Digital Commons Network^™

Modelling Basal Area Of Perennial Grasses In Australian Semi-Arid Wooded Grasslands, S. G. Marsden, K. C. Hodgkinson

IGC Proceedings (1977-2023)

In many semi-arid pastoral systems, landscape processes easily become dysfunctional. Shifts to less functional states may be irreversible, and have long-term consequences for pastoral profitability and social viability of rural communities. Typically, shifts to lower functional states involve a decline in perennial grasses (Hodgkinson, 1994). Here we develop a conceptual basis for modelling the basal area of perennial grasses in a semi-arid grassland and validate the model using data from a 10-year grazing study.

The Effect Of Manipulated Conservation Margins In Intensively Grazed Dairy Paddocks On The Biodiversity Of Pteromalidae And Braconidae (Hymenoptera: Parasitica), A. Anderson, G. Purvis, A. Helden, H. Sheridan

IGC Proceedings (1977-2023)

Conserving field margins provides an opportunity to enhance biodiversity in agricultural landscapes. The parasitoid Hymenoptera represent one of the most diverse and biologically specialised of all insect groups and play an important role in insect pest control (LaSalle & Gauld, 1993). The diversity of parasitiods in any habitat is theoretically likely to reflect the diversity of host taxa. The aim of this study was to assess the effects of field margin manipulations on the diversity of parasitoids as a wider indication of effects on general arthropod diversity.

Plant Diversity Patterns Along Altitudinal Gradient In Understory Communities Of Darkesh Region, Bojnord, Iran, A. Arjmandi, H. Ejtehadi, F. Memariani, Mansour Mesdaghi

IGC Proceedings (1977-2023)

The ecotone region of Darkesh with an area of 22,500 hectares is located in the Irano-Turanian xeric-continental bioclimatic zone of Khorassan-Kopet Dagh. To investigate the plant diversity patterns of understory communities along three elevation classes of 1100-1600, 1600-2100, and 2100-2600 m, 187 plots were sampled randomly and abundance and cover of species were recorded using 4-m² plots. Beta diversity and Hill indices were calculated by using R and PAST software. A total of 252 species were recorded including 31 perennial grasses. The most abundant grasses were Poa nemoralis, Poa bulbosa, Bromus sterilis, Brachypodium sylvaticum, and Dactylis glomerata subsp. glomerata …

Using Genetic Diversity In Deep Root Systems Of Perennial Forage Grasses And Rice To Capture Carbon In Tropical Soils, J. Arango, Daniel M. Villegas, R. N. Jauregui, J. A. Cardoso, C. Costa Jr., C. Rebolledo, M. F. Alvarez, M. Selvaraj, L. Rodriguez, M. Mayorga, P. Chavarriaga, A. Notenbaert, M. Quintero, M. Da Silva, Manabu Ishitani, M. Peters, I. Rao, Joe Tohme

IGC Proceedings (1977-2023)

Agricultural soils have the potential not only to be sinks of carbon dioxide (CO₂) but also to mitigate the emissions of this gas to the atmosphere, thus, alleviating global warming. Perennial tropical grasses and rice upland and lowland varieties exhibit a large untapped genetic diversity in their root systems (e.g., deep rooting ability, exudation rates and chemical composition) that, if unlocked, could contribute to increased food production in crop-livestock systems while enhancing soil organic carbon (SOC) in tropical regions. Naturebased solutions that improve crop adaptation and SOC storage in tropical soils could help to remove CO₂ from …

Salt Tolerance Mechanisms In Perennial Fodder Grasses, Edna Antony, B. Aravind, A. Amulya, T. Anushree, P. V. Rakshata, F. H. Savitha, M. B. Doddamani, P. V. Kuligod, Akbar, Vinod Kumar, K. Sridhar, Vijay Kumar Yadav

IGC Proceedings (1977-2023)

Salinity stress is one of the most damaging stresses in crop plants. It reduces the productivity of the soil and makes it unsuitable for crop cultivation. Fodder crops are considered the best alternative in such uncultivable land. Using salinity-affected land for pasture development is the best alternative to utilize such lands. However, the extent of salinity tolerance varies among different grass species. In this study, Pearl millet Napier hybrids (PMN hybrid) and guinea grass varieties were studied for salinity tolerance in artificially created saline soils in the ratio of 13:7:1:2 (NaCl: Na₂SO₄: MgCl: CaSO₄, …

Effect Of Soil Nitrogen And Water Content On The Establishment Of A Lolium Perenne L. And Trifolium Repens L. Pasture, M. F. Alonso, Oscar A. Balocchi, I. Calvache, O. Martínez

IGC Proceedings (1977-2023)

Climate change has decreased rainfall in Southern Chile affecting the productivity of the grasslands that sustain the dairy and beef cattle industries. These grasslands are mainly mixtures of Lolium perenne L. and Trifolium repens L. Thus, we study the response on the establishment of a mixture of these two species to three levels of soil water content and two levels of nitrogen (N) fertilization. The trial was carried out in containers sowed in a complete randomized block´s design. Soil moisture measurements were taken daily. N fertilizations was applied at the establishment and every 60 days. Leaf appearance rate was measured …

Impact Of Level Of Use On Plant Vigor And Weight Of Festuca Humilior And Calamagrostis Vicunarum, T. Edson, L. Aguirre, E. R. Flores

IGC Proceedings (1977-2023)

Tussock grasslands of Festuca humilior and Calamagrostis vicunarum cover a significant extension of the central Andes of Peru, constituting a plant association highly appreciated by cattle ranchers. The objective of this research was to estimate the cumulative impact of the level of use of the key grasses Festuca humilior and Calamagrostis vicunarum on plant height, vigor, and weight. This study was conducted in a humid grassland of regular condition located at 4186 masl in the Puna ecoregion. The variables evaluated were: plant height, basal and canopy diameter and plant weight. The experiment lasted two years in which individual plants from …

The Geologic History Of Primary Productivity, Peter W. Crockford, Yinon M. Bar On, Luce M. Ward, Ron Milo, Itay Halevy

Geosciences: Faculty Publications

The rate of primary productivity is a keystone variable in driving biogeochemical cycles today and has been throughout Earth’s past.¹ For example, it plays a critical role in determining nutrient stoichiometry in the oceans,² the amount of global biomass,³ and the composition of Earth’s atmosphere.⁴ Modern estimates suggest that terrestrial and marine realms contribute near-equal amounts to global gross primary productivity (GPP).⁵ However, this productivity balance has shifted significantly in both recent times⁶ and through deep time.^7,8 Combining the marine and terrestrial components, modern GPP fixes ≈250 billion tonnes of carbon …

Investigating Mobility In The Northern Balkans During The Fifth Millenium Bc Through Strontium Analysis Of Human Tooth Enamel, Aurélien Tafani

USF Tampa Graduate Theses and Dissertations

This research investigates how individual mobility among ancient populations in Romania during the Eneolithic, between 5000 and 4000 BC, may be related to the spread of the material culture known as Kodjadermen-Gumelniţa-Karonovo VI (KGK VI) that extended over most of southern Romania and Bulgaria. This work seeks to combine results on individual mobility with other lines of archaeological evidence to provide a better understanding of the social context and kinship relationships that were in place when these events took place.

Strontium isotopic analyses were performed on 130 individuals from two sites located in the southern Romania: 49 from Sultana and …

Volcanic Diffuse Volatile Emissions Tracked By Plant Responses Detectable From Space, Robert R. Bogue, Peter M. J. Douglas, Joshua B. Fisher, John Stix

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Volcanic volatile emissions provide information about volcanic unrest but are difficult to detect with satellites. Volcanic degassing affects plants by elevating local CO2 and H2O concentrations, which may increase photosynthesis. Satellites can detect plant health, or a reaction to photosynthesis, through a Normalized Difference Vegetation Index (NDVI). This can act as a potential proxy for detecting changes in volcanic volatile emissions from space. We tested this method by analyzing 185 Landsat 5 and 8 images of the Tern Lake thermal area (TLTA) in northeast Yellowstone caldera from 1984 to 2022. We compared the NDVI values of the thermal area with …

Examining Paleoshorelines In The Eastern Gulf Of Mexico: Insights On Sea Level History And Potential Areas Of Interest For Habitat Management, Catalina Rubiano

USF Tampa Graduate Theses and Dissertations

An inventory of multibeam bathymetry containing relict drowned and lithified paleoshorelines has been compiled and analyzed in the first ever shelf-wide investigation of paleo sea level indicators on the west Florida shelf (WFS). On the largest scale, the WFS is a wide and gently sloping terrain that is characterized by a carbonate-rich sediment regime. This framework coupled with the region’s tectonic stability provided a setting in which sea level changes since ~ 20 ka have been recorded to a remarkable degree of resolution in the form of paleoshorelines which formed at sea level and were subsequently drowned and preserved in …

Evaluation Of The Slip History And Holocene Activity Of The Strawberry Fault, Grant County, Oregon, Andrew Dunning

Dissertations and Theses

Lidar topographic data for the Strawberry Mountains, Oregon has revealed youthful fault scarps that likely result from Holocene-age earthquakes. We have mapped 27 km of fault scarps striking roughly east-west across the northern foothills of the Strawberry Mountains (Strawberry Fault, SBF) and another scarp lineament striking north-south along the uppermost John Day River 10 km to the south. SBF scarps are aligned with the bedrock John Day Fault, a reactivated Miocene structure that is accommodating distributed extension north of the Basin and Range region. The Strawberry Mountains sit near the interface of the extensional Basin and Range province to the …

Groundwater System Characterisation: Fortescue Alluvial Fan, Michael J. Donn, Olga V. Barron, Axel Suckow, Chris Turnadge, John A. Simons, Robert J. Paul, Christopher Schelfhout Dr

Natural resources commissioned reports

This report focuses on groundwater system characterisation in the region north of Newman, based on analysis of pre-existing data and data newly acquired during project activities. Groundwater system characterisation was an important research component supporting the assessment of managed aquifer recharge opportunities, using mine dewatering surplus generated (due to mining below the watertable) at large BHP Billiton Iron Ore operations in the eastern Pilbara mining zone, and aiming to support irrigated agriculture. The assessment area is located north of Ethel Gorge and covers the Upper Fortescue River floodplain and surroundings. The project added much knowledge to this largely ‘data-poor’ region, …

Transforming Agriculture In The Pilbara: Newman Managed Aquifer Recharge (Mar) Feasibility Assessment, Michael J. Donn, Joanne L. Vanderzalm, Olga V. Barron

Natural resources commissioned reports

In the Newman region, DPIRD commissioned an assessment of the potential for managed aquifer recharge (MAR) near Newman using surplus water resulting from mine dewatering as the water supply for irrigated agriculture. The objectives of the MAR assessment were to:

• identify focus area for MAR feasibility assessment within the initial larger area of interest for MAR
• assess the viability of MAR with mine dewater near Newman to support development of irrigated agriculture, in keeping with national and state MAR guidelines
• identify key risks associated with MAR with mine dewater for irrigation supply, and identify knowledge/investigation required to adequately assess risks …

U–Pb Zircon Ages, Mapping, And Biostratigraphy Of The Payette Formation And Idaho Group North Of The Western Snake River Plain, Idaho: Implications For Hydrocarbon System Correlation, Renee L. Love, Reed S. Lewis, Spencer H. Wood, Dennis M. Feeney, Mark D. Schmitz

Geosciences Faculty Publications and Presentations

Sedimentary deposits north of the western Snake River Plain host Idaho’s first and only producing oil and gas field. They consist of the lower to middle Miocene Payette Formation, the middle to upper Miocene Poison Creek and Chalk Hills Formations, and the Pliocene to lower Pleistocene Glenns Ferry Formation. Using new geochronology, palynomorph biostratigraphy, and geologic mapping, we connect updip surface features to subsurface petroleum play elements. The Payette Formation is a likely main source of the hydrocarbons, and acts as one of the reservoirs in the unnamed basin. Here, we redefine the Payette Formation as 0 to ~3,500 ft …

Kgs Joint Data, Steven L. Martin

Research Data--KGS

Joint orientation measurements collected by KGS personnel at rock exposures from 2009 to 2024. New joint data was collected using a Brunton compass. This data set is a compilation of joints measured by Steve Martin. There are three worksheets related to data structure. The joint location and joint measurement worksheets show a 1-to-many relationship. The 1to1 worksheet shows a 1-to-1 relationship between joint locations and measurements.

Version 2 uploaded December 2024, adding new data to existing set.

Kentucky Karst Dye Trace Database, Sarah M. Arpin, Benjamin W. Tobin, Maaz Fareedi, Adam Link, James C. Currens

Research Data--KGS

This dataset provides the geographical locations of karst groundwater basins, groundwater flowpaths, and dye injection/recovery points in Kentucky. Dye tracing is a common method used for understanding groundwater movement. Dye is poured (or injected) into a sinking stream, well, sinkhole, or body of water, where it is carried down-gradient by flowing water. The locations at which dye is recovered (typically at artesian springs) indicates a connection from injection to recovery site. This connection is refered to as a groundwater flowpath. Conducting multiple dye traces across an area allows for the interpretation of regional groundwater flow by assessing where flowpaths either …

Astronomical And Tectonic Influences On Climate And Deposition Revealed Through Radioisotopic Geochronology And Bayesian Age-Depth Modeling Of The Early Eocene Green River Formation, Wyoming, Usa, Benjamin T. Bruck, Brad S. Singer, Mark D. Schmitz, Alan R. Carroll, Stephen Meyers, Andrew P. Walters, Brian R. Jicha

Geosciences Faculty Publications and Presentations

The Wilkins Peak Member (WPM) of the Green River Formation in Wyoming, USA, comprises alternating lacustrine and alluvial strata that preserve a record of terrestrial climate during the early Eocene climatic optimum. We use a Bayesian framework to develop age-depth models for three sites, based on new ⁴⁰Ar/³⁹Ar sanidine and ²⁰⁶Pb/²³⁸U zircon ages from seven tuffs. The new models provide two- to ten-fold increases in temporal resolution compared to previous radioisotopic age models, confirming eccentricity-scale pacing of WPM facies, and permitting their direct comparison to astronomical solutions. Starting at ca. 51 Ma, the median …

The Development And Evolution Of The Soil Health Nutrient Tool (Aka Haney Test) After Ten Years Of Implementation In A Commercial Agricultural Laboratory, Lance Michael Gunderson

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The growing focus on soil health and regenerative agriculture has brought about the need for new integrated approaches for the analysis of soil. Prior, commercial agricultural laboratories relied on methods to measure chemical properties of the soil, such as pH and nutrients. The Soil Health Nutrient Tool (aka Haney Test) developed by Dr. Rick Haney (United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Blackland Research and Extension Station, Temple, Texas) integrates chemical and biological properties to provide a more holistic understanding of soil fertility management. Following adoption by commercial laboratories in 2013, criticisms regarding variability in measurements and lack …

Connecting The Nebraska Water Quality Index To The Aquatic Microbial Community Of The North Platte River Basin, Nebraska, Paula R. Guastello

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

The Nebraska Water Quality Index, under development by the Nebraska Department of Environment and Energy, summarizes in a single value eight environmental parameters that have been monitored in Nebraska for nearly 20 years. Water quality parameters including those used in the Nebraska Water Quality Index have been shown in previous studies to impact bacterial growth. As such, this index has the potential to correlate with the freshwater microbial community. Here, I relate the Nebraska Water Quality Index to microbial community composition and structure using 16S rRNA gene amplicon sequence data collected from the North Platte River Basin, Nebraska. This index …

Observed And Modeled Moulin Heads In The Pâkitsoq Region Of Greenland Suggest Subglacial Channel Network Effects, Celia Trunz, Kristin Poinar, Lauren C. Andrews, Matthew D. Covington, Jessica Mejia, Jason Gulley, Victoria Siegel

Geosciences Faculty Publications and Presentations

In the ablation zone of land-terminating areas of the Greenland Ice Sheet, water pressures at the bed control seasonal and daily ice motion variability. During the melt season, large amounts of surface meltwater access the bed through moulins, which sustain an efficient channelized subglacial system. Water pressure within these subglacial channels can be inferred by measuring the hydraulic head within moulins. However, moulin head data are rare, and subglacial hydrology models that simulate water pressure fluctuations require water storage in moulins or subglacial channels. Neither the volume nor the location of such water storage is currently well constrained. Here, we …

Modeling Overdraft-Driven Nitrate Transport In Shallow Wells For Mitigation And Scenario Planning, Jonathan Cronk

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

In Nebraska, average nitrate concentrations in groundwater have doubled since 1974, making water quality management more important than ever. As droughts, heat waves, and floods become more common climate events, understanding their impacts will be necessary to make informed management decisions. Emerging literature describes that drought correlates to an increase in the concentration of nitrate-N at domestic and irrigation wells, however the relative contributions of the mechanisms thought to be responsible is currently unknown.

This research assessed the impact of recharge and pumping rate changes as two mechanisms affecting nitrate-N concentration during drought, assessed the relationship between well depth and …

Experimental Studies On The Operation Of Agricultural Crops Mowing Unit With Simultaneous Chopping And Incorporation Of Stubble Into The Soil, Volodymyr Nadykto, Sergey Kiurchev, Tatiana Chorna, Taras Hutsol, Szymon Głowacki, Anatoliy Rud, Alona Shevtsova, Igor Ryabov, Katarzyna Szwedziak

Sociology Faculty Publications

For harvesting crops, one-phase and two-phase methods are most often used. When implementing the second one, mounted and trailed units are used. The latter is becoming less and less used due to the problems with movement stability in the horizontal plane because of the asymmetric layout. A stubble background, which is susceptible to solar and wind influences, is formed as a consequence of application of the mounted harvesting unit, As a result, the field’s soil in the inter-swath space intensively loses moisture. A harvesting unit based on a tractor with rear steerable wheels has been designed to eliminate this shortcoming. …

Water Efficiency & Sustainability In The Mountain West, 2022, Zachary Billot, Caitlin J. Saladino, William E. Brown Jr.

Environment

This fact sheet analyzes the effectiveness of state-level policies related to water usage, conservation, and sustainability for the Mountain West states of Arizona, Colorado, Nevada, New Mexico, and Utah in 2022. The original data are published in the “2022 State Policy Scorecard for Water Efficiency and Sustainability” report written by the Alliance for Water Efficiency.

Porosity And Permeability Analysis Of Treated And Untreated Soils At The Edwards Aquifer Authority Field Research Park: Report For The Edwards Aquifer Authority, Gina Alva, Jullia De La Cruz, Fernando Jaime Sepulveda, Jakob Merkelz, Fernanda Moreno, Adrian Rodriguez

Hydrogeology

A fundamental ecosystem service of soil is its capacity to initiate and regulate the storage of groundwater. Soil has the capability to store, transport and filter water through percolation and infiltration. The sustainability of water resources, considering both quantity and quality, is directly influenced by soil. Understanding the effects of soil on water transportation is important when trying to quantify how much water the soil retains, and how much water moves into. This is why assessments of soil porosity and permeability play a crucial role in identifying regions with favorable water retention capabilities around the Edwards aquifer region. This information …

Pleistocene Bats (Late Irvingtonian And Late Rancholabrean) From Nuckolls And Sherman Counties, Nebraska, Nicholas J. Czaplewski, Richard George Corner

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

We document rare finds of fossil bats from two localities representing the Pleistocene epoch in southern and central Nebraska, Albert Ahrens locality (No-104, late Irvingtonian age, Middle Pleistocene), Nuckolls County, and Litchfield (Sm-102, late Rancholabrean age, latest Pleistocene), Sherman County. The Albert Ahrens local fauna with strong boreal influence has produced two bats, Lasiurus cf. borealis and Cf. Myotis sp. The Litchfield local fauna, also showing a strong boreal influence, has yielded two bats, Eptesicus fuscus and Cf. Myotis, among a diverse Pleistocene fauna of small vertebrates and a pollen record indicating a boreal mixed conifer and deciduous woodland, …

Using Post-Season Tissue Nitrogen Concentrations To Predict Adequacy Of In-Season Nitrogen Management, Kyle Hoegenauer, Trenton Roberts, Carrie Ortel, Jarrod Hardke, Mike Richardson, Mike Daniels

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

High-yielding mechanized rice production requires large amounts of nitrogen (N) fertilizer, which can be particularly costly to producers when applied in excess. The development of a tissue test to detect overapplication of N to rice is needed. Nitrogen response trials arranged in a randomized complete block design were established to identify a critical concentration threshold for a tissue test to detect excess N availability. Rice stalk samples were collected from 0 to 20 cm above the soil within 5 days of harvest and analyzed for NO₃ −-N concentration. Two models were fit to the data to represent rice grain …

Roadway Floods And Their Associated Weather-Related Conditions: New Insights Using Cars 511 Data For State And Federal Highways In Nebraska, Usa, Logan R. Bundy, Mark Anderson, Clinton M. Rowe, Rezaul Mamood

Department of Earth and Atmospheric Sciences: Faculty Publications

This study examined roadway flooding event data provided by the Nebraska Department of Transportation via the Condition Acquisition Reporting System (CARS) 511 archive (2016–2021). With these data, a novel analysis was completed to further the understanding of where, when, and why (meteorologically) roadway flooding occurs on Nebraska state and federal highways. In the study period, 298 roadway floods occurred, with an annual median of 16 per year. There was a greater risk for roadway floods to transpire more frequently in eastern Nebraska, which was attributed to the spatial climatology of heavy rainfall and the higher density of roadways and rivers. …

Examining The Corn Seedling Emergence–Temperature Relationship For Recent Hybrids: Insights From Experimental Studies, Sahila Beegum, Charles Hunt Walne, Krishna N. Reddy, Vangimalla Reddy, Kambham Raja Reddy

Nebraska Water Center: Faculty Publications

Corn seedling emergence is a critical factor affecting crop yields. Accurately predicting emergence is crucial for precise crop growth and development simulation in process-based crop models. While various experimental studies have investigated the relationship between corn seedling emergence and temperature, there remains a scarcity of studies focused on newer corn hybrids. In the present study, statistical models (linear and quadratic functional relationships) are developed based on the seedling emergence of ten current corn hybrids, considering soil and air temperatures as influencing factors. The data used for model development are obtained from controlled soil plant atmospheric research chamber experiments focused on …

Water Chemistry Variability In Peacock Springs Cave System And Spring Basin: Impacts On Continuous Monitoring Of Karst Aquifers, Mahnoor Kamal

USF Tampa Graduate Theses and Dissertations

The Upper Floridan Aquifer (UFA) is a highly transmissive and heterogeneous karst aquifer that makes it acutely susceptible to pollution. Rapid and extensive water quality changes in nutrients at springs draining the UFA have prompted intensive monitoring at several priority springs, including continuous and discrete water quality sampling. Springs, however, are a discrete discharge point of an often-expansive phreatic cave network that can intersect different land uses and thus drain distinct geographic areas of a springshed. The extensive network contains convergent passages from deep and shallow aquifer regions and may contribute to varying water chemistry across passages resulting in water …