Digital Commons Network^™

Defining, Measuring, And Applying Soil Quality: An Unresolved Debate, Salvador Ramirez Ii

Doctor of Plant Health Program: Dissertations and Student Research

Paradigm shifts occur periodically in the sciences. Proposed paradigm shifts offer opportunities to reexamine extant paradigms and evaluate new ones. Soil science experienced a controversy resembling a proposed paradigm shift in the late 1990s and early 2000s when it grappled with the idea of soil quality (SQ). The most contentious points in the SQ debates were (1) the word “quality” itself and designing a functional definition, (2) identifying appropriate soil quality indicators, (3) the integration of soil quality indicators, and (4) the interpretation of soil quality indicators. The latter three disagreements were rooted in the established, fundamental, soil science paradigm. …

Irrigation Forbearance In The Middle Rio Grande: Using Remote Sensing To Improve Investments, Trevor Birt

Water Resources Professional Project Reports

In extremely dry years when there is a high premium on surface water, irrigation forbearance agreements help water managers maintain riparian health, fish populations, and ensure water delivery to downstream users. In order for these programs to maximize their effectiveness and limit their impact on agricultural communities, water managers should seek the highest return on investment - or the highest amount of water per acre entered into forbearance. This may be accomplished by assessing the water requirements of fields and then grouping by conveyance lateral, to target the highest among them as good forbearance participants. Unfortunately, irrigation measurement in the …

Nitrate Contaminant Tracing In Surface And Groundwater In The Great Miami River Watershed: Environmental Isotope Approach, Rachel Kristine Buzeta

Honors Theses

The global population has increased exponentially causing several challenges surrounding sustainability, including greater food production needs. To meet these demands and boost agricultural productivity, more efficient practices and fertilizers are used. Synthetic fertilizers and other nutrient sources have resulted in water quality degradation and pollution. Much of the Great Miami River Watershed’s streams and aquifers in southwestern Ohio are affected by nitrate contaminants originating from anthropogenic sources including synthetic and organic fertilizer used for agriculture, human wastes (domestic, industrial, and municipal wastes), and urbanization. High nitrate concentrations cause ecological disturbances across all trophic levels. Nitrate levels greater than 10 mg/L …

Submarine Groundwater Discharge In The Southern Chesapeake Bay: Constraints From Numerical Models, Charles Louis Carlson

OES Theses and Dissertations

Terrestrial and oceanic forces drive fluid flow within the coastal zone to produce submarine groundwater discharge (SGD). Groundwater flowing from the seabed serves as a significant pathway for contaminants and nutrients, producing an active biogeochemical reaction zone. In order to quantify the importance of SGD in geochemical and hydrologic budgets for the lower Chesapeake Bay, three coastal Virginia transects (southern Eastern Shore, Lafayette River, and Ocean View beach) with different topographic gradients were modeled using similar boundary conditions and consistent treatment of hydrogeologic layers. A sensitivity study was performed on the variables of recharge rate, seawater density, and hydraulic permeability. …

Population Fragmentation Leads To Morpho-Functional Variation In British Red Squirrels (Sciurus Vulgaris), Philip G. Cox, Philip J.R. Morris, Andrew C. Kitchener

School of Geosciences Faculty and Staff Publications

It is well-known that population fragmentation and isolation can lead to rapid morphological and functional divergence, with the effect being particularly well-documented in rodents. Here, we investigated whether such a phenomenon could be identified in the Eurasian red squirrel (Sciurus vulgaris), which was once widespread across the majority of Great Britain, but suffered a severe population decline across the 20^th century, leaving a highly fragmented distribution. The aim was to test for morphological and biomechanical variation of the mandible between the remaining British red squirrel populations. Linear and geometric morphometric methods were used to analyse shape in …

Suspended Sediment Transport Revealed By Patterns In Turbidity And Electrical Conductivity Curves In Three Cave Systems In Missouri, Usa., Caroline M. Mierzejewski

LSU Master's Theses

In cave streams, the movement of sediment as suspended and bed loads are linked to the occurrence of precipitation events on the surface. During precipitation events, the discharge of the streams in the basin increases. As those surface streams flow into cave streams via sinkholes or fissures, the discharge in cave streams increase. In addition to changes in discharge, the response of the surface and cave streams to precipitation include changes in turbidity and electrical conductivity of the stream water.

Changes in turbidity (Tu), electrical conductivity (EC), and discharge (Q) of water in the cave stream can be used to …

Using Multi-Indices Approach To Quantify Mangrove Changes Over The Western Arabian Gulf Along Saudi Arabia Coast, Wenzhao Li, Hesham El-Askary, Mohamed A. Qurban, Jingjing Li, K. P. Manikandan, Thomas Piechota

Mathematics, Physics, and Computer Science Faculty Articles and Research

Mangroves habitat present an important resource for large coastal communities benefiting from activities such as fisheries, forest products and clean water as well as protection against coastal erosion and climate related extreme events. Yet they are increasingly threatened by natural pressure and anthropogenic activities. We observed an inaccurate distribution of mangroves over the Western Arabian Gulf (WAG) which is a vital habitat and resource for the local ecosystem, according to the United Stated Geological Survey (USGS) mangrove database through spectral analysis. Change detection analysis is conducted on mangrove forests along the Saudi Arabian coast of the WAG for the years …

Guano-Related Phosphate-Rich Minerals In European Caves, Philippe Audra, Jo De Waele, Ilham Bentaleb, Alica Chroňáková, Václav Krištůfek, Ilenia M. D'Angeli, Cristina Carbone, Giuliana Madonia, Marco Vattano, Giovanna Scopelliti, Didier Cailhol, Nathalie Vanara, Marjan Temovski, Jean-Yves Bigot, Jean-Claude Nobécourt, Ermanno Galli, Fernando Rull, Aurelio Sanz-Arranz

International Journal of Speleology

Guano is a typical deposit found in caves derived from the excretions of bats and in minor cases of birds. These organic deposits decompose and form a series of acid fluids and gases that can interact with the minerals, sediments, and rocks present in the cave. Over sixty phosphates are known and described from caves, but guano decay also often leads to the formation of nitrates and sulfates. In this study twenty-two European caves were investigated for their guano-related secondary minerals. Using various analytical techniques, seventeen phosphates, along with one sulfate (gypsum), were recognized as secondary products of guano decay. …

Taking On Water: Winters, Necessity And The Riparian East, Jacqueline Goodrum

William & Mary Environmental Law and Policy Review

In the eastern United States, a natural abundance of water has historically satisfied regional water needs. However, rapid population growth and expansive development, as well as changing climate conditions, threaten to deplete and diminish regional water resources. Riparianism, the reigning water rights regime in the American East, is insufficient to address concerns arising from these emerging forces because it assumes sufficient water will be available for all users. Recent interstate disputes, such as Virginia v. Maryland and Florida v. Georgia, highlight a new hydrological reality characterized by not only increased consumption of eastern water resources, but also by increased …

The Accelerating Influence Of Humans On Mammalian Macroecological Patterns Over The Late Quaternary, Felisa A. Smith, Rosemary E. Elliott Smith, S. Kathleen Lyons, Jonathan L. Payne, Amelia Villaseñor

School of Biological Sciences: Faculty Publications

The transition of hominins to a largely meat-based diet ~1.8 million years ago led to the exploitation of other mammals for food and resources. As hominins, particularly archaic and modern humans, became increasingly abundant and dispersed across the globe, a temporally and spatially transgressive extinction of large-bodied mammals followed; the degree of selectivity was unprecedented in the Cenozoic fossil record. Today, most remaining large-bodied mammal species are confined to Africa, where they coevolved with hominins. Here, using a comprehensive global dataset of mammal distribution, life history and ecology, we examine the consequences of “body size downgrading” of mammals over the …

Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust And Local Anthropogenic Sources, Michael Max Goodman

Theses and Dissertations

Dust originating from dry lakes contributes harmful and toxic elements to downwind urban areas and mountain snowpack that is compounded by local contaminant inputs from anthropogenic sources. To evaluate dust contributions to an urban area from regional playas, we sampled playa dust sources, urban dust deposition, and snow dust deposition in central Utah, USA. Samples were analyzed for grain size, mineralogy, and chemistry. Bulk mineralogy between playa, urban, and snow dust samples was similar, with silicate, carbonate, and evaporite minerals. Grain size distribution between fine playa, urban, and snow dust particles was also similar. Elements found at high concentrations in …

A New Direction For Salinity Management In Western Australia: A Consultative Review, Ghd

Natural resources commissioned reports

In May 2018, the Office of the Auditor General (OAG) published an audit into the management of salinity and recommended that the Department of Primary Industries and Regional Development (DPIRD), in consultation with the Department of Biodiversity, Conservation and Attractions (DBCA) and the Department of Water and Environmental Regulation (DWER), set a strategic direction for salinity management for WA and improve monitoring, cooperation, coordination, promotion of soil conservation, and compliance of salinity impacts and its management.

The OAG’s audit focused on two questions:

1. Do agencies know the extent and impact of dryland salinity in the South West agricultural regions?
2. Are …

Mechanical Significance Of Morphological Variation In Diprotodont Incisors, Philip J.R. Morris, Philip G. Cox, Samuel N. Cobb

School of Geosciences Faculty and Staff Publications

All rodents possess a single pair of enlarged incisors that grow throughout life. This condition (diprotodonty) is characteristic of Rodentia, but is also found in other mammals such as lagomorphs, hyraxes, the aye-aye and common wombat. This study surveyed lower incisor morphology across extant diprotodonts to examine shape variation within and between rodents and other diprotodonts, and to determine if tooth shape varies in a manner predictable from mechanics. Six linear and area variables were recorded from microCT scans of the mandibles of 33 diprotodont mammals. The curvature of the rodent lower incisors, as measured by the proportion of a …

Nebraska Statewide Groundwater-Level Monitoring Report 2018, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Michele M. Waszgis, Sue Olafsen Lackey, Robert Matthew Joeckel

Conservation and Survey Division: Faculty and Staff Publications

The term “groundwater” has come to be all but synonymous with Nebraska. Nearly three-quarters of the total volume of the High Plains Aquifer lies beneath the State. Groundwater maintains our streams, our ecosystems, our people, and our vitally important agricultural economy. Nebraska’s total groundwater resource is vast, yet it is also vulnerable to natural and anthropogenic changes, necessitating a long-term commitment to wise management through informed decision making. Monitoring, studying, and reporting form the essential basis for such management and, ultimately, for meeting the myriad challenges presented by change.

The personnel of the Conservation and Survey Division (CSD) are pleased …

Seasonal Origins Of Soil Water Used By Trees, Scott T. Allen, James W. Kirchner, Sabine Braun, Rolf T. W. Siegwolf, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Rain recharges soil water storages and either percolates downward into aquifers and streams or is returned to the atmosphere through evapotranspiration. Although it is commonly assumed that summer rainfall recharges plant-available water during the growing season, the seasonal origins of water used by plants have not been systematically explored. We characterize the seasonal origins of waters in soils and trees by comparing their midsummer isotopic signatures (δ2H) to seasonal isotopic cycles in precipitation, using a new seasonal origin index. Across 182 Swiss forest sites, xylem water isotopic signatures show that summer rain was not the predominant water source …

High-Resolution Record Reveals Climate-Driven Environmental And Sedimentary Changes In An Active Rift, Lisa C. Mcneill, Donna J. Shillington, Gareth D. O. Carter, Jeremy D. Everest, Robert L. Gawthorpe, Clint Miller, Marcie P. Phillips, Richard E. Ll. Collier, Aleksandra Cvetkoska, Gino De Gelder, Paula Diz, Mai-Linh Doan, Mary Ford, Maria Geraga, Jack Gillespie, Romain Hemelsdael, Emilio Herrero-Bervera, Mohammad Ismaiel, Liliane Janikian, Katerina Kouli, Erwan Le Ber, Shunli Li, Marco Maffione, Carol Mahoney, Malka L. Machlus, Georgios Michas, Casey W. Nixon, Sabire Asli Oflaz, Abah P. Omale, Kostas Panagiotopoulos, Sofia Pechlivanidou, Simone Sauer, Joana Seguin, Spyros Sergiou, Natalia V. Zakharova, Sophie Green

Publications and Research

Young rifts are shaped by combined tectonic and surface processes and climate, yet few records exist to evaluate the interplay of these processes over an extended period of early rift-basin development. Here, we present the longest and highest resolution record of sediment flux and paleoenvinronmental changes when a young rift connects to the global concerns. New results from International Ocean Discovery Program (IODP) Expedition 381 in the Corinth Rift shows 10s-100s of kyr cyclic variations in basin paleoenvironment as eustatic sea level fluctuated with respect to sills bounding this semi-isolated basin, and reveal substantial corresponding changes in the volume and …

Limits To The World’S Green Water Resources For Food, Feed, Fiber, Timber, And Bioenergy, Joep F. Schyns, Arjen Y. Hoekstra, Martijn J. Booij, Rick J. Hogeboom, Mesfin Mekonnen

Daugherty Water for Food Global Institute: Faculty Publications

Green water––rainfall over land that eventually flows back to the atmosphere as evapotranspiration––is the main source of water to produce food, feed, fiber, timber, and bioenergy. To understand how freshwater scarcity constrains production of these goods, we need to consider limits to the green water footprint (WFg), the green water flow allocated to human society. However, research traditionally focuses on scarcity of blue water––groundwater and surface water. Here we expand the debate on water scarcity by considering green water scarcity (WSg). At 5 × 5 arc-minute spatial resolution, we quantify WFg and the maximum sustainable level to this footprint (WFg,m), …

Soil Macroinvertebrate Presence Alters Microbial Community Composition And Activity In The Rhizosphere, Natalie Bray, Jenny Kao-Kniffin, Serita D. Frey, Timothy Fahey, Kyle Wickings

Faculty Publications

Soil Macroinvertebrate Presence Alters Microbial Community Composition and Activity in the Rhizosphere

How Good Is Our Kentucky Haylage? A Summary Of 2017-18 Farm Results, Jimmy C. Henning, Jeff Lehmkuhler, Levi Berg, April Wilhoit, Corinne Belton, Tommy R. Yankey

Kentucky Alfalfa and Stored Forage Conference

The ability to harvest moist forage as hay gives Kentucky producers many advantages, including timely harvest, higher forage quality, and less weathering loss over hay systems. The baleage system allows producers to utilize commonly available forage equipment (mowers, rakes, balers) rather than requiring choppers and silo structures or bags. Making high quality baleage requires timely access to bale wrappers.

Genetic Loci Associated With Salt Tolerance In Advanced Breeding Populations Of Tetraploid Alfalfa Using Genome-Wide Association Studies, Xiang-Ping Liu, Charles Hawkins, Michael D. Peel, Long-Xi Yu

Plants, Soils, and Climate Faculty Publications

Many agricultural lands in the western United States consist of soil with high concentrations of salt, which is detrimental to alfalfa (Medicago sativa L.) growth and production, especially in the region where water resource is limited. Developing alfalfa varieties with salt tolerance is imperative for sustainable production under increasing soil salinity. In the present study, we used advanced alfalfa breeding populations and evaluated five traits related to salt tolerance including biomass dry weight (DW) and fresh weight (FW), plant height (PH), leaf relative water content (RWC), and stomatal conductance (SC) under control and salt stress. Stress susceptibility index (SSI) …

Insights Into Paleoenvironmental Conditions, Relative Sea-Level, And Carbonate Reservoir Quality Using Ichnology: Middle–Upper Miocene Slope Deposits, Great Bahama Bank, Ryan M. Mustacato

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

Detailed ichnological and petrographic analyses were conducted on two biostratigraphically-constrained intervals (11.9-11.3 Ma and 10.7-9.4 Ma) from the Middle-Upper Miocene stratigraphy of the Great Bahama Bank’s leeward margin to assess spatiotemporal trends in paleoenvironmental conditions and reservoir properties in carbonate slope deposits. Six ichnofacies, varied in expression, are documented: the Skolithos Ichnofacies (distal and impoverished expressions) the Cruziana Ichnofacies (proximal, archetypal, distal and impoverished expressions), the Zoophycos Ichnofacies, the Nereites Ichnofacies, the Glossifungites Ichnofacies, and the Trypanites Ichnofacies. An analysis of spatiotemporal ichnofacies trends reveals two distinct responses of the benthic community to significant environmental perturbations on the slope. An …

Hunter And Angler Motivations, Preferences, And Barriers To Waterfowl Hunting In The Central United States, Matthew P. Hinrichs

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

Since the mid-1980s, there has been a decrease in individuals participating in waterfowl hunting in the United States. The decline in participation has over-arching consequences for state and federal wildlife agencies in their ability to fund and manage habitat and waterfowl populations. There is a fundamental need to understand why individuals participate in waterfowl hunting and what barriers there are to participating in waterfowl hunting. An online survey was conducted in the summer and fall of 2018 asking waterfowl hunters, anglers, big game hunters, combination users (i.e., hunters that have multiple hunting and fishing permits), and small game hunters about …

Molecular Cloning And Characterization Of Two Arnt (Arnt-1 And Arnt-2) Genes In Atlantic Croaker And Their Expression During Coexposure To Hypoxia And Pcb77, Md. Saydur Rahman, Peter Thomas

School of Earth, Environmental, & Marine Sciences Faculty Publications

Aryl hydrocarbon receptor nuclear translocator (ARNT) is an important transcriptions factor that binds/coactivates drug-metabolizing genes in vertebrates. In this study, we report the cloning and characterization of two ARNT (ARNT-1 and ARNT-2) genes and their mRNA and protein expression in liver tissues of Atlantic croaker after co-exposure to hypoxia and 3,3',4,4'-tetrachlorobiphenyl (PCB77). The full-length croaker ARNT-1 and ARNT-2 genes encode proteins of 537 and 530 amino acids, respectively, and are highly homologous to ARNT-1 and ARNT-2 genes of other vertebrates. ARNT mRNAs are ubiquitously expressed in all tissues. Hypoxia (dissolved oxygen: 1.7 mg/L) exposure (1-4 weeks) did not affect hepatic …

Comparison Of Microbial Communities In The Sediments And Water Columns Of Frozen Cryoconite Holes In The Mcmurdo Dry Valleys, Antarctica, Pacifica Sommers, John L. Darcy, Dorota L. Porazinska, Eli M. S. Gendron, Andrew G. Fountain, Felix Jacob Zamora, Kim Vincent, Kaelin M. Cawley, Adam J. Solon, Lara Vimercati, Jenna Ryder, Steven K. Schmidt

Geology Faculty Publications and Presentations

Although cryoconite holes, sediment-filled melt holes on glacier surfaces, appear small and homogenous, their microbial inhabitants may be spatially partitioned. This partitioning could be particularly important for maintaining biodiversity in holes that remain isolated for many years, such as in Antarctica. We hypothesized that cryoconite holes with greater species richness and biomass should exhibit greater partitioning between the sediments and water, promoting greater biodiversity through spatial niche partitioning. We tested this hypothesis by sampling frozen cryoconite holes along a gradient of biomass and biodiversity in the Taylor Valley, Antarctica, where ice-lidded cryoconite holes are a ubiquitous feature of glaciers. We …

Effectiveness Of Windrow Composting Methodology In Killing A Thermo-Tolerant Species Of Salmonella During Mortality Composting, Spencer Gabriel Myers

Master's Theses

In a large agricultural operation, such as the one at Cal Poly San Luis Obispo, disposal of deceased animals is an immense issue. The cost of transporting and rendering every dead animal is inhibitory to the general function of the agricultural operations and their thin budget. Therefore, we propose that composting mortalities could be an economical alternative. Composting is a recognized method for taking animal waste products along with carbon waste and turning it into a pathogen-free, nutrient-rich topsoil. Carcass composting is in fact performed in other countries and states to varying degrees of success. However, the California EPA limits …

2018 Long-Term Summary Of Kentucky Forage Variety Trials, Gene L. Olson, S. Ray Smith, Jimmy C. Henning, Christopher D. Teutsch

Forage Symposium at the Kentucky Cattlemen’s Convention

Forage crops occupy approximately 7 million acres in Kentucky. Forages provide a majority of the nutrition for beef, dairy, horse, goat, sheep, and wildlife in the state. In addition, forage crops play an environmentally friendly role in soil conservation, water quality, and air quality. There are over 60 forage species adapted to the climate and soil conditions of Kentucky. Only 10 to 12 of these species occupy the majority of the acreage, but within these species there is a tremendous variation in varieties.

This publication was developed to provide a user-friendly guide to choosing the best variety for producers based …

The Microbiome Stress Project: Toward A Global Meta-Analysis Of Environmental Stressors And Their Effects On Microbial Communities, Jennifer D. Rocca, Marie Simonin, Joanna R. Blaszczak, Jessica G. Ernakovich, Sean M. Gibbons, Firas S. Midani, Alex D. Washburne

Faculty Publications

Microbial community structure is highly sensitive to natural (e.g., drought, temperature, fire) and anthropogenic (e.g., heavy metal exposure, land-use change) stressors. However, despite an immense amount of data generated, systematic, cross-environment analyses of microbiome responses to multiple disturbances are lacking. Here, we present the Microbiome Stress Project, an open-access database of environmental and host-associated 16S rRNA amplicon sequencing studies collected to facilitate cross-study analyses of microbiome responses to stressors. This database will comprise published and unpublished datasets re-processed from the raw sequences into exact sequence variants using our standardized computational pipeline. Our database will provide insight into general response patterns …

Socioecological Determinants Of Drought Impacts And Coping Strategies For Ranching Operations In The Great Plains, Tonya Haigh, Walter H. Schacht, Cody L. Knutson, Alexander J. Smart, Jerry Volesky, Craig R. Allen, Michael Hayes, Mark E. Burbach

National Drought Mitigation Center: Faculty Publications

In Great Plains rangelands, drought is a recurring disturbance. Ranchers in this region expect to encounter drought but may not be adequately prepared for it. Efforts to encourage drought preparednesswould benefit froma better understanding of the conditions under which managers make decisions to minimize the impacts of drought.We tested the direct andmoderating roles of the drought hazard and the social-ecological context on drought impacts and response. This study was conducted with ranchers in western and central South Dakota and Nebraska following the drought that began in 2012. We surveyed ranchers regarding the effects of the drought and their responses and …

Defining The Morphological Quality Of Fossil Footprints. Problems And Principles Of Preservation In Tetrapod Ichnology With Examples From The Palaeozoic To The Present, Lorenzo Marchetti, Matteo Belvedere, Sebastian Voigt, Hendrik Klein, Diego Castanera, Ignacio Díaz-Martínez, Daniel Marty, Lida Xing, Silverio Feola, Ricardo N. Melchor, James O. Farlow

Department of Earth and Atmospheric Sciences: Faculty Publications

The morphology of fossil footprints is the basis of vertebrate footprint ichnology. However, the processes acting during and after trace fossil registration which are responsible for the final morphology have never been precisely defined, resulting in a dearth of nomenclature. Therefore, we discuss the concepts of ichnotaphonomy, ichnostratinomy, taphonomy, biostratinomy, registration and diagenesis and describe the processes acting on footprint morphology. In order to evaluate the morphological quality of tetrapod footprints, we introduce the concept of morphological preservation, which is related to the morphological quality of footprints (M-preservation, acronym MP), and distinguish it from physical preservation (P-preservation, acronym PP), which …

Irrigation Water Quality—A Contemporary Perspective, Arindam Malakar, Daniel D. Snow, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

In the race to enhance agricultural productivity, irrigation will become more dependent on poorly characterized and virtually unmonitored sources of water. Increased use of irrigation water has led to impaired water and soil quality in many areas. Historically, soil salinization and reduced crop productivity have been the primary focus of irrigation water quality. Recently, there is increasing evidence for the occurrence of geogenic contaminants in water. The appearance of trace elements and an increase in the use of wastewater has highlighted the vulnerability and complexities of the composition of irrigation water and its role in ensuring proper crop growth, and …