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 6 of 6 for “"Diazotrophy"”.
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In the Margins: Reconsidering the Range and Contribution of Diazotrophs in Nearshore Environments
… by generating conditions thought to promote diazotrophy; recent work suggests that broad continental shelf environments may contribute substantially to new reactive N inputs globally. N<sub>2</sub> fixation rates were measured using a robust <sup>15</sup>N tracer method that accounts for the …
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<i>Trichodesmium</i> spp.: Numerical Studies of Resource Competition, Carbohydrate Ballasting, and Remote-Sensing Reflectance
… recent years, a new appreciation for the role of diazotrophy in the oceans has emerged. This dissertation reports on three modeling studies designed to investigate ecological processes associated with <em>Trichodesmium </em>spp., the most conspicuous marine diazotroph: (1) characterization of a …
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Diazotroph Assemblages of Salt Marsh Plants Growing Along An Environmental Gradient: Assemblage Composition and Responses to Environmental Conditions
… productive ecosystems known. Nitrogen fixation (diazotrophy) by the nitrogen-fixing microorganisms in these ecosystems is one of the primary sources of `new' nitrogen and is therefore ecologically significant. The diazotroph assemblages associated with the rhizosphere of <em>S. alterniflora</em> …
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The importance of dissolved organic nutrients in the biogeochemistry of oligotrophic gyres
… central region. Thus no latitudinal gradient in diazotrophy, as suggested by other workers, is apparent. TON and TOP represented not only the major component of the upper ocean N and P pools but were also bioavailable to the community through the release of extracellular enzymes. The cycling of …
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Exploring the Spatial Distribution of Marine Nitrogen Fixation Through Statistical Modeling, High-Resolution Observations and Molecular Level Characterization
… to characterize the biogeography of marine diazotrophy.</p><p>The first approach was to model marine N2 fixation and diazotrophs using machine learning methods. To that end, I conducted meta-analyses to update the global datasets of N2 fixation and diazotrophs. The number of observations in …
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Impacts of Microenvironment On Distributions and Activities of Bacteria In A Salt Marsh Environment
<p>Infaunal burrows and the rhizosphere of Spartina alterniflora are ecologically relevant microenvironments that impact the distributions of bacteria in a salt marsh ecosystem. Infaunal burrows produced by the fiddler crabs Uca pugilator and Uca pugnax are abundant features of southeastern United …