The Controls of Sulfur Storage in Lake Sediments by Interactions among the Carbon, Iron, Oxygen and Sulfur Cycles

世界上许多地区的湖泊现在都收到相当多的 硫酸盐的输入来自酸沉降。 吉布林、彼得森和 弗莱先前专注于地球化学的变化， 由于硫酸盐负荷增加， 他们的工作揭示了 关于硫如何循环的一些现有范式 湖泊的功能可能需要修改。调查人员现在 从实验室培养物和沉积物中 碳限制了一些湖泊中硫酸盐的还原。在 在这项建议中，调查人员重点关注了几个问题， 是他们之前工作的直接成果 问题：1）如何 湖泊硫储量的碳限制是普遍存在的 沉淀物？2)富营养化是如何影响 湖泊沉积物中储存的硫的形式？3)铁 有效性影响许多湖泊沉积物中硫的储存？ 研究人员提出了一个多方面的实验 包括沉积物元素测量的方法 各种湖泊的剖面，整体代谢研究 湖的水平，和变量的实验操作， 现场和实验室设置。 这种平衡的方法应 允许关于C、N、Fe和P的响应的可靠结论 循环到硫酸盐负荷的变化，以及这些反应是如何 因富营养化而改变。 这项研究由一个高素质的团队进行 从一个杰出的机构。 这项工作的结果将 提供重要的知识，以了解的反应， 湖泊富营养化和酸雨。

Lakes in many areas of the world now receive considerable inputs of sulfate from acid deposition. Giblin, Peterson, and Fry previously focused on the biogeochemical changes that occur in lakes due to increased sulfate loading. Their work revealed that some of the existing paradigms on how the sulfur cycle in lakes functions may need to be modified. The investigators now have evidence from both laboratory incubations and sediment profiles that carbon limits sulfate reduction in some lakes. in this proposal the investigators focus on several questions that are a direct outgrowth of their previous work. These are: 1) How widespread is carbon limitation of sulfur storage in lake sediments? 2) How does eutrophication influence the amounts and forms of sulfur stored in lake sediments? 3) Does iron availability effect sulfur storage in sediments in many lakes? The investigators propose a multifaceted experimental approach that includes the measurement of sediment element profiles from a variety of lakes, metabolic studies at the whole lake level, and the experimental manipulation of variables in field and laboratory settings. This balanced approach should allow robust conclusions about responses of the C,N,Fe, and P cycles to changes in sulfate loading, and how these responses are altered by eutrophication. This research is being conducted by a highly qualified team from an outstanding institution. The results of this work will provide important knowledge for understanding the responses of lakes to eutrophication and acid precipitation.