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 20 for “"microbial decomposition"”.
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Consequences of nutrient enrichment for soil organic matter cycling in grasslands
… cycles influence carbon (C) fixation and decomposition processes, nutrient enrichment affects global C stocks -- such as soil C. Carbon in soil organic matter (SOM) far outweighs vegetative C in the majority of biomes, especially grasslands. Consequently, either positive or negative …
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Decomposition of grasses in a South African savanna
… subtropical grasslands ecologists have ignored decomposition, because of the important role it plays in nutrient cycling, in terms of understanding how grass litter gets to the soil during the dry season. The major flaw is in the method~ employed to l investigate decomposition. In the prairies …
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Buried Surface Horizons in Saskatchewan Croplands Provide Insight into Microbial Soil Carbon Cycling and Development of Persistent Organic Matter
… serves as the primary C for the buried native microbial community. The goal of this thesis was to quantify and characterize the soil organic C (SOC) and examine microbial decomposition of this C in buried surface horizons, decades after burial. Surface (Ah) soils were sampled at 0-10 cm, buried …
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Decomposition of grasses in a South African savanna
… subtropical grasslands ecologists have ignored decomposition, because of the important role it plays in nutrient cycling, in terms of understanding how grass litter gets to the soil during the dry season. The major flaw is in the methods employed to investigate decomposition. In the prairies and …
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The Potential for Carbon Sequestration in Soils on Lignite Coal Minelands in East Texas
… sink because lignite carbon, which is subject to microbial decomposition, exceeds modern organic carbon in the soil up to this point.</p>
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A Quantitative Analysis of Interstitial Fluid-Chemistry and Limestone Dissolution Rates Within the Clastic Sediment of a Karst Aquifer Conduit, Mammoth Cave, Kentucky
… that of atmospheric background, presumably from microbial decomposition of organic material. The fluids were all under-saturated with respect to calcite (SI= -0.4 to -0.9), and limestone blocks buried at these levels all dissolved (rates from 0.8 to 21.9 g m -2 yr -1). These results suggest that …
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Import and decomposition of dissolved organic carbon in pre-dams of drinking water reservoirs
… proposed as a potential process facilitating the microbial decomposition of stable allochthonous DOC within the pelagic zone. To study organic carbon cycling under different hydrological conditions, quantitative and qualitative investigations were carried out in three pre-dams of drinking water …
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Determinants of blackwaters in the South Western Cape
… large amounts of polyphenols and potentially low microbial decomposition. Therefore, are the plant-soil dynamics a possible answer to variation in river colour? To answer this, the chemical correlates of rivers in the region, along with the in vitro leaching of the fynbos vegetation compared to …
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Structural characterization of spider coating petide [i.e., peptide] 1 and 2 of the black widow spider, Latrodectus hesperus
… potential for the products to have intrinsic antimicrobial activity. Studies have demonstrated a level of antimicrobial activity in native silk, a property that may have evolved in order to resist microbial decomposition, to protect developing eggs, and to resist decomposition or destruction by …
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Vegetation and microbial determinants of soil carbon isotopic composition
… in δ¹³C and δ¹⁵N profiles suggest that microbial decomposition may play an important role. The determinants of soil δ¹³C and δ¹⁵N, however, are complex and microbial decomposition and vegetation shifts are not the only mechanisms that drive the fractionation of the isotopes with depth. …
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Seasonal soil carbon fluxes in transitioning agricultural soils in Central Washington State: Relations to land-use, environmental factors and soil carbon-nitrogen characteristics
… Garden bed respiration is likely dominated by microbial decomposition of compost. Summer period soil CO<sub>2 </sub>flux correlates with SOC for all land-use types individually, while vegetable garden SOC and SON correlate with CO<sub>2</sub> flux annually. This suggests SOC influences summer …
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Greenhouse gas fluxes and root productivity in a switchgrass and loblolly pine intercropping system for bioenergy production
… the result of root respiration (RA) and microbial decomposition of organic matter (RH) releasing CO₂ as a by-product and is an important and large part of the global carbon (C) cycle. Accurate estimates of the two components of total soil respiration (RS) are required as they are …
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Rhizodeposition and its effects on C fluxes in the soil
… Although, rhizodeposition is a key driver of microbially mediated processes in the soils, it still remains the most uncertain component of the terrestrial carbon (C) cycle. The input of C through rhizodeposition occurs in temporal and spatial hotspots. The objective of Study 1 was to determine …
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Fire and herbivory effects on soil organic carbon stocks and soil greenhouse gas emissions from South African grasslands and savannas: Implications for global change
… C:N) foliage and litter that are resistant to microbial decomposition. This may contribute to the stable SOC pool, while reducing fluxes of all soil greenhouse gases. By contrast, fire was expected to reduce soil N pools by volatilisation, but to increase the stable SOC pool by addition of …
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Temperature and physical modelling studies of open windrow composting
… waste material is subject to aerobic exothermic microbial decomposition. Commercial composting operations suffer from the problem that much of the processing is performed using empirical approaches. Improved understanding of the composting process based on scientific methodology is required to …
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Transport and decomposition of allochthonous litter in Icelandic headwater streams: Effects of forest cover
… of litter transport into streams and litter decomposition within them. This was the first study made in Iceland on the terrestrial-aquatic interactions in forested ecosystems. The main study consisted of nine run-off fed headwater streams in Fljótsdalshérað in eastern Iceland (N 65°01’–N …
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Nutrient Cycling in Microdose Fertilized West African Soils Under Indigenous Vegetable Production
… turnover rate of SOM in both ecoregions, with decomposition happening more rapidly in the DS than in the RF. Adsorbed and organic P were the two dominant P species in the manure amended DS soils before planting and after harvest in soils cultivated with both AC and SM, with the addition of urea …
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Dissolved organic carbon and colour dynamics in drained and restored blanket peat
… by an average of 10 cm, enhanced the rate of microbial activity by 33 % and increased DOC and colour production in soil water solutions by 35 %, relative to an adjacent intact site that had not been drained. The greater level of aeration in the upper peat layers associated with a lowered water …
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Novel disturbance regimes in the Arctic: paleoecological perspectives on fire and thermo-erosion from Alaskan tundra
… rapidly increase the carbon pool available for microbial decomposition. On longer timescales, fires can enhance permafrost thaw by reducing surface albedo, enhancing surface roughness, and facilitating shrub expansion and snow drift, which can alter the soil thermal regime. Thus, these novel …
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Nutrient Cycling Between Litters and Soil after Fire in Native Woodland and Pinus radiata Plantations
… after the event. These changes may affect the microbial biomass, nutrient availability and nutrient cycling, and may have flow on effects on soil carbon stocks and cycling. Post-fire effects may also affect success of established (re-sprouting) and recently recruited plants. In particular, …