Physical Sciences and Mathematics Commons^™

Working Within Constraints: Managing African Savannas For Animal Production And Biodiversity, J. T. Du Toit

IGC Proceedings (1997-2023)

The mean density of livestock biomass on African rangelands now greatly exceeds that of indigenous large herbivores, although livestock cannot fully substitute for wildlife with respect to co-evolved ecosystem processes involving herbivory. The dominance of livestock in semi-arid rangelands is largely due to water provision, which uncouples livestock population dynamics from the rainfall-driven trajectories followed by indigenous ungulate species in wildlife areas. Ecological sustainability cannot be achieved with a few exotic species maintained at unprecedented biomass densities in savanna ecosystems, which are evolutionarily adapted for species-rich communities of ungulates of a wise range of sizes. Integrating wildlife and livestock in …

Challenges And Opportunities For Sustainable Rangeland Pastoral Systems In The Edwards Plateau Of Texas, J. W. Walker, J. L. Johnson, C. A. Taylor Jr.

IGC Proceedings (1997-2023)

This paper focuses on pastoral systems in an area of west-central Texas known as the Edwards Plateau. These rangelands have a combination of grass, forb and browse species and are used primarily for combinations of grazing by cattle, sheep, goats and wildlife. A major ecological challenge is woody plant encroachment. Stocking rate is the major factor affecting sustainability and historically this area was heavily grazed. Today the stocking rate is half or less of its historical peak. Species of livestock has shifted from predominantly small ruminant to cattle. About 70 % of pastoralists use some sort of rotational grazing system. …

Diversity And Variation In Nutritive Value Of Plants Growing On 2 Saline Sites In Southwestern Australia, H. C. Norman, R. A. Dynes, D. G. Masters

IGC Proceedings (1997-2023)

In south-western Australia 10% or 1.8 million ha of the farmed area is affected by dryland salinity and a further 6 million ha are at risk of salinity (NLWRA, 2001). Animal production from saltbush (Atriplex spp.)-based pasture systems represents the most likely large-scale opportunity for productive use of saline land in the short to medium term. Feeding saltbush-based pastures as a maintenance feed during the prolonged autumn feed gap typical in Mediterranean-type climates maximises their economic value. The aim of this study was to explore the diversity and nutritive value of plants that typically persist in saltbush-based saltland pastures.

The Long Road To Developing Native Herbaceous Summer Forage Legume Ecotypes, J. P. Muir, T. J. Butler, W. R. Ocumpaugh

IGC Proceedings (1997-2023)

Only a handful of well-adapted herbaceous summer forage legumes are currently marketed for drier regions of North America and even fewer are true natives. There is a growing demand for native germplasm in the region as a new generation of landowner attempts to return grasslands to a semblance of their original species and diversity. The objective of this paper is to describe preliminary research results of a grasslands team collecting, studying and promulgating native leguminous germplasm in Texas.

Mortality Model For A Perennial Grass In Australian Semi-Arid Wooded Grasslands Grazed By Sheep, K. C. Hodgkinson, W. J. Muller

IGC Proceedings (1997-2023)

No abstract provided.

Selecting Grassland Species For Saline Environments, M. E. Rogers, A. D. Craig, T. D. Colmer, R. Munns, S. J. Hughes, P. M. Evans, P. G. H. Nichols, R. Snowball, D. Henry, J. Deretic, B. Dear, M. Ewing

IGC Proceedings (1997-2023)

In Australia, around 5.7 million hectares of agricultural land are currently affected by dryland salinity or at risk from shallow water tables and this figure is expected to increase over the next 50 years (LWRA, 2001). Most improved grassland species cannot tolerate the combined effects of salt and waterlogging and, therefore, the productivity of sown grasslands in salt-affected areas is low. However, there is potential to overcome the lack of suitably adapted fodder species by introducing new, salt and waterlogging-tolerant species and by diversifying the gene pool of proven species. Potential species include exotic, naturalised and native Australian grass, legumes, …

Grazing Animal Production Systems And Grazing Land Characteristics In A Semi-Arid Region Of Greece, I. Hadjigeorgiou, G. Economou, D. Lolis, N. Moustakas, G. Zervas

IGC Proceedings (1997-2023)

Rough grazing in Greece cover about 40% of the total land area, is publicly owned and managed extensively (Hadjigeorgiou et al., 2002). The Prefecture of Larisa is in the centre of Greece, and has 212,000 ha of rough grazing land, with a variable topography ranging from sea level up to 3,000 m a.s.l. This area is utilized by a total population of 135,000 LU (mainly sheep, goats and some suckler cows), which consumes annually an appreciable fraction of their total nutrient requirements from rough grazing.

The Productivity Of Coastal Meadows In Finland, R. Nevalainen, S. Jaakola, A. Huuskonen, J. Kiljala, E. Joki-Tokola

IGC Proceedings (1997-2023)

The coastal meadows of Finland have gained a new interest as a summer pasture for cattle. These habitats have great historical, aesthetic and biological value (Pessa & Anttila, 2000). Typical features of the coastal meadows are the varying vegetation zones and wet, sometimes waterlogged, soils. The meadows are important nesting and feeding habitats for many water birds. When grazing ceases, reeds, trees and shrubs take over and the area loses its openness. Lately the amount of grasslands and pastures has drastically declined all over Europe. In Finland, the area of semi-natural biotopes has decreased to 1% of what it had …

Grass And Forage Plant Improvement In The Tropics And Sub-Tropics, Liana Jank, C. B. Do Valle, Rosangela M. S. Resende

IGC Proceedings (1997-2023)

1. The majority of tropical and subtropical forage grass genera and/or species have not yet been collected, or need further collection to be representative of their natural distribution.
2. New biotechnological techniques will only result in the release of superior forage cultivars if supported by strong breeding programs.
3. More funding and investment in the formation of strong public research teams in forage conservation and improvement are needed to guarantee the sustainability of tropical and subtropical pasture-based livestock systems in the future.
4. The creation of a permanent international working group on tropical and subtropical forages is essential to assist the International Plant Genetic …

Reconnaissance Of Landslides And Debris Flows Associated With The July 2022 Flooding In Eastern Kentucky, Matt M. Crawford, Zhenming Wang, Seth Carpenter, Jonathan Schmidt, Hudson J. Koch, Jason M. Dortch

Report of Investigations--KGS

Between July 25 and July 30, 2022, a series of convective storms generated approximately 14–16 inches of rainfall across parts of eastern Kentucky, predominately in Clay, Leslie, Perry, Breathitt, Knott, and Letcher Counties. The peak rainfall occurred on the evening of July 27 and the morning of July 28, with the hardest-hit areas experiencing more than 10 inches in a 24-hour period. The historic rainfall led to catastrophic flooding along many rivers and streams, but also triggered widespread landslides and debris flows that damaged roads, homes, property, and other infrastructure. Once initial relief and recovery efforts were established, the Kentucky …

Using 3-Dimensional Mapping To Determine The Possibility Of Structural Control On Development Of The Upper Ordovician Lexington Limestone, Central Kentucky, U.S.A., Sean Davis

Theses and Dissertations--Earth and Environmental Sciences

The upper Lexington Limestone of Late Ordovician age has been interpreted to represent a structurally controlled, complex, facies mosaic. This facies mosaic has historically been interpreted to be a carbonate buildup of shoal complexes with interbedded shale units with intertonguing facies. Due to relatively recent advances in geographic-information-systems (GIS) mapping technologies, it is possible to generate three-dimensional (3-D) compatible maps to offer insight to the complexities of the upper Lexington Limestone and to determine if structural control affected the distribution of members. The resulting two-dimensional (2-D) and 3-D maps show that basement faults likely exerted a significant influence on facies …

The Appalachian System Of Basins And Platforms As A Tectonostratigraphic Analogue To The Barents Sea Shelf: Where Arctic Meets The Appalachians, Gustavo De Aguiar Martins

Theses and Dissertations--Earth and Environmental Sciences

Divided between Norway and Russia, the Barents Sea shelf (BSS) is an ~1.4 million km² Arctic province, containing significant hydrocarbon accumulations. However, much of the area is frontier, and geologic data are often restricted or unavailable. One strategy to mitigate lack of geologic data is the use of analogues from well-known, mature basins. Even though there have been attempts to use analogues to study the geology of the BSS, such use is limited. Moreover, no analogue, to my knowledge, has been capable of addressing the regional tectonostratigraphic development of the shelf as a whole.

In this research, the Appalachian …

Closing The Modern Seismic Gap Along The Teton Fault Via Seismic Mapping Of Mass Transport Deposits In Jackson Lake, Wy, Callia Jacqueline Cortese

Theses and Dissertations--Earth and Environmental Sciences

Terrestrial paleoseismological records along the Teton fault have historically indicated two-to-three major post-Pinedale (~14 ka) earthquake events, leaving an unresolved 6-9 m offset along the modern scarp. Recent studies of Jenny Lake have augmented this record, but the triggering mechanism is still equivocal until new paleo-earthquake records are developed. The earthquake record of the Teton fault is complicated by quiescence from ~5 ka to present, demonstrating the need for additional paleoseismic investigations. Compressed, high-intensity radar pulse (CHIRP) reflection data from Jackson Lake indicates multiple potentially seismically-induced mass transport deposits (MTDs). At least six MTD Groups representing chronostratigraphic intervals were interpreted …

A Source-To-Sink Analysis Of The Pantanal Basin (Brazil): Implications For Weathering, Erosion, And Landscape Evolution In The World's Largest Wetland, Edward L. Lo

Theses and Dissertations--Earth and Environmental Sciences

Large back-bulge retro-arc basins have limited information about the sediment composition, yet they comprise important parts of the stratigraphic rock record. The exorheic Pantanal Basin is the world's largest continental wetland that regulates many valuable ecosystem services (water storage, nutrient cycling, agriculture, ranching, tourism, and transportation). This dissertation is composed of three studies that utilize a suite of tools to examine the most fundamental basin-wide source-to-sink sediment processes and controls that affect the characteristics and distribution of modern sediments.

The first paper consists of a metadata analysis of 76 shallow tropical floodplain lakes in the literature with bathymetric data and …

Estimating Bedrock Shear Wave Velocity At Vsap, Paducah, Kentucky, Using Ambient Noise, Russel Rogers

Theses and Dissertations--Earth and Environmental Sciences

Due to the nature of the Mississippi Embayment region and its vicinity to the New Madrid Seismic Zone, earthquake ground-motion site effects are potential hazards and quantifying the associated hazard is a necessary step for public safety. Measuring the V_s contrast between bedrock and overlying soil layers is necessary for site effect evaluation. Various methodologies for investigating shear wave velocity (V_s) profiles have been implemented in the Mississippi Embayment. However, these previous studies provided a wide range of bedrock Vs. In this study, microtremor array measurements, utilizing ambient background noise, were used to provide an additional estimate …

Assessing Compressed Air Energy Storage (Caes) Potential In Kentucky To Augment Energy Production From Renewable Resources, J Richard Bowersox, John B. Hickman

Report of Investigations--KGS

Fossil fuel power plants in Kentucky have some of the highest emissions of greenhouse gasses in the United States. One potential strategy for mitigating greenhouse gasses from electric power generation is the co-installation of Compressed Air Energy Storage (CAES) and a renewable source such as photovoltaic solar electricity generation (PV solar generation). CAES with complementary co-installed PV solar generation enhances stand-alone PV solar generation because CAES power is available at night.

CAES, however, requires both a site where large volumes of compressed air can be stored in the subsurface, and a heat source to prepare the stored air prior to …

Field Tests Of A Uav-Compatible Spectrometer To Evaluate Its Suitability For Detailed Soil Radon Potential Mapping, Alexandria Briahnne Thomas

Theses and Dissertations--Earth and Environmental Sciences

As part of ongoing research on radionuclide mapping and radon hazard characterization, field tests were performed to evaluate the suitability and limitations of a UAV-compatible gamma spectrometer. To date, this data set includes completed stationary data collection, mobile ground collection, multi-level UAV flights over a known material transition, as well as redundant ground and multi-level UAV data collection over a relatively uniform area. Total counts were used as a measure of soil radionuclide levels for our data collected above background. Although our test sites were in regions underlain by bedrock with high indoor radon levels, uranium counts were barely above …

Lateral Spacing Of Subsurface Poultry Litter Bands: Effect On Gaseous Nitrogen Emissions, Nutrient Uptake, And Maize Yield, Jason R. Simmons

Theses and Dissertations--Plant and Soil Sciences

Poultry litter (PL) is traditionally applied to no-till maize (Zea mays L.) cropping systems by surface broadcast. Poultry litter is nutrient dense, and it has been repeatedly shown that surface applied PL nitrogen (N) is vulnerable to losses to the atmosphere and nearby water systems. An application method was developed by USDA-Agricultural Research Service scientists for banding poultry litter (PL) below the soil surface with minimal soil disturbance to reduce ammonia (NH₃) volatilization and surface run-off. It is well documented that subsurface applied poultry litter (PL) reduces N losses by ammonia (NH₃) volatilization; however, the …

Hypogene Speleogenesis In The Grand Canyon; Observational, Mineralogical, And Geochemical Investigations From The Bopper Cave System, Sierra Heimel

Theses and Dissertations--Earth and Environmental Sciences

One of the most prominent features of the Grand Canyon is the iron-stained Redwall Limestone, which has been documented to contain extensive cave systems with significant storage potential in the karstic Redwall-Muav (R-M) aquifer. The hydrogeologic relationships between the R-M aquifer and cave formation in the Grand Canyon via descending (epigenic) surface waters have been well documented. However; the potentially large role of deeply sourced (hypogenic) waters rising from depth in relation to cave formation is poorly understood. The Bopper Cave System (BCS) is a relict feature of the ancient abandoned hydrologic system at Grand Canyon and displays unique network …

Discovery Of The Middle Mantle Transition Zone (Mmtz) And Its Geodynamic Significance, Yuping Wang

Theses and Dissertations--Earth and Environmental Sciences

Global mantle discontinuities and mantle transition zones are crucial to the earth’s evolution. By employing K-Means clustering, which belongs to cluster analysis in machine learning (ML), on shear velocity variation data, we generate heterogeneity percentage profiles for three different global tomographic models (Models S362WMANI+M, SEMUCB-WM1, and S40RTS). Key cluster percentage shifts, which are observed at around 400 km, 650 km, 1050 km, 1500 km, and 2700 km, suggest global mantle discontinuities at corresponding depths. All profiles also indicate a global discontinuity in the lower mantle between 2200 km and 2600 km. The middle mantle transition zone (MMTZ), bounded between 1050 …

Applications Of Digital Terrain Modeling To Address Problems In Geomorphology And Engineering Geology, Sarah Johnson

Theses and Dissertations--Earth and Environmental Sciences

This dissertation uses digital terrain modeling and computational methods to yield insight into three topics: 1) evaluating the influence of glacial topography on fluvial sediment transport in the Teton Range, WY, 2) integrating regional airborne lidar, UAV lidar, and structure from motion photogrammetry to characterize decadal-scale movement of slow-moving landslides in northern Kentucky, and 3) applying machine learning methods to surficial geologic mapping.

The role of topography as a boundary condition that controls the efficiency of fluvial erosion in the Teton Range, Wyoming, was investigated by using existing lidar data to delineate surficial geologic units, geometrically reconstruct the depth to …

Historical And Forecasted Kentucky Specific Slope Stability Analyses Using Remotely Retrieved Hydrologic And Geomorphologic Data, Daniel M. Francis

Theses and Dissertations--Civil Engineering

Hazard analyses of rainfall-induced landslides have typically been observed to experience a lack of inclusion of measurements of soil moisture within a given soil layer at a site of interest. Soil moisture is a hydromechanical variable capable of both strength gains and reductions within soil systems. However, in situ monitoring of soil moisture at every site of interest is an unfeasible goal. Therefore, spatiotemporal estimates of soil moisture that are representative of in-situ conditions are required for use in subsequent landslide hazard analyses.

This study brings together various techniques for the acquisition, modeling, and forecasting of spatiotemporal retrievals of soil …

Data Curation For Modeling Tall Fescue Biomass Dynamics With Dssat-Csm, M. B. Hanson, P. D. Alderman, T. J. Butler, A. Caldeira Rocateli

IGC Proceedings (1997-2023)

While models for predicting forage production are available to aid management decisions for some forage crops, there is limited research for a yield model designed specifically for tall fescue (Schedonorus arundinaceus). Therefore, our objective was to adapt an existing perennial forage model, the Decision Support System for Agrotechnology Transfer Cropping Systems Model (DSSAT-CSM) for predicting forage biomass of tall fescue in the southern Great Plains. To evaluate model performance, there must first be a high level of data manipulation and cleaning. In this project, a cohesive dataset combining biomass, weather, soil, and management data were structured into DSSAT …

Opportunities And Challenges In Augmenting Honey Bee Forage Resources With Pasture Legumes In Southern Australia, M. Kratz, M. Brown, M. T. Newell, R. C. Hayes

IGC Proceedings (1997-2023)

More than 80% of Australian honey is produced from native tree and shrub species. However, with increasing demands on public lands along with production risks posed by drought, floods and wildfires, there is a need to identify alternative forage resources to augment Australian honey production. With over 30 pasture legumes now available for agriculture in southern Australia, opportunity exists to increase the utilisation of some species with co-benefits to multiple production industries. However, there is little understanding of the potential value of most pasture legumes for honey production, and side by side comparisons are complicated by factors such as differences …

Can Changing Breeding Structure Serve As A Climate Adaptation Strategy? Evidence From A Comparative Study Of China And Mongolia, Y. Zhang, Z. Huang, J. Wang, Y. Huang, T. Hao, G. Xu

IGC Proceedings (1997-2023)

Under the influence of climate change, the vulnerability of grassland ecosystems in the Mongolian Plateau has increased. Correspondingly, herdsmen need to adopt more livelihood adaptation strategies to cope with changes in climate and grassland environment. The purpose of this study is to analyze the impact of breeding structure on grassland quality in Mongolian plateau. We select 20 border provinces/banners of Mongolia and Inner Mongolia Autonomous Region for research, and combined statistical data with remote sensing data of 2007-2016. The Normalized Difference Vegetation Index (NDVI) is used to quantify the grassland vegetation quality. Results show that there are differences in livestock …