Collaborative research: Turning on the lights - Photochemical and microbial processing of newly exposed carbon in arctic ecosystems

合作研究：打开灯——北极生态系统中新暴露碳的光化学和微生物处理

• 批准号: 1022876
• 负责人: George Kling
• 金额: $ 28.77万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1022876&HistoricalAwards=false
• 关键词: Collaborative; research; Turning; lights; Photochemical

This project will investigate the fate of dissolved organic matter (DOM) released in increasing amounts to Arctic surface waters through such disturbances as fire, thermokarst failure, and thawing of permafrost. The investigators hypothesize that newly available soil carbon will be labile to photochemical and microbial attack, and will enhance the degradation of resident DOM in the system resulting in poorer quality DOM exported to the ocean. They plan to develop a mechanistic understanding of these processes by: (A) Determining how fast photochemical reactions and microbial processing will alter resident DOM and the newly-released DOM in surface waters, and (B) Measuring the fate of DOM in surface waters, either as CO2 released to the atmosphere or as organic carbon altered and transported to coastal oceans. This would be accomplished with a series of laboratory experiments to determine rates of photodegradation and microbial processing of DOM from different sources, and a series of landscape comparisons and sampling transects to characterize DOM degradation in small basins and large rivers extending 250-300 km from the headwaters to the Arctic Ocean. By integrating this process-based research with ongoing projects studying the formation of thermokarst failures and the impacts of burning on plant and soil carbon allocation, the investigators will address questions such as whether carbon export from tundra to oceans will rise or fall, how reactive is that exported carbon, and what will be the ultimate impact of impending disturbances, including climate change, on the net carbon balance of the Arctic and its interaction with the global carbon cycle. The investigators will work with several established programs at UNC and UM to (1) recruit women and minority student participation and research in this project specifically from Historically Black Colleges, (2) participate in a workshop on mentoring strategies for minorities, and (3) develop additional outreach activities, including talks to middle and high schools by the PIs, graduate, and undergraduate students. Presentation of data will coordinate with NSIDC and Arctic LTER data management.

该项目将通过诸如火灾，热力学衰竭和永久冻土融化等干扰释放的溶解有机物（DOM）的命运（DOM）的命运。研究人员假设新近可用的土壤碳将不稳定光化学和微生物攻击，并将增强系统中居民DOM的降解，从而导致质量较差的DOM导出到海洋。他们计划通过：（a）确定光化学反应和微生物加工的速度将改变居民DOM和新近发行的DOM，以及（b）测量地表水中的DOM的命运，以便将CO2释放到大气或有机碳变化并运输到沿海海洋中。这将通过一系列实验室实验来确定来自不同来源的DOM的光降解和微生物加工的速率，以及一系列的景观比较和采样样本，以表征小盆地中的DOM降解和大河流中的DOM降解，从而延伸了从床上源到arctic的海洋。通过将这项基于过程的研究与正在进行的项目相结合，研究热力学失败的形成以及燃烧对植物和土壤碳分配的影响，研究人员将解决诸如从苔原到海洋的碳出口到海洋是否会上升或下降，导出的碳的反应性如何，以及在整体上均在包括气候变化的全球范围内的碳平衡和净量的最终影响。调查人员将与（1）招募妇女和少数族裔学生参与和研究该项目的几个既定计划，特别是从历史上的黑人学院参与研究，（2）参加了针对少数群体的指导策略的研讨会，以及（3）开展其他外展活动，包括PIS，研究生，研究生以及学生不足的学生对中学和高中进行对话。数据的呈现将与NSIDC和北极数据管理协调。