Global ETD Search
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Showing 1 to 20 of 28 for “"soil resources"”.
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The Maya Footprint: Soil Resources of Chunchucmil, Yucatan, Mexico
… Yucatán are constrained by climate, thin soils, and low fertility. Despite this, the ancient Maya city of Chunchucmil Yucatán, Mexico, boasted an immense, dense, and wealthy population during the Middle Classic period (ca A.D. 400-700). Soil physical and chemical properties were explored …
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Spatio-temporal patterns of soil resources following disturbance in a 40-year-old slash pine (pinus elliottii Engelm.) forest in the Coastal Plain of South Carolina
… 1) to characterize the spatial patterns of soil and forest floor variables (moisture, pH, soil available nitrogen and phosphate, forest floor and soil carbon and nitrogen), 2) to examine the dynamics of these spatial patterns in response to two types of disturbance: whole-tree harvesting and …
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The Application of Pedology, Stable Carbon Isotope Analyses and Geographic Information Systems to Ancient Soil Resource Investigations at Piedras Negras, Guatemala
… studies and stable carbon isotope analysis of soil organic matter, combined with Geographic Information Systems (GIS) are three tools that can be used to answer crucial questions as to how the Maya managed their soil resources.</p> <p>GIS maps that indicated areas of best agricultural potential …
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The effects of local-scale resource heterogeneity on tropical tree communities
… species is their specialization for particular soil resource conditions. My dissertation research examines the soil resource and topographic niches of tropical forest tree species and how they affect local (< 1 km) tree community structure. This research draws upon data from eight large (24-50 …
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Ecology of Root-Feeding Insect Assemblages in Fire-Manipulated Longleaf Pine-Wiregrass Ecosystems
… they may respond to bottom-up factors such as soil resources, site productivity, and disturbance. My research addressed the following questions: (1) Do disturbance (fire), vegetative composition, soil resources, and fine root standing mass influence the structure of root-feeding insect …
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Restoring semi-arid lands with superabsorbent polymers under reduced precipitation and threat of Bromus tectorum invasion
… species. After disturbance, variability in resources as well as inherent soil moisture and temperature regimes may influence the susceptibility of an ecosystem to exotic species invasion. The invasive winter annual grass, Bromus tectorum (B. tectorum), is particularly competitive in …
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The effect of soil nutrient availability on resource allocation in tropical tree species
… strategies for resource use and acquisition. Soil resources influence productivity of tropical forests and the distributions of tree species across edaphically heterogeneous landscapes. My dissertation evaluates functional variation among tropical trees in nutrient use, and the implications of …
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A comparison of soil management systems for urban agriculture
Soil contamination is a universal concern of urban agriculture. Reliable soil management systems are desirable in order to provide ideal growing conditions for urban crops. Due to concerns such as soil contamination, alternative soil management systems (e.g. raised-beds) are necessary to provide …
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Earth to Earth : reconciling earthen dwellings with eroding loess landform : the case of Loess Plateau in China
… with loess deposits, a type of highly erodible soil consisting of less than 20% clay. Loess soil has topped eroding hills and valleys and supported an earthen construction tradition in loess landform territories. The Loess Plateau in China has been suffering from heavy soil erosion. Soil erosion …
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Influence of Transplanter Modification and Previous Crop on the Production of No-Till Dark Tobacco
… using<br />conventional tillage practices. Soil is cultivated multiple times throughout a growing season leading to an increased incidence of soil erosion. No-till systems have been growing in popularity with the advent of new technology that has enabled the practice to be performed …
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Wildland Fire in the Central Appalachian Mountains: Impacts on Above- and Belowground Resources
… fire's effects on water, vegetation, and soil resources in the central Appalachian Region. Moreover, the long-term efficacy of various types of timber harvests on forest fuel reduction was analyzed. Over fifty peer-reviewed articles were evaluated to characterize the effects of prescribed …
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Soil Management for Improved Rice Production in Casamance, Senegal
… estuaries where drought, salinity, acidity, poor soil fertility, and iron toxicity are the main limiting factors. In Casamance, average rice yield for local farmers is 1 to 2 tons per hectare (809 to 1618 pounds per acre), compared to worldwide average yield of more than 4 tons per hectare. The …
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Pedogenesis on the Sefton Coastal Dunes, NW England
… the use of pedo-properties to identify dune soil system responses to environmental change on the Sefton coast, based on the development of conceptual pedogenic models. Previous environmental change and shoreline dynamics are determined through O.S. maps and aerial photographs, while present …
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Roots as agents of soil change over time and as mediators of humanity’s imprint on Earth’s critical zone
… nutrient uptake, and in doing so redistribute soil resources. However, plant C for nutrient exchange strategies are not well understood and are proceeding amidst climate and land use changes that alter the amount of available C and nutrients, as well as the depth of root exploration. I examine …
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Fine Root Dynamics in a Pinus palustris Mill. Ecosystem: The Role of Sampling Interval and the Soil Environment
… Chapter 2 Abstract: We examined the impact of soil environmental variables (soil temperature, moisture, and available nitrate (NO3-) and ammonium (NH4+)) on the production, mortality, standing crop, turnover, and lifespan of Pinus palustris Miller fine roots using the minirhizotron technique. …
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Dynamics and Characterization of Soil Organic Matter on Mine Soils 16 Years after Amendment with Topsoil, Sawdust, and Sewage Sludge
… present state and future prospect of the world's soil resources has prompted scientists and researchers to address the issue of soil quality and sustainable land management. Soil quality research has focused on intensively-managed agricultural and forest soils, but the concept and importance of …
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Sorption of lead and arsenic on soil components and effectiveness of phosphates for remediating lead and arsenic contaminated soils
… of the potentially costly threats to water and soil resources as well as serious threats to humans. Clay minerals are potential binding agents for pollutants due to their high cation exchange capacity and large surface area. Laboratory investigations were undertaken to evaluate the effect of Fe …
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Soil health assessment of the Sanborn Field long-term experimental study
Soil health assessment uses a combination of potential indicators affecting soil processes to comprehensively monitor soil change, caused by cropping systems and soil management. The objectives of the study were to assess the effects of selected cropping systems, soil management and landscape slope …
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Application of multi-scale assessment and modelling of landfill leachate migration: implications for risk-based contaminated land assessment, landfill remediation, and groundwater protection
… across Britain, contaminating groundwater and soil resources as well as posing a threat to human health and local communities. There is an essential requirement for robust methodology when carrying out risk-based site investigations prior to risk assessment and remediation of landfill sites. …
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Competition For Above And Below Ground Resources Among Annual Species From The Plant To The Field: Quantification Analysis And Modeling
The ability to compete for resources is a main determinant of a plant?s success within a plant community. In the case of agricultural crops, competition among weeds and crop plants is a major determinant of crop yield losses. The objectives of this study are: i) to improve the understanding of the …
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