Digital Commons Network^™

Visualization Of Paleocurrents On A Web Application Using Gplates, Anjan Sapkota

MS in Computer Science Theses

Paleocurrents are flow directions derived from features of sedimentary rocks that reveal the direction of the current of wind or water that deposited the sediment. In 2015, Brand et al. created a global database of paleocurrents, which contains over 1,000,000 measurements worldwide: North America, South America, Australia, Great Britain, parts of Western Europe, China, Africa are fairly well represented; Antarctica, Eastern Europe, and Asia are modestly represented and Russia is poorly represented. The contribution of this thesis is a web application that uses the GPlates’ Application Programming Interface (API) to visualize global paleocurrents through time in an interactive way based …

A Day In The Badlands: A 52 Million-Year-Old Safari Adventure, Devra Hock-Reid, Judy Diamond, Jenn Paul

Zea E-Books Collection

with Amy Chew, Christopher Gilbert, Ross Secord, and Stephen Chester

Illustrations by Jenn Paul • Book design by Aaron Sutherlen

About the Badlands Fossils -- This story tells about the fossils of ancient animals found in the Wind River and Bighorn basins of Wyoming. Wyoming’s rich fossil record tell us about amazing animals from millions of years ago. About 66 million years ago, an asteroid slammed into the Earth, causing devastating changes that led to the extinction of dinosaurs. As the planet began to recover, it was much warmer than today, allowing palm trees and other tropical plants to grow …

Performance Of Acoustic Telemetry And Space Use Of Pallid Sturgeon In The Lower Platte River, Nebraska, Christopher F. Pullano

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

Pallid Sturgeon (Scaphirhynchus albus) are centenarian, potamodromous, rheophiles that historically occupied the Missouri River and Mississippi River basins. Listed on the U.S. Endangered Species Act in 1990, population declines are attributed to habitat fragmentation and degradation, as well as overharvest, and hybridization. A knowledge gap exists regarding the extent to which tributaries facilitate key life stages for Pallid Sturgeon. This study evaluated the capacity of acoustic telemetry to monitor the movements of Pallid Sturgeon in a shallow, braided tributary to the Missouri River. The specific objectives were to (1) evaluate the environmental variables influencing the performance of acoustic …

Occupancy Of Fish Species Of Greatest Conservation Need And Temporal Patterns Of Assemblage Occurrence In Sandhills Ecoregion, Nebraska Streams, Braxton M. Newkirk

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

Fish species’ occurrence is influenced by environmental conditions across multiple spatial and temporal scales. Alteration to stream systems has the potential to affect occurrence patterns of fish species. Stream systems of the North American Great Plains face threats originating from climate change and anthropogenic activities resulting in negative implications for many fish species. The Sandhills Ecoregion, Nebraska is considered one of the largest intact grasslands in North America, and thus may experience fewer threats than surrounding areas. Stream systems of the Sandhills Ecoregion are home to 12 fish species of greatest conservation need (SGCN). Little context exists regarding the environmental …

The United States National Security And Policy Implications Of Desertification, Eric Olvera

Open Access Theses & Dissertations

Contemporary climate security literature reveals that desertification appears to be overlooked as a climate change security threat to the United States (US). This investigation demonstrates that an inequity exists between sea-level-rise- and desertification-based climate security literature. This inequity may reveal that the US may be ignoring desertification at a time when land use in some dryland areas is reaching a critical point where it can no longer support human activity. Due to the interdisciplinary nature (science and security) of this work, a review of the terminology used in the article is provided to establish a baseline understanding of “desertification” and …

Using Luminescence Dating To Investigate Geomorphic And Archaeologic Features At The Wiggins Fork Bison Jump Complex, Northwestern Wyoming, Emma T. Krolczyk

All Graduate Theses and Dissertations, Fall 2023 to Present

The Wiggins Fork Bison Jump Complex, located in northwestern Wyoming, is comprised of thousands of human-placed rock piles, known as cairns, that were placed within lines to form an extensive network of drivelines and funnels leading to cliffs or steep slopes. These archaeological features were used by Native Americans as a bison hunting method, where the animals were driven off cliffs for harvest. This research uses luminescence dating, which determines when sediment was last exposed to sunlight, to date the timing of driveline construction and the deposition ages of the underlying river deposits.

Research focused on Jump #4, which had …

Microplastic Degradation Compared Among Dated Salton Sea Strandlines, Maria Alejandra Roman Medrano

Loma Linda University Electronic Theses, Dissertations & Projects

This thesis investigates the environmental degradation of plastic materials, with a focus on polyethylene terephthalate (PET), through a multi-phase study conducted at the Salton Sea, a closed-basin lake in a semi-arid region of California. The research addresses three core objectives: (1) developing a microplastic (MP) extraction method tailored for clay-rich sediments, (2) characterizing surface degradation of various plastic types, including PET, BoPET, HDPE, LDPE, and EPS, using advanced microscopy and spectroscopy, and (3) examining the long-term weathering of PET through samples collected from dated lake strandlines.

The extraction protocol successfully isolates MPs without oxidation, using ZnCl₂ and extended soaking to …

Implementing Organic Fertilization Practices To Improve Aloe Vera Growth And Soil Health In The Lower Rio Grande Valley, Isaiah Edward Jaramillo

Theses and Dissertations

Aloe vera (L.) (Aloe) Burm. f., is valued for its applications across the cosmetic, medicinal, and food industries due to its leaf gel. In the aloe industry, the extraction of gel from leaves generates significant quantities of organic waste, which presents an opportunity to repurpose this material as an amendment in aloe cultivation. While Aloe is renowned for its resilience, understanding the feasibility of using these organic shavings as a soil fertility amendment in aloe production is critical. This research aims to identify sustainable fertilization methods for Aloe that can maintain and/or improve crop yield while enhancing soil health. This …

Leveraging High-Frequency Water Quality Data And Machine Learning For Monitoring Harmful Algal Blooms, Ibrahim Busari

All Dissertations

Freshwater management is one of the most critical resources on the earth due to the plethora of water use and its limited availability. Increased algae proliferation is one of the significant problems of freshwater bodies that is triggered by nutrient enrichment and enabling conditions such as light and warm temperatures. This algal proliferation is toxic to the ecosystem through their biomass and potential toxin production that can cause hypoxic conditions and is often referred to as Harmful Algal Blooms (HABs). Current monitoring approaches include laboratory analysis of water samples to observe algal cells, monitoring of water quality parameters using water …

Carbon Dioxide Dynamics In The Carbonate Critical Zone, Savoy Experimental Watershed, Arkansas, Usa, Michael Darvin Jones

Graduate Theses and Dissertations

The dynamics of carbon dioxide (CO₂) within the Earth’s critical zone (CZ) are essential for driving spatial and temporal variations of carbonate dissolution and precipitation, which are fundamental to subsurface porosity and permeability development. However, there is still a significant knowledge gap regarding the patterns of CO₂ transport and production within the carbonate critical zone (CCZ). In this study, we investigated these dynamics within a mantled karst terrain at the Savoy Experimental Watershed (SEW) in Northwest Arkansas.

Previous monitoring of partial pressure of CO₂ (PCO₂) and dissolution rates at karst springs in …

Invertebrate Functional Diversity Of Fossils From Arrow Canyon, Nevada, Nathaniel Valentine

Undergraduate Research Symposium Podium Presentations

Paleontology can be used to study how ecosystems evolve and respond to changes in the environment. Here we examine invertebrate fossils from the Pennsylvanian, a time period that ranged from 323.2 to 298.9 million years ago, which are preserved along the walls of Arrow Canyon (Nevada) in the Bird Spring Formation. We surveyed three sites within the canyon, and used data from the Paleobiology Database to create a list of taxa found on the canyon from this time interval. Although ecosystems have traditionally been studied using the composition of the ecosystem (the number of species), recent work has shown that …

Red Harvester Ants Pogonomyrmex Barbatus (Smith, 1858) (Hymenoptera: Formicidae) Do Not Distinguish Between Sorghum Head Mold Symptomatic And Asymptomatic Seeds, Lilly Victoria Elliott-Vidaurri, Hannah J. Penn, Robin A. Choudhury

School of Earth, Environmental, & Marine Sciences Faculty Publications

Red harvester ants, Pogonomyrmex barbatus (Smith, 1858) (Hymenoptera: Formicidae), common in the Lower Rio Grande Valley of Texas, are known to gather seeds from areas around their nests and store the seeds inside their nests for later consumption. As these ants often nest in and near agricultural fields, some of these seeds may be from crops and may also be infected with fungal plant pathogens. These pathogens can degrade seed coats and may cause the seeds to rot within the ant nests, decreasing storage time and potentially spreading the pathogen to other stored seeds. We studied how head mold, a …

Human Impacts On Mammal Diversity From The Pleistocene To The Present, Carson P. Hedberg

Biology ETDs

Humans have fundamentally altered the planet’s biodiversity. It is critical to characterize these changes, but also to understand how they impact the structure and function of modern ecosystems. This dissertation investigates how anthropogenically mediated species losses and/or introductions influence ecological function and community structure in mammals across multiple temporal and spatial scales. We found that selective loss of large-bodied mammals over the Late Quaternary has led to severe losses in functional diversity in modern ecosystems, suggesting megafaunal mammals contribute distinct ecological functions. These changes to mammal diversity and distribution over millennia have altered both global patterns in functional diversity and …

Importance Of Tropical Pasture Seed Quality And Factors Affecting It In Smallholder Farming System, H F. Chin, C C. Wong

IGC Proceedings (1977-2023)

Most tropical pastures are associated with and confined to smaJlholder animal production in developing countries of the tropics, with the exception of Australia. At present, tropical pasture seeds are very variable and poor in quality, as tropical herbage seed production is relatively new compared with that for temperate systems. Many tropical species are relatively wild and have yet to be domesticated and selected for pasture use, let alone for seed production characteristics. The unfavourable production and storage environment of the wet tropics, coupled with a lack of appropriate technology, also contributes towards poor quality in tropical pasture seeds. In this …

Integration Of Pastoral And Non-Pastoral Uses On Temperate Rangelands With Cold Winters In Developed Countries, T J. Maxwell, W A. Laycock

IGC Proceedings (1977-2023)

The demands of the relatively wealthy and sophisticated societies of developed countries, with their substantial amounts of leisure time and discretionary income, are having an increasing impact on temperate rangelands in a variety of ways. Some parts of these societies are concerned to protect the landscapes, habitats, wildlife and solitude that can be found there, and wish to constrain any further development within these ecosystems; others also wish .to gain ready access to these resources for hunting, recreation and sport and believe that this requires the exclusion of domesticated livestock. Temperate rangelands are frequently used as water catchments and some …

Harvesting And Processing Techniques Of Tropical Grass And Legume Seeds For Smallfarmers, Lumyai Kowithayakorn, Chaisang Phaikaew

IGC Proceedings (1977-2023)

For smallfarmers of forage legumes and grasses in Thailand, manual harvesting and cleaning of leguminous seeds have been widely practised because of cheap and available labour. Tropical grasses produce more seeds than can be harvested; hence it is necessary to find means to improve harvesting and processing techniques in order to obtain high standards of both quality and quantity of seed. The main obstacles could be due to prolonged flowering nnd grain filling periods of individual seedheads resulting in the uneven ripening of seeds at harvest. Premature seeds cause low yields and low quality nt harvests in many species. Flowering …

Control Of Oxytropis Ochrocephala Bge. On The Mountainous Pasture Of Southern Ningxia, China, Guo Sijia, Chen Yizhong, Li Kechang, Xu Rong

IGC Proceedings (1977-2023)

Oxytropls ochrocephala Bge., the main poisonous plant on the mountainous pasture in southern Ningxia, has Increased dramatically as a result of overgrazing, The results of a series of studies on control of this plant show the following 3 ways are effective, (1) Spraying selective herbicide Butylate which makes the unpalatable dicotyledons drop by 37% and poisonous plant drop by 86.8% while the palatable grasses increase by 230%; the total yield is raised by 5.4%. This method can both control the poisonous plant and improve the pasture. (2) Spraying herbicides Starane, T-101, D-250, etc., which can specifically kill Oxytropis ochrocephala …

Commercial Seed Production Of Tropical Forage Grasses And Legumes In Costa Rica, Rosemary Sylvester-Bradley, J E. Ferguson

IGC Proceedings (1977-2023)

ABSTRACT A commercial seed enterprise with the initial objective of producing and marketing seeds of recently selected pasture species (Brachriaria dictyoneura and Arachis pintoi) oo small farms in the south west of Costa Rica is described. Farmers provide land and fencing and use the seed plots for grazing when not In the flowering period. The enterprise provides labour and technical organisation for establishment and seed production. Costs of organisation, and research and development work were greater than production costs; To achieve profitability the enterprise needs to increase net income possibly through share-cropping including animal production, and diversification into …

Ruzi Grass (Brachiaria Ruziziensis) Seed Production In North-East Thailand, Chaisang Phaikaew, Chanchai Manidool, Pimpaporn Devahuti

IGC Proceedings (1977-2023)

The recent expansion of beef and dairy production in Thailand has increased demand for pasture seed. Ruzi grass (Brachiaria ruziziensis) seed production has increased from 18 tin 1983 to 466 tin 1991. The; production sites are in the north east, where soils and climate are most suitable for seed production. 60% of all ruzi seed is being produced by smallfarmers; the rest is produced by government stations. Average farmer yield of rilzi is 400 kg • seed/h'a, with each farmer contracted 'to grow 0.32 h�� of ruzi grass, at a guaranteed price of US$2/kg; Abo·ut 2700 farmers are …

Model Herbage Seed Farm Establishment In South-West China, Guizhou Province, M P. Rolston, G W. Lill, R W. Brougham, Xie Jishi

IGC Proceedings (1977-2023)

A model herbage seed farm was established during 1983-1988 in Guizhou to provide a base for research, training and the product.ion of quality seed for smallholder pasture development. The site is at 26°N in a monsoonal subtropical zone at 1000 m asl. Mean monthly temperatures range from 4°C in winter to 25°C in summer. Seed yield potential of cultivars of perennial ryegrass (Lolium perenne), cocksfoot (Dactylis glomerata), white clover (Trifolium repens) and red clover (Trifolium pratense) was evaluated. Major nutrient limitations were identified, including responses to K and P. Management strategies to …

Efficiency Of Grassland Areas Of Desert Steppe In North China, Wang Ning, Wang Kezhi

IGC Proceedings (1977-2023)

On the desert steppe of Yanchi County of Ningxia Province, where 1he annual precipilalion is only 300 mm, some methods, including reducing unirrigated land, exploiting water resources, cultivating grasses, planting trees and developing animal husbandry, have been used to improve production. After 10 years the poor villages have become richer; the cultivated grassland is up to 44% of the total arable area and the forest cover to 15%; value of livestock farming output has increased by as much as 5 times, gross yields of grain have increased 1.5-fold, and the average income per capita increased more than 5-fold.

Breeding Switchgrass For Improved Animal Performance, K P. Vogel, K J. Moore, A A. Hopkins

IGC Proceedings (1977-2023)

Studies on breeding and evaluating switchgrass (Panicum virgatum L.) for improved animal performance have been conducted for the last 18 years. !ti vitro dry matter digestibility (IVDMD) has been increased 3 8 g/kg after 3 cycles of selection; demonstrating· that IVDMD of switchgrass can be improved using recurrent, phenotypjc selection. Digestibility of plant tillers collected at panicle emergence was an excellent predictor of IVDMD of progeny in pastures or swards during the growing season. Small improvements in IVDMD (20-30 g/kg} significantly improved average daily gains and gains/ha (17-24 %) of beer cattle (Bos taurus) grazing switchgrass. It should …

Small-Grain Forage For Winter Pastures, D J. Undersander, D P. Hutchenson

IGC Proceedings (1977-2023)

The paper summarises 2 studies comparing wheal (Triticum aestivum), barley (Horderim vulgare), rye (Triticale secale), and triticale (x Triticoseca/e) for fornge production and animal performance. Wheat, rye and triticale were planted in 10, 20 and 30 cm row spacings and grown over 2 winters in South Carolina. Porage yield from early­October plantings ranged from 2961 to 5000 kg/ha in 1986-87 and from l012 to 3400 kg/ha in 1987-88. Porage yield was highest from rye, most of the forage growth occurring in autumn. Wheat produced forage growth most uniformly throughout autumn and spring. In the …

Effects Of Lime And Fertilizer On The Establishment Of White Clover In The Falkland Islands, J A. Kerr, Rosie Poultney

IGC Proceedings (1977-2023)

White clover (Trifolium repens L.)-based pastures could improve low pasture and animal production in the Falkland Islands. However, establishment is difficult and expensive. Effects of lime and fertilisers containing nitrogen (N), phosphorus (P) and potassium (K) on white clover dry matter yield and root nodulation were experimentally assessed between 1986-88. Lime at 1 t/ha and 30 kg/ha P as triple superphosphate, separately improved clover yield. Nodulation was improved only by lime. Neither N nor K fertilisers affected on white clover establishment yields,

Winter Grazing Rough Fescue Grasslands With And Without Preconditioning On Annual Pasture, W D. Willms, L M. Rode, B S. Freeze

IGC Proceedings (1977-2023)

Winter grazing of the fescue prairie is desirable to reduce the cost of feeding preserved forages and to conserving the native prairie. Rough fescue (Festuca campestris Rydb,), the dominant and most productive forage species in the foothills region, is highly sensitive to summer grazing but tolerates grazing while dormant. Since the forage quality declines after senescence, and the energy requirements increase in winter, this study was made to determine the feasibility of winter gmzing pregnant Hereford cows with and without preconditioning on annual pasture. The study, replicated over a 4-year period {n=4), used a 2x2 factorial design representing native …

Improvement Strategies In Winter Cold Temperate Rangeland Ecosystems With Particular Reference To Extensive Grazing Lands Of Iran, A Koocheki

IGC Proceedings (1977-2023)

Traditional land use systems in Iran have been divided between crop production and livestock grazing. Grazing land management in most parts is based on pastoral nomadism which operates between plains as winter grazing lands and mountains as summer grazing lands. Mountainous areas are an important source of food and feed production for nomads and their herds. In Iran two main ranges of mountains, Elburz and Zagros, are the summer territory of nomadic pastoralists. At present 1.5% of total population of the country are nomads. They contribute as much as 27% of value added in the animal industry of the country. …

Winter Cold Temperate Rangelands: Improvement Strategies For Intensive Rangeland Ecosystems, B E. Allan, D Scott

IGC Proceedings (1977-2023)

Transfer of developed grassland technologies to rangelands is discussed in terms of environmental gradients and the options and constraints they impose. Winier feed limitation can be overcome through conserved feeds and various in situ systems involving special purpose pastures and feed banks. General animal nutrition can be improved through intensive development, low input systems, better control of range utilisation and, where appropriate, correction of mineral deficiencies. The emphasis in seeking quick and easy solutions to rangeland management problems is questioned, A more informed, environmentally sound and sustainable approach to rangeland fanning atlitudes and management is proposed. A stepwise process to …

A Decade Of Monitoring Reveals A Dynamic Fish Assemblage On A Substantial Artificial Reef In The Texas Gulf Of Mexico, David Hicks, Ethan T. Getz, Richard Kline, Carlos E. Cintra-Buenrostro

School of Earth, Environmental, & Marine Sciences Faculty Publications

Fish communities on artificial reefs have rarely been monitored over long periods to evaluate success of reef deployment. Here, we used roving diver surveys to assess changes in fish assemblages on a large, reefed vessel during 2008–2017. Multivariate analyses revealed a dynamic community that stabilized after 5 years. Species richness increased and species dominance decreased during 2008–2017. The fish community shifted toward reef-associated species such as hogfish and pufferfish. Species composition shifted, but trophic structure was relatively stable, which suggested that functional groups may not reflect larger community shifts. Our results indicate that fish communities on artificial reefs are temporally …

Puccinellia (Puccinellia Ciliata) For Dryland Salinity Management, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Puccinellia (Puccinellia ciliata) is a potentially valuable fodder on waterlogged saline land. Puccinellia, Distichlis and marine couch are the most salt tolerant of the commercially available grasses. It is best suited to areas with more than 400mm annual rainfall and where the watertable is shallow over summer.

The Department of Primary Industries and Regional Development recommends that any dryland salinity management is part of a whole farm, and preferably a whole catchment, water management plan.

Excavated Tanks (Farm Dams), Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Guidelines and information for planning, legal requirements, design, construction and management of excavated tanks for water storage on farm.

Excavated tanks (farm dams) provide effective water storage wherever surface water run-off can be harvested for livestock, crop spraying, irrigation and domestic use on rural properties.

Excavated tanks for rainfall storage are common in the southern agricultural areas of WA.

Well-designed and constructed dams are farm assets, safe and require little maintenance.

Poor design and construction can lead to poor water harvesting and storage, excessive costs, downstream erosion and risks to property and people.

DPIRD recommends that excavated tanks should be …