The Carbon Balance of Arctic River Deltas: Tundra Fire as an Agent of System Change

北极河三角洲的碳平衡：苔原火灾作为系统变化的推动者

• 批准号: 1561437
• 负责人: Robert Holmes
• 金额: $ 19.85万
• 依托单位: Woodwell Climate Research Center, Inc.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-11-15 至 2017-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1561437&HistoricalAwards=false
• 关键词: Carbon; Balance; Arctic; River; Deltas

The summer of 2015 was an extraordinary year for fire in the Arctic, including in the Yukon-Kuskokwim Delta, presaging a future where tundra and boreal fire is far more common. Remarkably, the area burned in the YK Delta in 2015 exceeds the total area burned from 1940-2014 combined. The response of the YK Delta in the first year post-fire will set the stage for longer-term changes in delta carbon storage and transport among tundra, aquatic and marine systems, and to the atmosphere. Quantifying carbon export and understanding the immediate ecosystem response to fire is critical because long-term recovery is, to a considerable degree, dependent on short-term responses. A major question that this research will address is how fire influences the amount and form of carbon transported from delta ecosystems seasonally and in the first year following fire. Ultimately, these results will inform long-term trajectories of the vulnerability and fate of delta carbon pools. This research will significantly improve our understanding of the role of fire in the loss of both modern and ancient carbon from arctic river deltas, which contain 10% of the Arctic?s massive permafrost carbon store. This funding will allow project scientists to engage with Alaska Native faculty and students in STEM-focused teacher training programs at the tribal college in Bethel, which will provide teachers with experience conducting research on climate change and arctic system science and the opportunity to develop curriculum focused on climate change and the feedbacks that result from fire and other changes in ecosystems in the Yukon River Delta. This project will also improve the infrastructure for arctic research and teaching at a small Undergraduate Institution in central Minnesota. ]Arctic river deltas are hotspots for carbon storage, occupying 1% of the pan-Arctic watershed but containing 10% of carbon stored in arctic permafrost. They are also heterogeneous mosaics of linked terrestrial and aquatic ecosystems, and are susceptible to changes in land, river, and marine systems. The vulnerability of carbon stored in arctic river deltas is a major unknown and is critically important as climate warming and increasing fire frequency may make this carbon vulnerable to transport to aquatic and marine systems and to the atmosphere. The goal of this proposal is to examine the immediate effects of fire on carbon storage in the Yukon-Kuskokwim Delta and exchange between terrestrial and aquatic components of the Delta. By extension this work will yield critical insights into how the carbon balance of deltas in the arctic system will change over the coming decades as warming continues and fire frequency increases.

2015年夏天是北极火灾的一个不寻常的年份，包括在育空-Kuskokwim三角洲，预示着苔原和北方火灾更加常见的未来。值得注意的是，2015年在YK三角洲燃烧的面积超过了1940-2014年燃烧面积的总和。在火灾后的第一年，YK三角洲的反应将为三角洲碳储存的长期变化奠定基础，并在苔原，水生和海洋系统之间运输，并向大气输送。量化碳输出和了解生态系统对火灾的直接反应至关重要，因为长期恢复在很大程度上取决于短期反应。这项研究将解决的一个主要问题是火灾如何影响从三角洲生态系统运输的碳的数量和形式季节性和火灾后的第一年。最终，这些结果将为三角洲碳库的脆弱性和命运的长期轨迹提供信息。这项研究将大大提高我们对火在北极河流三角洲现代和古代碳损失中的作用的理解，这些三角洲占北极的10%。巨大的永久冻土碳储存。这笔资金将使项目科学家与阿拉斯加原住民教师和学生在伯特利的部落学院从事以STEM为重点的教师培训计划，这将为教师提供开展气候变化和北极系统科学研究的经验，并有机会开发以气候变化为重点的课程，以及由火灾和育空地区三角洲生态系统其他变化引起的反馈。该项目还将改善明尼苏达州中部一个小型本科院校的北极研究和教学基础设施。北极河流三角洲是碳储存的热点，占泛北极流域的1%，但含有10%的北极永久冻土中储存的碳。它们也是联系在一起的陆地和水生生态系统的异质镶嵌体，容易受到陆地、河流和海洋系统变化的影响。储存在北极河流三角洲的碳的脆弱性是一个主要的未知数，这一点至关重要，因为气候变暖和火灾频率增加可能使这些碳容易被输送到水生和海洋系统以及大气中。该提案的目标是研究火灾对育空-Kuskokwim三角洲碳储存的直接影响以及三角洲陆地和水生成分之间的交换。通过扩展，这项工作将产生关键的见解，如何在北极系统三角洲的碳平衡将在未来几十年内变化，随着变暖的继续和火灾频率的增加。