Digital Commons Network^™

Plant And Microbial Responses To Repeated Cu(Oh)2 Nanopesticide Exposures Under Different Fertilization Levels In An Agro-Ecosystem, Marie Simonin, Benjamin P. Colman, Weiyi Tang, Jonathan D. Judy, Steven M. Anderson, Christina M. Bergemann, Jennifer D. Rocca, Jason M. Unrine, Nicolas Cassar, Emily S. Bernhardt

Plant and Soil Sciences Faculty Publications

The environmental fate and potential impacts of nanopesticides on agroecosystems under realistic agricultural conditions are poorly understood. As a result, the benefits and risks of these novel formulations compared to the conventional products are currently unclear. Here, we examined the effects of repeated realistic exposures of the Cu(OH)₂ nanopesticide, Kocide 3000, on simulated agricultural pastureland in an outdoor mesocosm experiment over 1 year. The Kocide applications were performed alongside three different mineral fertilization levels (Ambient, Low, and High) to assess the environmental impacts of this nanopesticide under low-input or conventional farming scenarios. The effects of Kocide over time were …

Hardbottom Characterization And Relationship To The Geologic Framework In Long Bay, South Carolina, Cathryn J. Wheaton

Electronic Theses and Dissertations

Hardbottom seafloor is a common element among sediment-starved portions of the inner continental shelf along the U.S. Atlantic margin. These areas are characterized by indurated sediment surfaces that are heavily altered by biological and physical processes. Long Bay, in northeastern South Carolina, offers ideal environmental conditions for hardbottom exposure with only patchy Holocene sand deposits, interspersed with extensive hardbottom areas. Here we use high-resolution multibeam bathymetry, CHIRP subbottom profiling and electrical resistivity data, along with surficial sediment samples, hardbottom thin sections, and water column radioisotope (radon-222) analysis to investigate the origin and geologic framework of a region of hardbottom seafloor …

The Efficacy Of Raw Malangali Kaolin Clay In The Adsorptive Removal Of Cadmium And Cobalt Ions From Water, Nyemaga Masanje Malima, Esther Hellen Lugwisha, Alinanuswe Simon Mwakaboko

Tanzania Journal of Science

The suitability of raw Malangali kaolin (RMK) clay for the removal of cadmium and cobalt ions from water was investigated using a batch technique whereas the characterization of adsorbent material was performed by XRD, XRF, ATR-FTIR and N2 physisorption techniques. Various experimental parameters were tested for the effectiveness of RMK in removing heavy metals whereby quantitative determination of both Cd2+ and Co2+ ions has shown that, the factors such as adsorbent particle size, solution pH, contact time, adsorbent dose as well as initial metal ion concentration had significant effects on the adsorption processes. The equilibrium data described by Langmuir and …

Relationships Between Landscape Constraints And A Crayfish Assemblage With Consideration Of Competitor Presence, Joshua B. Mouser, Robert Mollenhauer, Shannon K. Brewer

United States Geological Survey: Staff Publications

Aim: Crayfish are globally diverse and one of the most important taxa in North American streams. Despite their importance, many species are of conservation concern and efforts to improve conditions are limited. Here, we address two major impediments to improving conditions: (a) our lack of knowledge of the interplay among natural landscape and human-induced changes; and (b) a very limited understanding of how species interactions affect overall crayfish distributions.

Location: Ozark Highlands ecoregion, USA.

Methods: We used both existing data and field-collected data to examine the relationships between 12 Faxonius species and physicochemical variables at multiple spatial scales. Data were …

Genome-Wide Atlas Of Alternative Polyadenylation In The Forage Legume Red Clover, Manohar Chakrabarti, Randy D. Dinkins, Arthur G. Hunt

Plant and Soil Sciences Faculty Publications

Studies on prevalence and significance of alternative polyadenylation (APA) in plants have been so far limited mostly to the model plants. Here, a genome-wide analysis of APA was carried out in different tissue types in the non-model forage legume red clover (Trifolium pratense L). A profile of poly(A) sites in different tissue types was generated using so-called ‘poly(A)-tag sequencing’ (PATseq) approach. Our analysis revealed tissue-wise dynamics of usage of poly(A) sites located at different genomic locations. We also identified poly(A) sites and underlying genes displaying APA in different tissues. Functional categories enriched in groups of genes manifesting APA between …

Old And Recent Processes In A Warm And Humid Desert Hypogene Cave: ‘A’Rak Na‘Asane, Israel, Amos Frumkin, Shlomi Aharon, Uri Davidovich, Boaz Langford, Yoav Negev, Micka Ullman, Anton Vaks, Shemesh Ya‘Aran, Boaz Zissu

International Journal of Speleology

Recent environmental processes are studied in ʻA’rak Naʻasane Cave at the northern Judean Desert, Israel. The outer zone of the cave is heavily influenced by the outside environment through a large entrance, facilitating entry of air flow, fauna and humans, with minor cave-forming modifications. Conversely, the inner cave sustains humid and warm conditions, favoring modifications by condensation corrosion of convective air flow, associated with deposition of popcorn speleothems at the lower parts of dissolution pockets. The warm humid air of the inner cave may be associated with an underlying thermal water table. Active condensation corrosion is decreasing, possibly because of …

Responses Of Non-Native Earthworms To Experimental Eradication Of Garlic Mustard And Implications For Native Vegetation, Kristina A. Stinson, Serita D. Frey, M. R. Jackson, E. Coates-Connor, Mark A. Anthony, K. Martinez

Faculty Publications

Recent studies in invasion biology suggest that positive feedback among two or more introduced organisms facilitate establishment within a new range and drive changes in native plant communities. Here, we experimentally tested for relationships between native plants and two non-native organisms invading forest habitats in North America: garlic mustard (Alliaria petiolata, Brassicaceae) and earthworms. In two forested sites, we compared understory vegetation and earthworm biomass in plots where garlic mustard was removed for three years, plots without garlic mustard invasion, and plots invaded by garlic mustard that was not removed. Earthworm biomass was highest in the plots with garlic mustard, …

Differential Responses Of Carbon-Degrading Enzyme Activities To Warming: Implications For Soil Respiration, Ji Chen, Yiqi Luo, Pablo García-Palacios, Junji Cao, Marina Dacal, Xuhui Zhou, Jianwei Li, Jianyang Xia, Shuli Niu, Huiyi Yang, Shelby Shelton, Wei Guo, Kees Jan Van Groenigen

Agricultural and Environmental Sciences Faculty Research

Extracellular enzymes catalyze rate-limiting steps in soil organic matter decomposition, and their activities (EEAs) play a key role in determining soil respiration (SR). Both EEAs and SR are highly sensitive to temperature, but their responses to climate warming remain poorly understood. Here, we present a meta-analysis on the response of soil cellulase and ligninase activities and SR to warming, synthesizing data from 56 studies. We found that warming significantly enhanced ligninase activity by 21.4% but had no effect on cellulase activity. Increases in ligninase activity were positively correlated with changes in SR, while no such relationship was found for cellulase. …

Variation In Home Range Size And Patterns In Adult Female American Crocodiles Crocodylus Acutus, Jeffrey S. Beauchamp, Kristen M. Hart, Michael S. Cherkiss, Frank J. Mazzotti

United States Geological Survey: Staff Publications

The American crocodile Crocodylus acutus is a threatened species that uses relatively deep, open-water habitats with low salinity. Adult female American crocodiles nest on sandy coastal beaches, islands or human-made berms, assist in the hatching process, and can travel long distances to nesting habitat. We satellite-tracked 15 adult female American crocodiles in 2 hydrologically distinct areas in Everglades National Park, Florida, USA, to quantify the home range sizes, test for intraspecific differences in home range and core area size and structure, and identify important crocodile high-use areas. Overall home ranges (95% kernel density estimate; KDE) for adult female crocodiles in …

Litter Identity Affects Assimilation Of Carbon And Nitrogen By A Shredding Caddisfly, Adam C. Siders, Zacchaeus G. Compson, Bruce A. Hungate, Paul Dijkstra, George W. Koch, Adam S. Wymore, A. Stuart Grandy, Jane C. Marks

Faculty Publications

Ecologists often equate litter quality with decomposition rate. In soil and sediments, litter that is rapidly decomposed by microbes often has low concentrations of tannin and lignin and low C:N ratios. Do these same traits also favor element transfer to higher trophic levels in streams, where many insects depend on litter as their primary food source? We test the hypothesis that slow decomposition rates promote element transfer from litter to insects, whereas rapid decomposition favors microbes. We measured carbon and nitrogen fluxes from four plant species to a leaf-shredding caddisfly using isotopically labeled litter. Caddisflies assimilated a higher percentage of …

Using Geological Facies To Estimate Chromate Sorption To Soils, Victoria Smith, Daja Scurlock, Chauntilena Butler, Eddie Hollins, Kennedy Smith, Tim Spearman, Christina Fulghum, John Dickson, Daniel I. Kaplan, Miles Denham, Garriet Smith

Journal of the South Carolina Academy of Science

Quantifying the extent to which contaminant metals bind to subsurface soils is important for risk assessment, the tendency for a contaminant to migrate, and developing environmental remediation strategies. Unfortunately, subsurface soils vary widely in their composition, which in turn affect their tendency to bind metals. The hypothesis of this study was predicated on how a better understanding of geological facies would reduce uncertainty associated with predicting contaminant metal sorption. Facies are layers of sediment deposited in the subsurface due to similar depositional conditions, including energy of an overlying waterway. As such, facies are expected to have similar assemblages of minerals, …

Volcanic Glass As A Paleoenvironmental Proxy: Comparing Preparation Methods On Ashes From The Lee Of The Cascade Range In Oregon, Usa, Tessa Boe Carlson

Dissertations and Theses

Deuterium ratios (δD) of hydrated volcanic glass have been used to reconstruct paleoenvironments, although the reliability and proper sample preparation protocol have been debated. In this study, hydrated volcanic ash samples from the lee of the Cascades were prepared using two separate methods. Method 1 involves sonicating and rinsing samples with hydrochloric acid (HCl) followed by hand-selection of glass shards (125-212µm). Method 2 requires hydrochloric acid (HCl) and hydrofluoric acid (HF) abrasion as well as heavy liquid separation of shards (70-150µm). Method 2 produced more consistent results with decreased intra-replicate variability in both water content (-0.92 wt. %) and deuterium …

Effects Of Natural And Anthropogenic Forcing On Marsh Channel Evolution, Jeremiah Robinson

LSU Master's Theses

Wetlands have many ecological and physical properties that are essential for coastal communities. These ecosystems sustain local economies, provide essential habitats, are a source of numerous ecological and biological services, and protect coastal populations from storms. Of the many wetland types, salt marshes are among the most vulnerable to environmental changes. Salt marshes quickly respond to natural and human-driven perturbations and their high rate of loss in the last century is cause for concern.

In this project the rate of marsh loss driven by channel widening was measured through a comparative analysis of modern high resolution images and historic aerial …

Mainland Southeast Asia In The Longue Durée: A Zooarchaeological Test Of The "Broad Spectrum Revolution" In Northern Thailand, Cyler Norman Conrad

Anthropology ETDs

In northern Thailand, previous zooarchaeological research suggests that hunter-gatherers consumed a broad diversity of animal resources during the Pleistocene-Holocene transition and afterwards (Gorman 1971a). This is a pattern characteristic of Kent Flannery’s (1969) “broad spectrum revolution” hypothesis. Based primarily on presence and absence evidence, faunal assemblages in northern Thailand typically include species of mammals, reptiles, birds, fish and shellfish, suggesting that prehistoric foragers consumed a wide range of taxa within this mainland Southeast Asian tropical environment. Although zooarchaeological analyses commonly identify this pattern within prehistoric cave and rockshelter sites, past investigations have 1) not attempted to formally test Flannery’s hypothesis, …

Coupling Toxicokinetic–Toxicodynamic And Population Models For Assessing Aquatic Ecological Risks To Time-Varying Pesticide Exposures, Glen Thursby, Keith Sappington, Matthew Etterson

United States Environmental Protection Agency: Publications

Population modeling evaluations of pesticide exposure time series were compared with aspects of a currently used risk assessment process. The US Environmental Protection Agency’s Office of Pesticide Programs models daily aquatic 30-yr pesticide exposure distributions in its risk assessments, but does not routinely make full use of the information in such time series.We used mysid shrimp Americamysis bahia toxicity and demographic data to demonstrate the value of a toxicokinetic– toxicodynamic model coupled with a series of matrix population models in risk assessment refinements. This species is a small epibenthic marine crustacean routinely used in regulatory toxicity tests. We demonstrate how …

Identification Of Erosional Terraces On Seamounts: Implications For Interisland Connectivity And Subsidence In The Galápagos Archipelago, Darin M. Schwartz, S. Adam Soule, V. Dorsey Wanless, Meghan R. Jones

Geosciences Faculty Publications and Presentations

Shallow seamounts at ocean island hotspots and in other settings may record emergence histories in the form of submarine erosional terraces. Exposure histories are valuable for constraining paleo-elevations and sea levels in the absence of more traditional markers, such as drowned coral reefs. However, similar features can also be produced through primary volcanic processes, which complicate the use of terraced seamounts as an indicator of paleo-shorelines. In the western Galápagos Archipelago, we utilize newly collected bathymetry along with seafloor observations from human-occupied submersibles to document the location and depth of erosional terraces on seamounts near the islands of Santiago, Santa …

Spatial And Temporal Distributions Of Pelagic Sargassum In The Intra-Americas Sea And Atlantic Ocean, Mengqiu Wang

USF Tampa Graduate Theses and Dissertations

Pelagic Sargassum is one type of marine macroalgae that is known to be abundant in the Gulf of Mexico and Sargasso Sea. It is also known to serve as a critical habitat for many marine animals. In the past few years, large amounts of Sargassum have been reported in the Tropical Atlantic and Caribbean Sea (CS), causing significant environmental and economic problems. The goal of this study is to improve the understanding of Sargassum distributions, quantity, transport pathways, and bloom mechanisms in the CS and Tropic Atlantic through combining a variety of techniques including satellite remote sensing, field and laboratory …

Eleven Years Of Mountain Weather, Snow, Soil Moisture And Streamflow Data From The Rain–Snow Transition Zone – The Johnston Draw Catchment, Reynolds Creek Experimental Watershed And Critical Zone Observatory, Usa, James P. Mcnamara

Geosciences Faculty Publications and Presentations

Detailed hydrometeorological data from the rain-to-snow transition zone in mountain regions are limited. As the climate warms, the transition from rain to snow is moving to higher elevations, and these changes are altering the timing of downslope water delivery. To understand how these changes impact hydrological and biological processes in this climatologically sensitive region, detailed observations from the rain-to-snow transition zone are required. We present a complete hydrometeorological dataset for water years 2004 through 2014 for a watershed that spans the rain-to-snow transition zone (https://doi.org/10.15482/usda.adc/1402076). The Johnston Draw watershed (1.8km²), ranging from 1497 to 1869m in elevation, is …

Groundwater And Thermal Legacy Of A Large Paleolake In Taylor Valley, East Antarctica As Evidenced By Airborne Electromagnetic And Sedimentological Techniques, Krista Falcon Myers

LSU Master's Theses

During the Last Glacial Maximum, grounded ice in the Ross Sea extended into the otherwise ice-free McMurdo Dry Valleys, creating a series of large ice dammed paleolakes. Grounded ice within the mouth of Taylor Valley allowed for lake levels to reach elevations not possible at modern day and formed what is known as Glacial Lake Washburn (GLW). GLW extended from the eastern portion of Taylor Valley roughly 20 km west to a level ~300 m higher than modern day Lake Fryxell. The formation and existence of GLW has been debated, though previous studies correlate the timing of GLW with early …

Hydrothermal Water-Rock Reaction Modeling With Microbial Considerations: Rabbit Creek Area, Yellowstone National Park, Wy, Shanna Law

Graduate Theses & Non-Theses

Water-rock reactions at depth are the main control on aqueous hydrothermal chemistries of hot springs and other thermal features. Thermophilic microbes living in the hydrothermal system are a secondary control on aqueous hydrothermal chemistries and are expected to have increasing influence as spring temperatures decrease. The Rabbit Creek area of Yellowstone National Park (YNP) is an ideal case study for investigating the geologic and biologic controls on aqueous hydrothermal chemistries due to the proximity of the drill core Y-5 to geochemically diverse hydrothermal features (17.3⁰C to 92.2⁰C ± 0.1⁰C; field pH values 6.50 to 9.60 ± 0.05).

The modeling program …

Hyporheic Source And Sink Of Nitrous Oxide, W. Jeffery Reeder, Annika M. Quick, Tiffany B. Farrell, Shawn G. Benner, Kevin P. Feris, Alessandra Marzadri, Daniele Tonina

Geosciences Faculty Publications and Presentations

Nitrous oxide (N₂O) is a potent greenhouse gas with an estimated 10% of anthropogenic N₂O coming from the hyporheic zone of streams and rivers. However, difficulty in making accurate fine-scale field measurements has prevented detailed understanding of the processes of N₂O production and emission at the bedform and flowline scales. Using large-scale, replicated flume experiments that employed high-density chemical concentration measurements, we have been able to refine the current conceptualization of N₂O production, consumption, and emission from the hyporheic zone. We present a predictive model based on a Damköhler-type transformation (τ̃) in …

Isotopic And Geochemical Analysis Of Nitrate Contaminated Groundwater In Edgar, Nebraska, Nathan Roddy

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

High nitrate concentrations in the groundwater beneath Edgar, Nebraska have been measured for well over a decade, exceeding the EPA’s MCL of 10 mg-N/L. Investigating the isotopic signature of nitrate and groundwater have determined the likely source(s) of contamination. Apparent seasonal changes exists in nitrate concentration, isotope ratios, and geochemistry, suggesting that sources and flow paths change as a result of irrigation. Samples collected in December and May had very similar nitrate concentrations (average value of 13.7 mg-N/L) and isotopic ratios (δ¹⁵N 4.46‰ and δ¹⁸O-NO₃ 20.21‰), suggesting synthetic nitrate fertilizers are the major source of …

Assessment Of The Ponderosa Woodlands In Nebraska's Wildcat Hills: Implications For Juniperus Encroachment And Management, Allie Victoria Schiltmeyer

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

Ponderosa pine (Pinus ponderosa) is a dominant tree species across western North America. Its eastern distribution includes three populations in western Nebraska. This study assesses the distribution, structure and age of ponderosa pine woodlands in one of those regions, the Wildcat Hills. The Wildcat Hills have escaped severe wildfires seen in recent decades in other ponderosa pine regions. Nevertheless, the Wildcat Hills woodlands face multiple threats including climate change, wildfire, drought, pine beetles, and invasive species. Key to these threats is the stand structure of pine woodlands, which have increased in density across much of ponderosa pine’s range. …

Relationships Between Fluvial Ecosystems And The Iowan Erosion Surface, Lilian Heinzel, Chad E. Heinzel

Undergraduate Student Work

The streams and rivers of the Iowan Surface partially form the foundation of our local ecosystems, everything from providing drinking water to producing floods. The Black Hawk Creek, Cedar River, and Maquoketa River were studied in the months of June and July of 2018. The goal of the research was to understand the ecology of each water way, how life was sustained by these rivers and creek and how the surrounding landscape may have determined the features of the waterways. Datasheets were filled out describing the sites’ ecological and geologic makeup, and GIS Trimble units were used to chart the …

Contrasting Governance Learning Processes Of Climate-Leading And -Lagging Cities: Portland, Oregon, And Phoenix, Arizona, Usa, Jonathan H. Fink

Geology Faculty Publications and Presentations

The contrasting histories and political ecologies of two U.S. cities—Portland Oregon and Phoenix Arizona—shed light on their ability to learn from and influence the climate governance of their peers. Portland's populace, political leadership, and business sectors are motivated by environmental and social values, resulting in a collective sense of responsibility for fixing global problems like climate change. The city's pioneering land-use policies, green infrastructure, and multimodal transportation systems solidify its place at the climate action forefront. In contrast, libertarian Phoenix prioritizes real estate, efficient government, tourism, and protection of individual rights—the antithesis of Portland's altruism. However, because Phoenix's economic success …

Examining The Factors Shaping The Population Structure Of Thalassoma Bifasciatum In The Lemon Keys, Guna Yala, Panama, Nicole Stevens

Independent Study Project (ISP) Collection

Research question

What is the population structure of Thalassoma bifasciatum in the Lemon Keys, Guna Yala, Panama?

Research objective

To examine size class structure of Thalassoma bifasciatum and how its abundance and density vary in relation to factors such as substrate, species diversity and depth.

Advances In Amino Acid Analysis For Marine Related Matrices And Its Application To Coastal Shelf Settings In The Canadian Arctic, Rachel M. Mcmahon

OES Theses and Dissertations

Amino acids comprise up to 50% of organic matter in cellular material and are a major fraction of oceanic organic carbon. Amino acids are also considered highly labile during organic matter recycling, making them useful proxies for organic carbon cycling. Nevertheless, analysis of individual amino acids has been burdened by lengthy derivatization and complex analysis since the 1950s. In this thesis, I describe the modification of advanced analytical techniques, developed in the biomedical field, for analysis of marine matrices which allow the determination of at least 40 amino acids without the need for lengthy sample preparation and derivatization, twice the …

A Broad Spectrum Racemase In Pseudomonas Putida Kt2440 Plays A Key Role In Amino Acid Catabolism, Atanas D. Radkov, Luke A. Moe

Plant and Soil Sciences Faculty Publications

The broad-spectrum amino acid racemase (Alr) of Pseudomonas putida KT2440 preferentially interconverts the L- and D-stereoisomers of Lys and Arg. Despite conservation of broad-spectrum racemases among bacteria, little is known regarding their physiological role. Here we explore potential functional roles for Alr in P. putida KT2440. We demonstrate through cellular fractionation that Alr enzymatic activity is found in the periplasm, consistent with its putative periplasm targeting sequence. Specific activity of Alr is highest during exponential growth, and this activity corresponds with an increased accumulation of D-Lys in the growth medium. An alr gene knockout strain (Δalr) was generated …

New Insights On Secondary Minerals From Italian Sulfuric Acid Caves, Ilenia M. D'Angeli, Cristina Carbone, Maria Nagostinis, Mario Parise, Marco Vattano, Giuliana Madonia, Jo De Waele

International Journal of Speleology

Sulfuric acid minerals are important clues to identify the speleogenetic phases of hypogene caves. Italy hosts ~25% of the known worldwide sulfuric acid speleogenetic (SAS) systems, including the famous well-studied Frasassi, Monte Cucco, and Acquasanta Terme caves. Nevertheless, other underground environments have been analyzed, and interesting mineralogical assemblages were found associated with peculiar geomorphological features such as cupolas, replacement pockets, feeders, sulfuric notches, and sub-horizontal levels. In this paper, we focused on 15 cave systems located along the Apennine Chain, in Apulia, in Sicily, and in Sardinia, where copious SAS minerals were observed. Some of the studied systems (e.g., …

Climate And Plant Controls On Soil Organic Matter In Coastal Wetlands, Michael J. Osland, Christopher A. Gabler, James B. Grace, Richard H. Day, Meagan L. Mccoy, Jennie L. Mcleod, Andrew S. From, Nicholas M. Enwright, Laura C. Feher, Camille L. Stagg

School of Earth, Environmental, & Marine Sciences Faculty Publications

Coastal wetlands are among the most productive and carbon‐rich ecosystems on Earth. Long‐term carbon storage in coastal wetlands occurs primarily belowground as soil organic matter (SOM). In addition to serving as a carbon sink, SOM influences wetland ecosystem structure, function, and stability. To anticipate and mitigate the effects of climate change, there is a need to advance understanding of environmental controls on wetland SOM. Here, we investigated the influence of four soil formation factors: climate, biota, parent materials, and topography. Along the northern Gulf of Mexico, we collected wetland plant and soil data across elevation and zonation gradients within 10 …