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 14 of 14 for “"Organic matter cycling"”.
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Investigating dissolved organic matter cycling in High Arctic ponds and soils
As the most bioavailable fraction of organic matter, dissolved organic matter (DOM) plays an important role in the carbon (C) cycle. Heterotrophic microorganisms degrade DOM and release it to the atmosphere as carbon dioxide (CO2) under oxygenated conditions. However, some DOM may be more readily …
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Consequences of nutrient enrichment for soil organic matter cycling in grasslands
… 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 changes to grassland soil C sequestration could feed back to influence the global C cycle. Unfortunately, the …
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Linking microbial metabolism and organic matter cycling through metabolite distributions in the ocean
… microbes that fix, remineralize, and transform organic matter. Many of the small organic molecules in the marine carbon pool have not been well characterized and their roles in microbial physiology, ecological interactions, and carbon cycling remain largely unknown. In this dissertation …
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Linking microbial metabolism and organic matter cycling through metabolite distributions in the ocean
… microbes that fix, remineralize, and transform organic matter. Many of the small organic molecules in the marine carbon pool have not been well characterized and their roles in microbial physiology, ecological interactions, and carbon cycling remain largely unknown. In this dissertation …
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Soil-derived dissolved organic matter cycling at terrestrial-aquatic interfaces: Implications for wetland-dominated landscapes, stormwater control measures, and drinking water supply
… such as carbon and nutrients. Dissolved organic matter (DOM) is a soluble and reactive form of carbon comprised of organic molecules derived from allochthonous (e.g., soils, plants) and autochthonous (e.g., algae, microbes) sources. Soils are source of DOM found at TAIs. However, …
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Radium isotopes and radon-222 as tracers of sediment-water interaction in Arctic coastal and lacustrine environments
… nutrient consumption and regeneration, organic matter leaching and degradation, and mineral weathering. Radium isotopes (²²³Ra, ²²⁴Ra, ²²⁶Ra, ²²⁸Ra) and radon-222, naturally occurring radioactive isotopes produced in sediments, are well-suited as tracers of nutrients, trace metals, and …
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Radium isotopes and radon-222 as tracers of sediment-water interaction in Arctic coastal and lacustrine environments
… nutrient consumption and regeneration, organic matter leaching and degradation, and mineral weathering. Radium isotopes (223Ra, 224Ra, 226Ra, 228Ra) and radon-222, naturally occurring radioactive isotopes produced in sediments, are well-suited as tracers of nutrients, trace metals, and …
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The large scale understanding of natural organic matter : processes and application
… several barriers to understanding natural organic matter cycling across terrestrial and aquatic ecosystems. Soil organic matter (SOM) turnover models are often constrained by C and N, while data on organic P is lacking. Twenty UK soils were used to provide the first investigation of organic …
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Effects of Western Spruce Budworm Herbivory on Forest Soils and Litter Decomposition in Central Washington
<p>Disturbances by herbivores can drive nutrient cycling in forest ecosystems by adding frass, carcasses, and molts to the forest floor which are broken down into nitrogen, phosphorous, and other elements to be recycled into biomass. Western spruce budworms are defoliators native to the central …
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Compositional heterogeneity within oceanic POM : a study using flow cytometry and mass spectrometry
… statistics to the study of marine particulate organic matter (POM) collected from the North Atlantic. DT-MS is an important asset to marine organic geochemistry as a single two minute analysis (with 16 eV, EI+ ionization) provides information on polysaccharides, proteins, and lipids within …
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Tannin geochemistry of natural systems: method development and application
… tissues---all major contributors to terrigenous organic matter cycling in aquatic systems. However, virtually nothing is known at the molecular level about tannin diagenesis despite the increased sensitivity and unambiguity of molecular characterizations vs. bulk techniques. Due to the analytical …
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Microbial Degradability of Terrigenous, Marsh-Exported, and Estuarine Colored Dissolved Organic Matter in Long Island Sound
… increased biological productivity. Dissolved organic matter (DOM) is a sensitive indicator of anthropogenic pollution and nutrient enrichment in coastal waters as well as an important part of the carbon cycle and serves as a primary food source for aquatic food webs. Additionally, the colored …
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Linking Carbon Dynamics in Stream Ecosystems to Dissolved Organic Matter Quality
… form of CO2 from groundwater, streams receive organic matter from aquatic and terrestrial origins which is partly mineralized to inorganic nutrients and CO2. Future predictions suggest enhanced input of terrestrial organic matter into streams. As such, surrounding land use may highly influence …
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Oxygen Isotopes as a Tracer of DOM Processes in River-Estuary Systems
<p>In the biogeochemical study of dissolved organic matter (DOM) in natural waters, stable isotopes are used to provide insight into both the sources of DOM and the processes affecting its alteration. Through the research presented here, oxygen isotopes are incorporated into the study of DOM …