The Carbon Balance of Arctic Tundra in Response to Permafrost Thawing: Using Radiocarbon to Detect the Loss of Old Soil Carbon

北极苔原对永久冻土融化的碳平衡：利用放射性碳检测旧土壤碳的损失

• 批准号: 0516326
• 负责人: Edward Schuur
• 金额: --
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0516326&HistoricalAwards=false
• 关键词: Carbon; Balance; Arctic; Tundra; Response

ABSTRACTUp to 450 billion tons of soil carbon has accumulated in high latitude ecosystems after theretreat of the last major ice sheets. Recent studies suggest that these ecosystems may no longerbe accumulating carbon in soils, and in some cases may be losing stored carbon to theatmosphere. This study will use measurements of radiocarbon isotopes to ask the question: Is oldcarbon that comprises the bulk of the soil organic matter pool released in response to thawing ofpermafrost? Field measurements will center on a site in Alaska where permafrost has beenobserved to warm and melt over the past several decades. This area is unique for addressingquestions at the time scales relevant for change in arctic ecosystems.This project has broad significance for changes in the global carbon cycle. Transfer of carbonnow stored in waterlogged and frozen soils to the atmosphere could cause a significant positivefeedback to climate change due to the large size and potential reactivity of this carbon reservoir.In addition to the measurement program, this project will support an experienced journalist tospend time in the field each year as a consultant to the project. She will interface with scientistsand communicate the results of the research by producing stories for various public radio andprint outlets. These stories will share the research questions and implications of this project witha broad-based, lay audience.

摘要在最后一次大冰原消融后，高纬度生态系统累积了高达4500亿吨的土壤碳。最近的研究表明，这些生态系统可能不再在土壤中积累碳，在某些情况下，可能会将储存的碳流失到大气中。这项研究将使用放射性碳同位素的测量来提出这样一个问题：构成大部分土壤有机质库的旧碳是由于永久冻土融化而释放的吗？实地测量将集中在阿拉斯加的一个地点，在过去的几十年里，那里的永久冻土被观察到变暖和融化。这个领域在解决与北极生态系统变化有关的时间尺度问题方面是独一无二的。该项目对全球碳循环变化具有广泛意义。由于这种碳库的巨大规模和潜在的反应性，将储存在涝冻土壤中的碳转移到大气中可能会对气候变化产生显著的正反馈。除了测量项目外，该项目还将支持一名经验丰富的记者每年在该领域作为项目顾问。她将与科学家交流，并通过为各种公共广播和印刷媒体制作故事来传达研究结果。这些故事将与基础广泛的外行观众分享这个项目的研究问题和影响。