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Community Ecology And Population Dynamics Of The Nearshore Marine Fauna In The Middle Atlantic Bight (Usa), Juan Carlos Levesque

Earth & Environmental Sciences Dissertations - Archive

Natural resources are among the most valuable commodities on earth. Some natural resources (air, land, and water) are essential for human survival and many often constitute a large percentage of local, regional, and national economies, such as marine resources. Worldwide, marine resources have shaped culture, society, and local, regional, and global economies. Oceanic environmental conditions influence, shape, and control the geographical range, spatial distribution, abundance, and size composition of marine fauna. Thus, marine communities are vulnerable to major changes in the environmental conditions and disturbance (short and long-term), but the response and severity depends on various biological or ecological factors, …

Sensitivity Of Oxygen Minimum Zones Due To Carbon Dioxide Radiative Forcing Using Cesm 1.2, Kristina K. Wolfe

Earth & Environmental Sciences Theses - Archive

Anthropogenic-induced climate change is occurring at an unprecedented rapid rate, compared to the geologic past. In this study, CO2 stabilization scenarios (1x, 2x, and 4x preindustrial atmospheric pCO2 levels) utilizing the Community Earth System Model (CESM) are carried out to assess the response of oxygen minimum zones to net primary production and vertical carbon fluxes in a changing climate. Compared to the 1x CO2 experiment, sea surface temperature (SST) rise in the 4x CO2 scenario, to 3 °C to 5 °C in the Pacific and Atlantic Ocean, between 30 °S and 60 °S. In contrast, the North Atlantic Ocean and …

Two Cretaceous Tales Of The Land And The Sea, Puloma Chakrabarty

Earth & Environmental Sciences Dissertations - Archive

The Cretaceous Period (145-66 Ma), with no magnetic reversal for ~79 Ma, is generally termed as the Cretaceous Normal Superchron or the Magnetic Quiet Zone. There is evidence of at least two major large scale, global volcanisms in this long period synchronous with mass extinctions, during the Late Cretaceous and at the end of the Cretaceous. This study focusses on the effect of these two global volcanisms on 1. The Ocean: Eagle Ford, South Texas at the beginning of the Late Cretaceous, 93.9 Ma, probably caused by Cretaceous mafic volcanism from the Ontong Java Plateau and/or Caribbean Large Igneous Province …

Leveraging Environmental Research And Observation Networks To Advance Soil Carbon Science, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

Soil organic matter (SOM) is a critical ecosystem variable regulated by interacting physical, chemical, and biological processes. Collaborative efforts to integrate perspectives, data, and models from interdisciplinary research and observation networks can significantly advance predictive understanding of SOM. We outline how integrating three networks—the Long‐Term Ecological Research with a focus on ecological dynamics, the Critical Zone Observatories with strengths in landscape/geologic context, and the National Ecological Observatory Network with standardized multiscale measurements—can advance SOM knowledge. This integration requires improved data dissemination and sharing, coordinated data collection activities, and enhanced collaboration between empiricists and modelers within and across networks.

Factors Affecting Willingness To Cultivate Switchgrass: Evidence From A Farmer Survey In Missouri, Pralhad Burli, Pankaj Lal, Bernabas Wolde, Shibu Jose, Sougata Bardhan

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Switchgrass is considered as one of the important feedstocks that can contribute towards the attainment of bioenergy goals set under the Renewable Fuels Standard. Yet, the commercial viability of switchgrass based bioenergy is a much debated topic owing to supply side challenges emanating from limited raw materials. It is therefore critical to understand the crucial role of the farmer by studying the willingness to cultivate switchgrass dedicated for bioenergy. To our knowledge, this is the first survey undertaken to assess the farmer preferences and participation in bioenergy markets after the new administration has assumed office, and provides some important insights. …

Incorporating Recent Geochemical And Isotopic Constraints In Age Dating The Waters Of Hot Springs National Park, Arkansas, Kristina Marie Raley

Graduate Theses and Dissertations

Mean water age for spring discharge in Hot Springs National Park was calculated as approximately 4,400 years by Bedinger et al (1978) using carbon-14. Their analysis indicated that the water was a mixture of a small portion of cold water that was less than twenty years old with a preponderance of hot water. However, this result includes some error due to Bedinger et al. using general isotopic values for soil dissolved inorganic carbon and mineral carbon instead of obtaining actual values from the study area. A more accurate age calculation for the springs has been made possible by additional geological …

Using Cover Crops To Recycle Nutrients In An Arkansas No-Till Corn System, Kelsey Lynn Hoegenauer

Graduate Theses and Dissertations

Cover crops can provide many benefits to cropping systems including erosion control, weed suppression, and increased soil organic matter. Regardless of the intended goal for using cover crops, the changes to the nutrient flux in a cropping system caused by cover crops retaining and recycling nutrients needs to be considered in order to maximize the productivity of the following commodity crops. This research encompassed complementary greenhouse, field, and laboratory experiments to evaluate nutrient uptake and release by tillage radish (Raphanus sativus) and cereal rye (Secale cereale) cover crops, as well as the subsequent early-season recovery of recycled nutrients by the …

The Niobrara National Scenic River: Exploring Co-Management Through A Case Study Of The Niobrara Council, Melissa M. Mosier

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

In recent decades, government staff and local citizens have increasingly employed cooperative schemes of natural resource management, in lieu of more conventional, top-down approaches of addressing user conflicts as they relate to water resources. The focus of this project was on the Niobrara Council, a partnership of local, state, and federal representatives charged with cooperatively managing the reach of the Niobrara River that was federally designated under the Wild and Scenic Rivers Act in 1991. The project's purpose was to explore the cooperative framework of the Council, using the methodology outlined by Carlsson and Berkes (2005). This methodology involved investigating …

Population Dynamics Of The Freshwater Mussel Lampsilis Cardium Reintroduced In Nebraska, Lindsay M. Ohlman

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

The global decline of native freshwater mussels has accelerated conservation projects that preserve and restore populations, but the complex life histories among species challenges biologists in determining the most effective management strategies. This study details the conservation of plain pocketbook, a Tier I threatened mussel species in Nebraska that was artificially propagated and reintroduced into 13 sites from autumn 2016 to summer 2017. The objectives of this study were: 1) determine how handling influences mussels, and 2) evaluate mussel growth and survival following introductions.

We conducted a laboratory experiment with age-2 plain pocketbook to assess the effects of handling on …

Remote Sensing Time-Series Analysis, Machine Learning, And K-Means Clustering Improves Dryland Vegetation And Biological Soil Crust Classification, Joshua Enterkine

Boise State University Theses and Dissertations

Dryland and semi-arid vegetation communities, although appearing to the casual observer as relatively simplistic and homogeneous, are in fact the opposite. Upon further inspection, semi-arid vegetation is highly complex and heterogeneous at almost any scale. The same holds true for biological soil crust. Growing concern about global changes in climate, nutrient cycles, and land use have required increasing scrutiny of our understanding of these communities and all of their constituents, as we seek to improve forecasting models and inform land management decisions. This thesis aims to provide insight to the paradigm of how we create and interpret vegetation classifications in …

A Bayesian Framework For Estimating Seismic Wave Arrival Time, Hua Zhong

Graduate Theses and Dissertations

Because earthquakes have a large impact on human society, statistical methods for better studying earthquakes are required. One characteristic of earthquakes is the arrival time of seismic waves at a seismic signal sensor. Once we can estimate the earthquake arrival time accurately, the earthquake location can be triangulated, and assistance can be sent to that area correctly. This study presents a Bayesian framework to predict the arrival time of seismic waves with associated uncertainty. We use a change point framework to model the different conditions before and after the seismic wave arrives. To evaluate the performance of the model, we …

Assessing Minimal-Input Restoration Strategies For Desert Soil And Vegetation Restoration, Audrey Jean Rader

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mojave and Sonoran Deserts have been negatively impacted by anthropogenic disturbances. Considering that these ecosystems may recover on millennial timescales, research has shown that restoration techniques can be fairly successful in initiating long-term recovery processes in these sensitive environments. However, uncertainty remains as to which techniques are effective in different circumstances, such as in different climates or across different soil properties, and which techniques may best avoid unintended consequences, such as facilitating non-native plants. To reduce fugitive dust as a human health hazard, increase soil stability, and enhance wildlife habitat, further work is necessary to develop restoration techniques for …

Assessing Simulated Transmissivity In Numerical Flow Models Of Complex Hydrogeology, Afan Tarar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Accurately extracting a meaningful transmissivity, a target value within one order of magnitude of field estimates, in numerical models poses a significant challenge when modeling complex groundwater systems. Aquifer transmissivity is directly proportional to the aquifer thickness and the estimated aquifer hydraulic conductivity. In complex geologic conditions (especially in fractured systems) with multiple heterogeneous and anisotropic hydrogeologic units, transmissivity can vary over several orders of magnitude.

To extract a meaningful value of transmissivity from a numerical model, a simple five-layer MODFLOW model was constructed. Each layer in the model was assigned a fixed hydraulic conductivity and thickness. The model simulates …

Rating Curve Development For The Upper James Fork, Lower James Fork And Hinkle Jones Creek In The Upper Poteau River Watershed In Arkansas, Meagan O'Hare

Biological and Agricultural Engineering Undergraduate Honors Theses

Stream discharge is necessary to estimate loads and calibrate and validate watershed models. Access to long-term water quality data and discharge measurements allows for modeling of water quality changes across a watershed over time. However, discharge monitoring stations are often expensive to install and maintain, particularly in small rivers. A more cost-effective method for monitoring streamflow has been implemented in the Upper Poteau River Watershed (UPRW) in Arkansas. This method consists of an SonTek acoustic doppler instrument for measuring storm stream flow, with is combined with manual baseflow discharge measurements. The combined stormflow and baseflow measurements are combined with a …

Effects Of Elevated Temperature On Gonadal Functions, Cellular Apoptosis, And Oxidative Stress In Atlantic Sea Urchin (Arbacia Punctulata), Jackson B. Johnstone

Theses and Dissertations

Increasing surface sea water temperatures effect on growth, reproduction and development in marine organisms. Sea urchins are excellent indicator species and ideal model organisms to focus on. In this study, I tested the effect of higher temperatures on reproductive functions, heat shock protein (HSP, a chaperone protein produced by cells in response to heat stress) and nitrotyrosine protein (NTP, an indicator of reactive nitrogen species, RNS) expressions, cellular apoptosis, and ceolomic fluid (CF, a body fluid which regulates important physiological processes) conditions in Atlantic sea urchin at three different temperatures. Ten sea urchins were placed in each of six aquariums …

A Snapshot Of The Age, Growth, And Reproductive Status Of Gray Triggerfish (Balistes Capriscus, Gmelin 1789) On Three Artificial Reefs In The Northwest Gulf Of Mexico, Adam M. Lee

Theses and Dissertations

Age, growth, and reproductive status of gray triggerfish (Balistes capriscus) were identified from 2015-2016 on artificial reefs in the northwest Gulf of Mexico. Individuals ranged from 232-432 mm fork length with and a mean fork length of 319 mm. Individuals from age 0.2 to 5.2 yrs were observed with a weight to length relationship of Wg = 1.1 x -104 x FL2.7 (r2 = 0.94, n = 112), where FL = fork length (mm) and Wg = weight (g). A von Bertalanffy growth equation of Lt = 326(1 - e - 0.9 (t + 1.71)) was calculated irrespective …

Effects Of Global Warming On Gonadal Functions, Cellular Apoptosis, And Oxidative Stress In The American Oyster, Sarah B. Nash

Theses and Dissertations

Global warming due to climate change is predicted to intensify the heat stress in marine and coastal organisms, affecting their development, growth and reproductive functions. In this study. I analyzed gonadal development, heat shock protein 70 (HSP70), nitrotyrosine protein (NTP), dinitrophenyl (DNP) expressions, cellular apoptosis, and coelomic fluid (CF) conditions in American oyster. Oysters were placed in six aquariums and exposed to control (24°C), medium (28°C), and high (32°C) temperatures for one week. Higher temperature significantly decreased the number of eggs and sperm. CF protein concentrations also declined compared to control. In contrast, CF pH and HSP70 expression in gonad …

Ecometric Estimation Of Present And Past Climate Of North America Using Crown Heights Of Rodents And Lagomorphs: With Application To The Middle Miocene Climatic Optimum, Julia Schap

Electronic Theses and Dissertations

Continental scale studies on ungulate crown heights in relation to climate and habitat changes have revealed a correlation between increasing hypsodonty and a shift to more arid environments. Small mammals have been shown to adapt to changing habitats millions of years earlier than larger mammals. In this study I examined fossil localities throughout the last 37 Ma across North America. Diversity of rodents and lagomorphs were analyzed through this time period, with examination of community structure characterized by relative percentages of taxa with different crown heights. Overall, a decrease in precipitation and temperature was found across North America from 37 …

Paleoecology And Land-Use Of Quaternary Megafauna From Saltville, Virginia, Emily Simpson

Electronic Theses and Dissertations

Land-use, feeding habits, and response to seasonality by Quaternary megaherbivores in Saltville, Virginia, is poorly understood. Stable isotope analyses of serially sampled Bootherium and Equus enamel from Saltville were used to explore seasonally calibrated (δ¹⁸O) patterns in megaherbivore diet (δ¹³C) and land-use (⁸⁷Sr/⁸⁶Sr). Overall, this dataset suggests an open forest with relatively constant temperatures year round that were similar to modern conditions. Neither Bootherium or Equus individuals spent a significant amount of time at higher elevations in the nearby Blue Ridge geologic province. These analyses provide a unique perspective on long-term response …

Detecting Coastal Marsh Change From Aerial Imagery Using Spectral And Textural Methods: Pascagoula River Estuary, Mississippi, 1955-2014, Margaret Claire Bell Waldron

Master's Theses

As sea level rise accelerates, coastal marsh ecosystems are increasingly vulnerable. Vertical accretion rates must exceed or keep pace with rates of sea level rise to prevent transition to open water or inland migration of marsh vegetation. While some marsh systems along the northern Gulf of Mexico coast have remained stable, others, e.g., the marshes of the Louisiana Gulf Coast, have experienced high rates of conversion to open water. This study examined the historical extent of intertidal marsh at the mouth of the Pascagoula River in Jackson County, Mississippi to determine whether marsh extent changed during the period 1955-2014 and …

Comparative, Lithology-Based Biogeography Of Phreatophytic And Non-Phreatophytic Matrices Along A North-South Gradient Of The South Texas Sand Sheet, Christopher Joaquin Munoz

Theses and Dissertations

A 70km-long, N-S stratigraphic cross-section spanning the entirety of the South Texas Sand Sheet (STSS) has been rendered along Texas Interstate 69C. The cross-section indicates localized zones of substantial STSS thickness (>4m) as well as zones where the underlying Goliad Formation is either exposed or just below the surface (<0.5m). Spatial patterns of both phreatophytic and non-phreatophytic vegetation assemblages were analyzed by means of remote sensing and in situ herbaceous species evaluations. Biogeographic patterns were comprised of three vegetation matrices: P. glandulosa-dominated, Q. virginiana-dominated and a matrix of herbaceous plants. The geographic distribution of vegetation assemblages corresponded to specific lithological parameters and features. Namely, Q. virginiana concentration exhibited a positive linear relationship with the lithological parameter of STSS thickness (P =2.122x10-11) (α = 0.05). P. glandulosa/V. farnesiana …

The Multifactorial Nature Of Beak And Skull Shape Evolution In Parrots And Cockatoos (Psittaciformes), Jen A. Bright, Jesús Marugán-Lobón, Emily J. Rayfield, Samuel N. Cobb

School of Geosciences Faculty and Staff Publications

Background: The Psittaciformes (parrots and cockatoos) are characterised by their large beaks, and are renowned for their ability to produce high bite forces. These birds also possess a suite of modifications to their cranial architecture interpreted to be adaptations for feeding on mechanically resistant foods, yet the relationship between cranial morphology and diet has never been explicitly tested. Here, we provide a three-dimensional geometric morphometric analysis of the developmental and biomechanical factors that may be influencing the evolution of psittaciformes’ distinctive cranial morphologies.

Results: Contrary to our own predictions, we find that dietary preferences for more- or less- mechanically resistant …

The Evaluation Of Low-Use-Rate Zinc Fertilization Strategies On Seedling Canopy Coverage, Zn Concentration, Biomass, And Grain Yield, Maxwell David Coffin

Graduate Theses and Dissertations

Zinc (Zn) is the most common micronutrient deficiency in flooded rice (Oryza sativa L.). Some new Zn fertilization methods have been advertised, but have limited research supporting their efficacy. This study mainly compared the effect of Zn-seed treatment rate in combination with other low-use-rate Zn-fertilization methods to the standard of 11 kg Zn ha-1 as ZnSO4 on rice early-season canopy cover, tissue-Zn concentration, and grain yield. A secondary objective evaluated an alternative method (to seed treatment with ZnO) of enhancing seed-Zn concentration using post-heading foliar-Zn application on seedling tissue-Zn concentration and grain yield. For the main objective, rice seed was …

Landuse And Soil Property Effects On Infiltration And Soil Aggregate Stability In The Lower Mississippi River Valley, Rebecca Lynn Anderson

Graduate Theses and Dissertations

Following European settlement of the Lower Mississippi River Valley (LMRV), agricultural expansion and unsustainable, agriculturally related practices have caused groundwater depletion, soil erosion, and surface water contamination by eroded sediments and sediment-bound nutrients to become major environmental threats to the region. The objective of this study was to evaluate the effects of common landuses [i.e., native prairie, deciduous forest, coniferous forest, Conservation Reserve Program (CRP) grassland, and conventional-tillage (CT) and no-tillage (NT) agriculture] on surface water infiltration and aggregate-stability-related properties [i.e., water-stable macroaggregate (WSA) size distribution, total water-stable macroaggregate (TWSA) concentration, and mean weight diameter (MWD)]. The overall infiltration rate …

Reduced Disposal Area Performance Utilizing Secondary-Treated Effluent In Profile-Limiting Soils, David A. Meints

Graduate Theses and Dissertations

Onsite wastewater systems dispose of primary treated effluent by utilizing the soil for final recycling and renovation of wastewater into the environment. Soil and site limitations have become a challenge to design a wastewater system and dispose of onsite wastewater using a conventional pipe and gravel design. Using secondary-treated effluent from an advanced treatment unit applied to a reduced disposal area offers an additional alternative when developing an onsite wastewater system. The objective of this study was to determine the feasibility of hydraulically loading limiting soils with secondary-treated effluent in a reduced disposal area. A reduced disposal area was constructed …

Mountain-Block Recharge To The Cache Valley Principal Aquifer And Geochemical Controls On Groundwater Movement In Alpine Karst, Skyler J. Sorsby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Groundwater is documented to flow through solution-widened fractures and bedding planes in limestone and dolostone units in low-relief topography. This enhancement, or karstification, is much harder to study in alpine environments like the Bear River Range of northern Utah. This is problematic, due to the fact that the Bear River Range karst aquifer system supplies the City of Logan with a large quantity of water at Dewitt Spring. Furthermore, the karst aquifer sustains the Logan River for much of the year, and may allow groundwater to flow directly in the subsurface to the Cache Valley principal aquifer system.

Flow measurements …

Ediacaran Depositional Age And Subsequent Fluid-Rock Interactions In The Mutual And Browns Hole Formations Of Northern Utah, Ashley W. Provow

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Constraining the depositional age of Neoproterozoic stratigraphy in western North America has implications for correlating global glaciation and tectonic events. The depositional ages of the Neoproterozoic Mutual and Browns Hole formations of northern Utah are controlled by two conflicting datapoints. However, new U-Pb geochronological data from 95 detrital apatite grains refines the maximum depositional age of the volcanic member of the Browns Hole Formation to 613 ± 12 Ma (2σ). This places new restrictions on the time available for the deposition of underlying units. Due to debate regarding the age models for underlying stratigraphy, two scenarios for sediment accumulation rates …

Modelling Water Fluxes In Plants: From Tissues To Biosphere, Maurizio Mencuccini, Stefano Manzoni, Bradley O. Christoffersen

School of Earth, Environmental, & Marine Sciences Faculty Publications

Contents Summary 1207 I. Introduction 1207 II. A brief history of modelling plant water fluxes 1208 III. Main components of plant water transport models 1208 IV. Stand-scale water fluxes and coupling to climate and soil 1213 V. Water fluxes in terrestrial biosphere models and feedbacks to community dynamics 1215 VI. Outstanding challenges in modelling water fluxes in the soil-plant-atmosphere continuum 1217 Acknowledgements 1218 References 1218 SUMMARY: Models of plant water fluxes have evolved from studies focussed on understanding the detailed structure and functioning of specific components of the soil-plant-atmosphere (SPA) continuum to architectures often incorporated inside eco-hydrological and terrestrial biosphere …

Comment On Rojas-Bracho And Colleagues (2019): Unsubstantiated Claims Can Lead To Tragic Conservation Outcomes, Karl W. Flessa, Luis Calderon-Aguilera, Carlos E. Cintra-Buenrostro, David L. Dettman, Gregory P. Dietl, David H. Goodwin, David K. Jacobs, Michal Kowalewski, Steven M. Nelson, Kirsten Rowell, Bernard R. Schone, Jansen A. Smith, Francisco Zamora-Arroyo

School of Earth, Environmental, & Marine Sciences Faculty Publications

The vaquita’s decline is a tragic story indeed. However, the lack of action to prevent the extinction of this species is not due to unsubstantiated claims and scientific uncertainty.

The Sedimentology Of Cay Sal Bank - An Incipiently Drowned Carbonate Platform, Luis Ramirez

HCNSO Student Theses and Dissertations

Sediment on Cay Sal Bank (CSB) is characterized by its coarse-grain size, poor sorting, predominance of skeletal fragments, and relatively depleted d¹⁸O isotope values. CSB is an incipiently drowned platform in close proximity to the Great Bahama Bank (GBB), a carbonate platform which is not incipiently drowned and characterized by fine-grained, non-skeletal sediment. The GBB has locally well-developed oolitic grainstone facies and coral reef margins, which are both lacking on CSB. Platform-top water depths on the GBB are typically 10 m or less, but CSB depth ranges between 7 and 30 m. CSB is devoid of mud, whereas …