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Biogeochemistry Of Microbial Mats From A Hypersaline Pond And Reef Biofilm From A Modern Coral Reef, The Bahamas, Mary Keith Puckett
Biogeochemistry Of Microbial Mats From A Hypersaline Pond And Reef Biofilm From A Modern Coral Reef, The Bahamas, Mary Keith Puckett
Theses and Dissertations
Biofilm communities host complex biogeochemical processes and play a role in the formation of many carbonate rocks by influencing both carbonate precipitation and dissolution. In this study, the biogeochemistry of microbial mats from a hypersaline pond and biofilm from a coral reef are described using SEM, microelectrode profiling, Biolog, fatty acid methyl ester (FAME) and carbon nitrogen analysis. Results show that the microbial mats are distinctly layered, having an oxic upper portion and an H2S-rich lower portion. The most significant conclusions are that the mats have exceptionally high TOC values and display significant differences in microbial communities present, both between …
Consequences Of Vegetation Change On The Dynamics Of Labile Organic Matter And Soil Nitrogen Cycling In A Semiarid Ecosystem, Toby D. Hooker
Consequences Of Vegetation Change On The Dynamics Of Labile Organic Matter And Soil Nitrogen Cycling In A Semiarid Ecosystem, Toby D. Hooker
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Sagebrush-dominated ecosystems are being transformed by wildfire, rangeland improvement techniques, and exotic plant invasions. These disturbances have substantial effects on the composition and structure of native vegetation, but the effects on ecosystem C and N dynamics are poorly understood. To examine whether differences in dominant vegetation affect the quantity and quality of plant organic matter inputs to soil, ecosystem C and N pools and rates of plant turnover were compared among historically grazed Wyoming big sagebrush, introduced perennial crested wheatgrass, and invasive annual cheatgrass communities. Since low soil moisture during the summer may inhibit the microbial colonization of plant detrital …
Distribution, Diversity And Ecology Of Aerobic Carbon Monoxide-Oxidizing Bacteria In Hawaiian Volcanic Deposits, Carolyn Frances Weber
Distribution, Diversity And Ecology Of Aerobic Carbon Monoxide-Oxidizing Bacteria In Hawaiian Volcanic Deposits, Carolyn Frances Weber
LSU Doctoral Dissertations
Carbon monoxide-oxidizing bacteria are among the first colonists of recently formed volcanic deposits despite environmental conditions that challenge their survival, such as oscillating water regimes and lack of endogenous sources of organic carbon and nitrogen. Activity assessments and molecular surveys of the coxL gene (large subunit carbon monoxide dehydrogenase) across a vegetation gradient on a 1959 volcanic deposit on Kilauea Volcano (Hawai’i) indicated that CO-oxidizing communities continue to expand, diversify and remain competitive during ecosystem development. Distinct compositional shifts occurred across the gradient with Firmicutes-like coxL sequences dominating clone libraries from unvegetated sites (Bare) and Proteobacteria coxL sequences dominating libraries …