Biogeochemical Processes Governing Production and Emission of Reduced Sulfur Gases along a Salinity Gradient in Gulf Coast Wetlands

德劳恩、帕特里克和林道博士提议对墨西哥湾沿岸湿地的气态硫生产和排放进行实地和实验室研究。关于沿海湿地硫磺气体排放的研究还不够广泛，不足以确定硫磺气体产生的生物地球化学条件和数量。这项研究的地点将是路易斯安那州的巴拉塔里亚盆地。这个盆地包括美国最大、最高产的河口之一，湿地类型从盐沼到淡水沼泽不等。这项研究将量化湿地类型中H_2S和有机硫化合物进入大气的季节和昼夜气体通量。土壤中被捕获的硫磺气体将被测量并与大气排放相关。还将利用实验室中沉积物氧化还原控制的微观世界，研究沉积物氧化还原条件和有机碳在淡水、微咸水和盐沼中形成气态硫形态中的作用。将添加的土壤有机质分解产生的气态硫化物与细菌硫酸盐还原产生的化合物进行比较。湿地植被在气态硫磺生产中的作用也将被调查。德劳恩、帕特里克和林道博士是湿地生物地球化学领域的主要研究人员。这项研究的制度设施非常好。

Drs. DeLaune, Patrick, and Lindau propose to conduct a field and laboratory study of gaseous sulfur production and emissions from Gulf Coast wetlands. Studies of sulfur gas emissions in coastal wetlands have not been extensive enough to establish the biogeochemical conditions and magnitude of sulfur gas production. The site of this study will be Barataria Basin, Louisiana. This basin encompasses one of the largest and most productive estuaries in the United States, with wetland types ranging from salt marsh to fresh marsh. This research will quantify the seasonal and diurnal gaseous fluxes to the atmosphere of H2S and organic sulfur compounds from the wetland types. Sulfur gases trapped in soils will be measured and related to the atmospheric emissions. The role of sediment redox conditions and organic carbon in the formation of gaseous sulfur forms in fresh, brackish, and salt marshes will also be studied using sediment redox controlled microcosms in the laboratory. Gaseous sulfur compounds produced from decomposition of added soil organic matter will be compared to compounds produced from bacterial sulfate reduction. The role of wetland vegetation in production of gaseous sulfur will also be investigated. Drs. DeLaune, Patrick and Lindau are leading researchers in the area of wetland biogeochemistry. The institutional facilities for this research are excellent.