Response of belowground carbon, sulphur and iron cycling in fen soils

沼泽土壤地下碳、硫、铁循环的响应

• 批准号: 5445005
• 负责人: Professor Dr. Christian Blodau (†)
• 金额: --
• 依托单位: Arbeitsgruppe Ökohydrologie und Stoffkreisläufe
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5445005?language=en
• 关键词: Response; belowground; carbon; sulphur; iron

Climate models predict increases in summer drought and intensive rainfalls in temperate and northern latitudes, which may alter the hydrologic and redox regime of wetlands, the single most important terrestrial carbon storage. The impact of drying and rewetting and potential inundation on ecosystem production and belowground carbon cycling and the coupling with redox processes, in particular of sulfur and iron, is not well understood to date. In this project the hydrologic regime of a wetland will be altered experimentally and the consequences on carbon cycling be analyzed and simulated. To this end, changes in soil water contents, temperatures and respiration rates will be quantified during and after manipulation. The availability, production, and consumption of relevant electron acceptors for respiration, i.e. oxygen, nitrate, sulfate, ferric iron, humic substances, is studied, as their dynamics strongly influences methane production. A laboratory study will serve to analyze the impact of a range of temperatures and drying intensity and duration on respiration. The obtained data will be combined with the data of the previous controlled mesocosm and field study to simulate the impact of hydrologic change on carbon cycling and methane dynamics using the ecosystem model ECOSYS. The parameterized and tested model will be used to simulate and analyze the interaction of biogeochemical processes occurring during drying and rewetting and the impact on carbon cycling on the decadal time scale.

气候模型预测，温带和北纬地区夏季干旱和强降雨增加，这可能会改变湿地的水文和氧化还原状况，湿地是最重要的陆地碳储存。干燥和复湿以及潜在的淹没对生态系统生产和地下碳循环的影响，以及与氧化还原过程的耦合，特别是硫和铁的影响，迄今还没有很好的了解。在这个项目中，将通过实验改变湿地的水文状况，并对其对碳循环的影响进行分析和模拟。为此，将量化操作过程中和操作后土壤水分含量、温度和呼吸速率的变化。研究了与呼吸作用相关的电子受体，即氧、硝酸盐、硫酸盐、铁、腐殖质的有效性、产生和消耗，因为它们的动态对甲烷的产生有很大的影响。一项实验室研究将用于分析一系列温度以及干燥强度和持续时间对呼吸的影响。所获得的数据将与以前的受控中观系统和实地研究的数据相结合，利用生态系统模型生态系统来模拟水文变化对碳循环和甲烷动力学的影响。该模型将用于在十年尺度上模拟和分析干湿过程中生物地球化学过程的相互作用及其对碳循环的影响。