in number) as they support the flagellar formation of biflagellated sperm found in this salamander and in other members in the family Sirenidae. My results reveal that the biflagellar components (2 sets of axonemes, undulating membranes, and axial fibers), termed biflagellar complex, develop between folds or are attached onto these folds. The folds themselves are transitory and do not directly contribute to …


Building Detailed And Accurate Whole-Plant Concepts: A Morphometrics-Informed Reconstruction Of A Zosterophyll From The Lower Devonian Of Wyoming, Samar R. El-Abdallah Jan 2024

Building Detailed And Accurate Whole-Plant Concepts: A Morphometrics-Informed Reconstruction Of A Zosterophyll From The Lower Devonian Of Wyoming, Samar R. El-Abdallah

Cal Poly Humboldt theses and projects

The fragmentary state of plant fossils and the modular organization of plants make whole-plant reconstructions of fossil species desirable and feasible. Such reconstructions are key for integrating fossil species in systematic studies. The ca. 410 Ma Beartooth Butte Formation of Wyoming (USA) hosts the only rich Early Devonian plant assemblages in western North America, which fills a major gap in the phytogeography of this interval. I construct a whole-plant concept for a new zosterophyll from the Beartooth Butte Formation based on a detailed morphometric study. More than 600 fragments of the new zosterophyll were observed and 200 of those were …


The Hutton Project: Long-Term Agricultural Impacts On Soil Loss And Carbon Dynamics In Eastern South Dakota, Eli Halverson Jan 2024

The Hutton Project: Long-Term Agricultural Impacts On Soil Loss And Carbon Dynamics In Eastern South Dakota, Eli Halverson

Electronic Theses and Dissertations

Long-term and intensified agricultural land management has resulted in increased rates of soil erosion and has altered much of the carbon cycle at regional and global scales. Anthropogenic degradation of soil resources is a barrier to sustainable production, soil functioning, and ecosystem services. It is difficult to quantify the scope of pedogenic changes due to the lack of legacy data and short temporal scales. This study utilized decades to century-old soil information to quantify historical soil erosion losses and changes in soil carbon pools of eastern South Dakota soils. The results show that soils in the region have been significantly …


Impacts Of Cover Crops And Diversified Crop Rotations On Soil Biochemical Properties, Hydrophysical Characteristics, And Water Dynamics In Long-Term No-Till Cropping Systems, Sainfort Vital Jan 2024

Impacts Of Cover Crops And Diversified Crop Rotations On Soil Biochemical Properties, Hydrophysical Characteristics, And Water Dynamics In Long-Term No-Till Cropping Systems, Sainfort Vital

Electronic Theses and Dissertations

This research assessed the impacts of crop rotations and cover crops on the soil's biochemical and hydrophysical properties within long-term no-till systems. The research was conducted at the Southeast Research Farm, near Beresford, South Dakota. The crop rotations contain two levels: 4-year corn (Zea mays L.)-soybean (Glycine max L.)-oat (Avena sativa L.)-rye (Secale cereale L.) (CSOR) and 2-year corn-soybean (CS) rotations. The cover crop factors also had two levels within each rotation treatment: cover crops (CC) and no cover crops (NCC). All plots were managed under long-term no-till (NT), with soils mapped as Egan silty clay loam (fine-silty, mixed, superactive, …


Plant Available Water Drives Semi-Arid Forage Quality And Quantity In A Common Garden Greenhouse Experiment, Parker J. Witt Jan 2024

Plant Available Water Drives Semi-Arid Forage Quality And Quantity In A Common Garden Greenhouse Experiment, Parker J. Witt

Electronic Theses and Dissertations

Rangeland forage nutrition and biomass production are integral components of sustainable livestock grazing systems and are controlled by soil quality and precipitation. I examined the effects of precipitation on growth and nutrition of three forage species in four different soils that span the longitudinal moisture gradient in South Dakota. I grew little bluestem (Schizachyrum scoparium), western wheatgrass (Pascopyrum smithii), and smooth brome (Bromus inermis) in soils representing the eastern tallgrass/mid-grass prairie (Brookings, 700 mm avg. precipitation.), an eastern mid-grass prairie (Highmore, 550 mm avg. precipitation.), a western mid-grass prairie (Cottonwood, 450 mm avg. precipitation.), and a western mid-grass/short-grass prairie (Sturgis, …


Co-Location Of Seaweed Farming With Offshore Wind Energy: A Quick Scoping Review, Brianna Coffey, Cortni Borgerson, Pankaj Lal, Colette J. Feehan Jan 2024

Co-Location Of Seaweed Farming With Offshore Wind Energy: A Quick Scoping Review, Brianna Coffey, Cortni Borgerson, Pankaj Lal, Colette J. Feehan

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Seaweed farming is increasingly recognized as a sustainable marine resource management opportunity, but it also poses socioeconomic and environmental risks that require careful evaluation. This quick scoping review (QSR) examines the current state of knowledge on upscaling seaweed farming through co-location with offshore wind energy production. A total of 240 published records from 2001 to 2022 were analyzed, including studies on general seaweed farming and its integration with offshore wind energy, both of which have shown a significant increase in annual publication rates over time. Geographically, the majority of studies on general seaweed farming were conducted in Asia, while most …


Cataloguing Minerals, Part Two: Re-Imagining Mineral Catalogue Descriptions To Address Colonial Legacies, Carrie Robbins, Selby Hearth, Marianne Weldon, Aha Anderson, Rosa Bieber-Stanley, April Chernila, Helen Christ, Hannah Cosgrove, Morgan Hanson-Rosenberg, Carly Hill, Maya Hofstetter, Emily Lazo, Izzie Ludlow, Samantha Lyster, Rachel Myers, Jasper Nash, Georgia Reed, Julia Saint- Amour Jan 2024

Cataloguing Minerals, Part Two: Re-Imagining Mineral Catalogue Descriptions To Address Colonial Legacies, Carrie Robbins, Selby Hearth, Marianne Weldon, Aha Anderson, Rosa Bieber-Stanley, April Chernila, Helen Christ, Hannah Cosgrove, Morgan Hanson-Rosenberg, Carly Hill, Maya Hofstetter, Emily Lazo, Izzie Ludlow, Samantha Lyster, Rachel Myers, Jasper Nash, Georgia Reed, Julia Saint- Amour

Geology Faculty Research and Scholarship

Minerals are uniquely tied to colonialism, labour, and environment; however, those relationships have traditionally not been described in mineral catalogues – an omission that limits curators’ ability to account for mineral histories. This paper re-imagines mineral cataloguing practices to restore historical, cultural, and environmental contexts that were stripped away. We describe the roles of citations; linked data; provenience and provenance histories; non-standardized and ‘unapproved’ nomenclatures; positionality; and the need to label archival silences. We examine the risks and practical limitations that arise in attempting to turn this colonial tool against itself. In discussing these issues, we contribute to ongoing dialogues …


Improving Accessibility And Understanding: Studying The Impact Of Human Activities And Dam Removals On Anadromous Fish Species In The Pacific Northwest, Adia F. Bennett Jan 2024

Improving Accessibility And Understanding: Studying The Impact Of Human Activities And Dam Removals On Anadromous Fish Species In The Pacific Northwest, Adia F. Bennett

Scripps Senior Theses

Human activities in North American watersheds have significantly impacted anadromous fish, causing some species of salmon and steelhead to become threatened and endangered. These fish hold ecological, cultural, and economic importance, yet factors such as habitat destruction, overfishing, pollution, climate change, and hydroelectric dams continue to degrade populations. Dams are particularly harmful to anadromous fish, sparking a recent movement advocating for dam removals. This study uses NOAA’s 2022 Biological Viability Assessment to examine the response of anadromous fish to recent dam removals in the Pacific Northwest. Four populations were selected to analyze due to their interaction with sites that had …


Plasmid-Borne Biosynthetic Gene Clusters Within A Permanently Stratified Marine Water Column, Paraskevi Mara, David Geller-Mcgrath, Elizabeth A. Suter, Gordon T. Taylor, Maria G. Pachiadaki, Virginia P. Edgcomb Jan 2024

Plasmid-Borne Biosynthetic Gene Clusters Within A Permanently Stratified Marine Water Column, Paraskevi Mara, David Geller-Mcgrath, Elizabeth A. Suter, Gordon T. Taylor, Maria G. Pachiadaki, Virginia P. Edgcomb

BCES: Faculty Publications

Plasmids are mobile genetic elements known to carry secondary metabolic genes that affect the fitness and survival of microbes in the environment. Well-studied cases of plasmidencoded secondary metabolic genes in marine habitats include toxin/antitoxin and antibiotic biosynthesis/resistance genes. Here, we examine metagenome-assembled genomes (MAGs) from the permanently-stratified water column of the Cariaco Basin for integrated plasmids that encode biosynthetic gene clusters of secondary metabolites (smBGCs). We identify 16 plasmid-borne smBGCs in MAGs associated primarily with Planctomycetota and Pseudomonadota that encode terpenesynthesizing genes, and genes for production of ribosomal and non-ribosomal peptides. These identified genes encode for secondary metabolites that are …


Ontogenetically Driven Changes In The Endocranial Anatomy Of Maiasaura Peeblesorum And Its Implications For Sensory Functions, Emma Puetz Jan 2024

Ontogenetically Driven Changes In The Endocranial Anatomy Of Maiasaura Peeblesorum And Its Implications For Sensory Functions, Emma Puetz

Masters Theses

"Hadrosaurids exhibited extreme morphological diversity and behavioral characteristics that can be compared with other, closely related members of Dinosauria – particularly through the study of neuroanatomy. X-ray CT generated endocrania of the Late Cretaceous saurolophine hadrosaur Maiasaura peeblesorum, known as the “good mother” dinosaur, offers a unique opportunity to compare complex ecological behaviors between non-avian dinosaurs and their modern archosaur relatives. The 3D reconstruction software ORS Dragonfly provided linear and volumetric measurements taken from the digital cranial endocast and endosseous labyrinths of three ontogenetically varied M. peeblesorum specimens from the Two Medicine Formation in Montana that were used to …


Supply And Consumption Of Dissolved Organic Phosphorus Across The Subtropical Indian Ocean, Corinne Richard Jan 2024

Supply And Consumption Of Dissolved Organic Phosphorus Across The Subtropical Indian Ocean, Corinne Richard

Honors Theses and Capstones

The Indian Ocean is an understudied region for marine phosphorus (P) biogeochemistry. Emerging evidence indicates marine phytoplankton can adapt to decreasing supplies of inorganic P, a required nutrient for growth, by alternatively utilizing organic forms of P. Here we investigate the dissolved organic phosphorus concentration ([DOP]) distribution across the southern Indian Ocean using observations collected on the I05 US GO-SHIP Cruise (2023) across ~33ºS latitude. We quantify the longitudinal variability of [DOP] in the upper 350 m of the Indian Ocean and infer its rate of biological consumption from surface waters, contributing as an organic nutrient to sustain marine autotrophs …


Re-Evaluating Hydrogen Sulfide As A Sink For Cadmium And Zinc In The Oxic To Suboxic Upper Water Column Of The Pacific Ocean, N. R. Buckley, E. E. Black, J. A. Kenyon, N. T. Lanning, M. Sieber, T. M. Conway, J. N. Fitzsimmons, G. A. Cutter Jan 2024

Re-Evaluating Hydrogen Sulfide As A Sink For Cadmium And Zinc In The Oxic To Suboxic Upper Water Column Of The Pacific Ocean, N. R. Buckley, E. E. Black, J. A. Kenyon, N. T. Lanning, M. Sieber, T. M. Conway, J. N. Fitzsimmons, G. A. Cutter

OES Faculty Publications

Hydrogen sulfide is produced by heterotrophic bacteria in anoxic waters and via carbonyl sulfide hydrolysis and phytoplankton emissions under oxic conditions. Apparent losses of dissolved cadmium (dCd) and zinc (dZn) in oxygen minimum zones (OMZs) of the Atlantic and Pacific Oceans have been attributed to metal-sulfide precipitation formed via dissimilatory sulfate reduction. It has also been argued that such a removal process could be a globally important sink for dCd and dZn. However, our studies from the North Pacific OMZ show that dissolved and particulate sulfide concentrations are insufficient to support the removal of dCd via precipitation. In contrast, apparent …


Editorial: The Marine Iodine Cycle, Past, Present, And Future, Rosie Chance, Gregory A. Cutter, Dalton S. Hardisty, Anoop S. Mahajan Jan 2024

Editorial: The Marine Iodine Cycle, Past, Present, And Future, Rosie Chance, Gregory A. Cutter, Dalton S. Hardisty, Anoop S. Mahajan

OES Faculty Publications

In this Research Topic, we bring together ten articles from the diverse research communities interested in the marine iodine cycle, including paleoceanographers, atmospheric chemists, and biogeochemists. The physical chemistry underpinning iodine’s chemical speciation and transformations in the ocean is reviewed by Luther; this paper provides a theoretical basis for the field observations presented in this Research Topic.


Interpreting An Archaean Paleoenvironment Through 3d Imagery Of Microbialites, Cecilia M. Howard, Nathan D. Sheldon, Selena Y. Smith, Nora Noffke Jan 2024

Interpreting An Archaean Paleoenvironment Through 3d Imagery Of Microbialites, Cecilia M. Howard, Nathan D. Sheldon, Selena Y. Smith, Nora Noffke

OES Faculty Publications

While stromatolites, and to a lesser extent thrombolites, have been extensively studied in order to unravel Precambrian (>539 Ma) biological evolution, studies of clastic-dominated microbially induced sedimentary structures (MISS) are relatively scarce. The lack of a consolidated record of clastic microbialites creates questions about how much (and what) information on depositional and taphonomic settings can be gleaned from these fossils. We used μCT scanning, a non-destructive X-ray-based 3D imaging method, to reconstruct morphologies of ancient MISS and mat textures in two previously described coastal Archaean samples from the ~3.48 Ga Dresser Formation, Pilbara, Western Australia. The aim of this …


A Proxy System Modeling Approach To Combining Tree-Ring And Sediment-Based Paleotempestological Records, Elizabeth J. Wallace, Sylvia Dee, Joshua Bregy, Kerry A. Emanuel Jan 2024

A Proxy System Modeling Approach To Combining Tree-Ring And Sediment-Based Paleotempestological Records, Elizabeth J. Wallace, Sylvia Dee, Joshua Bregy, Kerry A. Emanuel

OES Faculty Publications

The short and biased observational record of tropical cyclones (TCs) limits scientific understanding of how these destructive storms respond to climate forcing. Paleohurricane records use natural archives (tree rings, coarse-grained sediment) to reconstruct TC properties (frequency and intensity of rainfall, wind) over the past few hundreds to thousands of years. However, different sensitivities and sampling biases in the various paleohurricane proxies restrict our ability to compile these records into regional or basin-scale TC estimates. Here we test how well pseudo tree-ring records of paleohurricanes capture TC rainfall and occurrence. Using a large set of statistically downscaled storms forced with the …


Submarine Groundwater Discharge At A Mega-Tidal Beach, Raymond D. Craddock, Aaron A. Mohammed, Joseph J. Tamborski, Barret L. Kurylyk Jan 2024

Submarine Groundwater Discharge At A Mega-Tidal Beach, Raymond D. Craddock, Aaron A. Mohammed, Joseph J. Tamborski, Barret L. Kurylyk

OES Faculty Publications

Tidally influenced groundwater systems in coastal environments represent important mixing zones of fresh groundwater and circulating seawater, manifesting as submarine groundwater discharge (SGD). Water circulation induced by tidal pumping enhances the exchange of chemicals between aquifers and coastal waters and thereby influences the biogeochemistry of coastal zones. Here, we report the results of an SGD field study conducted at a steep, mega-tidal sand and gravel beach along the Canadian coast of the Bay of Fundy, a region with the world's highest tides (semi-diurnal tidal ranges exceeding 10 m). Several physical and geochemical measurement techniques were employed to document the spatiotemporal …


Heterogeneity Of Nitrogen Fixation In The Mesopelagic Zone Of The South China Sea, Siqi Wu, Xianhui Sean Wan, Moge Du, Xirong Chen, Corday R. Selden, Mar Benavides, Sophie Bonnet, Carolin R. Löscher, M. Robert Hamersley, Margaret R. Mulholland, Xiuli Yan, Shuh-Ji Kao Jan 2024

Heterogeneity Of Nitrogen Fixation In The Mesopelagic Zone Of The South China Sea, Siqi Wu, Xianhui Sean Wan, Moge Du, Xirong Chen, Corday R. Selden, Mar Benavides, Sophie Bonnet, Carolin R. Löscher, M. Robert Hamersley, Margaret R. Mulholland, Xiuli Yan, Shuh-Ji Kao

OES Faculty Publications

Biological dinitrogen (N₂) fixation, the energetically expensive conversion of N₂ gas to ammonia, plays an essential role in balancing the nitrogen budget in the ocean. Accumulating studies show detectable N₂ fixation rates below the euphotic zone in various marine systems, revealing new insights of marine N₂ fixation. However, the reported rates are highly variable and frequently fall close to detection limits, raising the question of the ubiquity and significance of N₂ fixation in the global dark ocean. Using highly sensitive isotopic labeling incubation including a set of control incubations, we confirm the occurrence of mesopelagic N₂ fixation in the South …