Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 54 for “"arid environments"”.
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Development of resource-rich patches by soil-disturbing animals in arid environments
In arid landscapes limited resources are concentrated into fertile patches that allow greater productivity than would otherwise be expected. Fertile patches are created and maintained by processes that modify soil topography and interrupt the flow of resources across the landscape. These processes …
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Characterization of inducible antibiotic production by streptomycetes isolated from hyper-arid environments
… problem is the study of isolates from extreme environments, e.g. the Atacama Desert in Chile, adapted to those conditions and potentially encoding new specialised metabolites. Another method is to employ a multi-approach strategy for the discovery and elucidation of new metabolites combining …
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Design and optimization of a waste rock cover system for arid environments
… and hence acid generation is minimized. In arid environments the covers are generally designed as water infiltration barriers only. A saturated cover layer is required to prevent oxygen ingress and this is difficult to achieve in an arid climate. Ultimately, the success of a waste rock cover …
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A Framework for Development in Rural Arid and Semi-Arid Environments in Africa: The Somalia Case
… of sustainable jobs and businesses in rural, arid and semi-arid agricultural conflict zones of Sub Saharan Africa, focusing on Somalia's societal stabilization and conflict mitigation. This task requires developing risk-reducing measures for infrastructure and service delivery in rural, …
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Examining the Impact of Mercury on Waterfowl with Implications for Human Health and Water Management in Arid Environments
The work described in this thesis provides detailed insight into total mercury concentrations ([tHg]) observed in wood ducks along the lower Carson River watershed in western Nevada. Mercury (Hg) contamination of the Carson River dates back to the Comstock era mines in the late 1800's, where Hg …
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The evolution of annuality in association with a shift to more arid environments in the daisy genera Ifloga and Tricogyne
… history is often viewed as a model adaptation to arid environments. Annuality is predicted to have evolved in response to low adult survival and high seedling survival. In this study I evaluated the idea that increases in aridity should be associated with the evolution of an annual life history. I …
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Identifying Overwash Deposits in Arid Environments: Towards a Millennial-Scale Record of Cyclones and Makran Trench Tsunamis from Sur Lagoon, Oman
<p>Coastlines along the Arabian Sea are susceptible to marine inundation from Makran Subduction Zone (MSZ) earthquakes and tropical cyclones. Sediments deposited by these forms of inundation can expand the decadal instrumental record of events to include millennial timescales in regions without …
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Environmental and Climatic Constraints on Large-scale Camelina Production in Eastern Arkansas
… weather crop that is typically grown in semi-arid environments in the Western United States, usually as a spring crop, but sometimes during the winter. Research analyzing climate data and soil hydrology is important to better understand the environmental and terrain conditions necessary for …
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Palynological analysis from a bush karoo rat (Otomys unisulcatus) lodge near Prince Albert, South Africa
… region. The preservation of pollen in middens in arid environments from different parts of the world has great potential for the reconstruction of past vegetation. A lodge of the bush karoo rat (Otomys unisulcatus) was excavated near Prince Albert, South Africa, and the high numbers of …
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An assessment of wetland vulnerability to artisanal mining in Zimbabwe
… impact of artisanal mining on wetlands in semi-arid environments of sub-Saharan Africa. The findings underscore the detrimental effects of artisanal mining on wetland ecosystems, including habitat loss, biodiversity decline, riverbed sedimentation, and heavy metal pollution. Subsequently, the …
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A Comparison of Presence Only Suitability Models to Accurately Identify Prehistoric Agricultural Fields in Western New Mexico Through Remote Sensing
… practices of prehistoric cultures throughout the arid and semi-arid environments of western New Mexico by developing a remote sensing suitability model that will identify prime environments for a specific form of agricultural field, ak chin, that are often difficult to locate with standard …
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Dynamics of two South African floodplain forests
… is growing over the degradation of riparian environments through upstream abstraction, impoundments, altered flood regimes and increased incidence of low flows. These processes may lead to subtle or significant vegetation changes that will affect the understanding, management and conservation …
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The trend towards sociality in three species of southern African mole-rats (Bathyergidae) : causes and consequences
… occurring in species inhabiting increasingly arid environments. The strictly solitary Georychus capensis, the weakly social Cryptomys hottentotus hottentotus and the highly social Cryptomys damarensis were chosen for this investigation and my findings are compared, where possible, with the …
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Large-scale hydrological modelling in the semi-arid north-east of Brazil
Semi-arid areas are, due to their climatic setting, characterized by small water resources. An increasing water demand as a consequence of population growth and economic development as well as a decreasing water availability in the course of possible climate change may aggravate water scarcity in …
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Population genetic structuring in the common mole-rat, Cryptomys hottentotus hottentotus
… distributed across South Africa from extreme arid regions where low rainfall restricts dispersal for much of the year, to highly mesic areas where dispersal is facilitated all year round. In response to varying ecological constraints on dispersal, the species displays differential degrees of …
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The impacts of climate change on cattle water demand and supply in Khurutshe, Botswana
… water resources in Botswana and other semi-arid environments. A cattle water demand and supply model is developed to investigate the primary question of the thesis. The model is driven by rainfall and temperature over time as these variables largely determine cattle water supply and demand, …
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Implementation of a snow routine into the hydrological model WASA-SED and its validation in a mountainous catchment
… model WASA-SED (Water Availability in Semi-Arid environments - SEDiments) in catchments affected by snow and ice, a physically-based snow routine has been implemented into the model. The snow routine bases on the energy-balance method of the ECHSE (Eco-hydrological Simulation Environment) …
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Physical and Chemical Controls on Suffosion Development in Gypsic Soil, Culberson County, Texas
… in not only the Gypsum Plain, but for other arid environments with significant evaporite karst and gypsic soils as well.</p>
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Studies With Triazoles to Alleviate Drought Stress in GreenHouse-Grown Maize (Zea mays) Seedlings
In semi-arid environments, dry-land farming often exposes crops to drought stress. Although some plant species are well adapted to drought, most crops are not. Drought can reduce plant populations and limit growth and development in ways that have serious yield consequences. Planting at the …
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