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 15 of 15 for “"grassland soils"”.
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Soil properties, lime and phosphorus fertiliser management affecting grass production in Ireland
… nutrient and is an essential element required by grasslands for optimum production and herbage P concentration for animal dietary requirements. However phosphorus is a finite resource and efforts must be made to reduce P needs in grassland to prolong its remaining lifespan. In Ireland current P …
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Limitations of savanna trees in the highveld grasslands of South Africa
Many grassland areas throughout the world may support a woody biomass if fire is suppressed. It is puzzling that fire-tolerant savanna trees do not grow in these grasslands. The Highveld grasslands of South Africa are one such grassland. Hypotheses including fire, human intervention, grass …
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Consequences of nutrient enrichment for soil organic matter cycling in grasslands
… C in the majority of biomes, especially grasslands. Consequently, either positive or negative changes to grassland soil C sequestration could feed back to influence the global C cycle. Unfortunately, the effects of nutrient enrichment on SOM cycling remain uncertain. In my dissertation, I …
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Soil Respiration of Native Saskatchewan Grassland Calculated from Carbon Dioxide Concentration Profiles
… to obtain CO2 concentration profiles on native grassland and cultivated soils. The CO2 concentration gradients were then used to calculate CO2 flux through successive soil layers. Production of CO2 by these layers was calculated from the flux through the upper and lower plans of a soil layer. …
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Studies on the aerobic bacterial flora of a New Zealand tussock grassland soil
… aerobic bacterial flora of a single New Zealand grassland soil whose characteristics are described. The 4 parts deal respectively with the characterisation of the aerobic heterotrophic bacterial flora, the activity this flora as measured by a number of different techniques, nitrification and …
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Petroleum effects on soil microbial communities
… aimed to evaluate microbial community shifts in soils under crude oil contamination and assess the effects of Biodiesel co-product (BCP) as a protecting agent of soil microbiota under crude oil addition. We used soils from the Trindade Island and from the Highfield research station at Rothamsted …
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Environmental change and human interaction in the western Mediterranean over the long term: a comparative study from Sardinia
… and the radiocarbon-dating of on-site buried soils and slope deposits from upland environments found that the Late Neolithic period (ca. 6,000-5,500 BP) corresponded with a marked phase of anthropogenic soil loss at times of regional environmental changes, followed by intense Copper Age (ca. …
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How Are Rare Species Maintained?: Reproductive Barriers Between Layia jonesii, a Rare Serpentine Endemic, and L. platyglossa
… <em>L. jonesii</em> is isolated to dry soils near serpentine rock outcrops and <em>L. platyglossa</em> is located on slightly deeper grassland soils surrounding the rock outcrops. On hillsides where they co-occur, I observe two morphologically distinct species, therefore the two species …
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Studies of the mechanisms of stabilization of organic matter in semiarid soils
… size fractions obtained from two semiarid grassland soils. Microbial transformations of C and P were assessed as indices of relative availability of native forms of these elements. Chemical recalcitrance was hypothesized to increase with increasing particle size. Stabilization by clay …
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Using bio-manipulation to optimise nutrient management within intensive farm systems
… and microbial properties of agricultural soils. This uncertainty reduces the likelihood that land owners and land managers will adjust farming practices in order to deliver more widespread use of organic amendments to support production. In this context, the research reported in this …
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Natural gradients in temperature and nitrogen: Iceland represents a unique environment to clarify long-term global change effects on carbon dynamics
… and N input effects on C dynamics in subarctic grasslands, which cover ca. 10% of the global terrestrial surface. The primary advantage of natural gradients is that equilibrium states can be observed. Further, their typical wide and continuous nature allows to study the full range of global …
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Microbial diversity and activity in temperate forest and grassland ecosystems
… bacteria diversity and function in forest and grassland soils with focus on the influence of (a) functional group identity of grassland plants (legumes, grasses, forbs), (b) grassland plant species richness and (c) tree species, on AOB diversity and function. Another objective of this research …
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Phosphorus speciation, agronomic performance and soil nutrient testing for waste recovered fertiliser use in Northern Irish soil
… P in the iron and aluminium rich basalt soils of the Antrim Plateau, which covers a third of NI. An alternative advanced speciation method, namely DGT (Diffusive Gradients in Thin films), could be used instead to assess P bioavailability in these and other soil types in NI. The method has …