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

Drs。DeLaune、Patrick和Lindau提议对墨西哥湾沿岸湿地的气态硫产生和排放进行实地和实验室研究。沿海湿地硫气体排放的研究还不够广泛，不足以确定硫气体产生的生物地球化学条件和规模。这项研究的地点将是路易斯安那州的Barataria盆地。这个盆地包括美国最大和最多产的河口之一，湿地类型从盐沼到新鲜沼泽不等。本研究将量化湿地类型中硫化氢和有机硫化合物的季节和日气体通量。将测量土壤中的硫气体，并将其与大气排放联系起来。沉积物氧化还原条件和有机碳在新鲜、微咸和盐沼中形成气态硫形式中的作用也将在实验室中使用沉积物氧化还原控制的微观环境进行研究。由添加的土壤有机质分解产生的气态硫化合物将与细菌硫酸盐还原产生的化合物进行比较。湿地植被在气态硫产生中的作用也将被研究。Drs。DeLaune， Patrick和Lindau是湿地生物地球化学领域的领军人物。进行这项研究的机构设施非常好。

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.