RedoxFlux: Biogeochemical fluxes and transformations at pelagic redoxclines in lakes

RedoxFlux：湖泊中上层氧化还原碱的生物地球化学通量和转化

• 批准号: 173813851
• 负责人: Dr. Matthias Koschorreck
• 金额: --
• 依托单位: Department Seenforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/173813851?language=en
• 关键词: RedoxFlux; Biogeochemical; fluxes; transformations; pelagic

The interface between oxic and anoxic water bodies, the redoxcline, separates, or rather connects two very contrasting habitats and is a hotspot of biogeochemical transformations in many lakes. At the depth of the redoxcline, intense cycling of, e.g. sulfur, iron and manganese, occurs. This cycling involves chemical as well as microbial reactions and the corresponding transformation rates are mainly controlled by (i) vertical transport of dissolved and particulate substances, (ii) reaction and precipitation-dissolution kinetics, and (iii) by the availability of light. In this project we will gain a process-based understanding of the interplay of these processes. Vertical fluxes and biogeochemical turnover rates will be estimated in field experiments at three different lakes, representing three contrasting water bodies in terms of the availability of reduced chemical species, light, and vertical mixing. The detailed kinetics of the underlying chemical and microbial reactions will be studied in laboratory mesocosm experiments, set up for two of the study sites. In an innovative approach, the mesocosms will independently mimic density stratification, vertical fluxes of all relevant constituents and vertical mixing. Results from laboratory and field experiments will be combined into a process-based numerical model, allowing for a transfer of our results to different aquatic systems and to changing environmental conditions.

富氧水体和缺氧水体之间的界面，即氧化还原斜，将两个截然不同的栖息地分开，或者更确切地说，连接在一起，是许多湖泊生物地球化学转化的热点。在氧化还原斜的深处，会发生剧烈的循环，例如硫、铁和锰。这种循环涉及化学反应和微生物反应，相应的转化速率主要由以下因素控制：(i)溶解物质和颗粒物质的垂直运输，（ii）反应和沉淀-溶解动力学，以及（iii）光的可用性。在这个项目中，我们将获得对这些过程相互作用的基于过程的理解。垂直通量和生物地球化学周转率将在三个不同湖泊的实地实验中进行估计，这三个湖泊代表三种不同的水体，在减少化学物质、光和垂直混合方面的可用性。将在两个研究地点设置的实验室介观实验中研究潜在化学和微生物反应的详细动力学。在一种创新的方法中，中观将独立模拟密度分层、所有相关成分的垂直通量和垂直混合。实验室和现场实验的结果将结合成一个基于过程的数值模型，允许我们的结果转移到不同的水生系统和不断变化的环境条件。