CAREER: The Role of Iron and Reactive Oxygen Species in the Oxidation and Fate of DOM in Natural Waters

职业：铁和活性氧在天然水中 DOM 的氧化和归宿中的作用

• 批准号: 1351745
• 负责人: Rose Cory
• 金额: $ 59.57万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1351745&HistoricalAwards=false
• 关键词: CAREER; Role; Iron; Reactive; Oxygen

Title: The role of iron and reactive oxygen species in the oxidation and fate of DOM in natural waters This study will determine the direct and indirect roles of iron in both light and dark reactions involving DOM degradation, and estimate the importance of iron in determining whether this degradation will shunt C as DOM down rivers to oceans, or fully oxidize C to CO2 released to the atmosphere. The proposed work will advance our understanding of the degradation of soil carbon exposed to oxygen or sunlight at Earth?s surface during land-surface disturbances. This knowledge will allow scientists to better predict the fate of C in arctic permafrost soils, and through an education and outreach plan, will allow society to better prepare for the potential acceleration of global warming through a positive feedback from the thawing Arctic. To engage underrepresented students in science, the PI proposes to expand the infrastructure of education through partnerships that will offer new opportunities to enhance teaching and communication skills. The PI will develop a curriculum in earth and environmental science integrated with her research, grounded in core education principles, and mapped to assessment goals. A novel contribution to curriculum development will be the combination of (1) education modules that ?telescope? in age-context and difficulty from K-12 to undergraduate to adult outreach levels, (2) data generation on student engagement and learning through micro-assessments of performance, and (3) enhanced active learning by iterative improvement of modules by students for their own peer groups. This research will be done in the Alaskan Arctic because (1) the lakes, streams, and soil waters provide a natural experimental matrix of both high and low light, oxygen, DOM and Fe concentrations, and (2) there are tremendous stores of organic C in frozen soils (at least twice the amount of C now in the atmosphere) which are rapidly thawing from global warming. Using field surveys and experiments on natural waters to test mechanistic hypotheses, the PI will answer two main research questions: (1) Do reactions mediated by iron favor the complete oxidation of DOM to CO2 by sunlight and microbes? (2) Is the iron-mediated oxidation of DOM in the dark an important determinant of DOM fate?

标题：铁和活性氧在天然水中 DOM 的氧化和归宿中的作用这项研究将确定铁在涉及 DOM 降解的光反应和暗反应中的直接和间接作用，并估计铁在确定是否这种降解会将碳作为 DOM 分流到河流中进入海洋，或者将碳完全氧化为二氧化碳释放到大气中。拟议的工作将增进我们对地表扰动期间暴露在地球表面氧气或阳光下的土壤碳退化的理解。这些知识将使科学家能够更好地预测北极永久冻土中碳的命运，并通过教育和推广计划，使社会能够通过北极融化的积极反馈，更好地为全球变暖的潜在加速做好准备。为了让代表性不足的学生参与科学，PI 建议通过合作伙伴关系扩大教育基础设施，这将为提高教学和沟通技能提供新的机会。 PI 将结合她的研究开发地球和环境科学课程，以核心教育原则为基础，并映射到评估目标。对课程开发的一项新颖贡献将是（1）“望远镜”教育模块的组合。从 K-12 到本科生到成人外展水平的年龄背景和难度，(2) 通过绩效微观评估生成有关学生参与和学习的数据，以及 (3) 通过学生迭代改进模块来增强主动学习自己的同侪群体。这项研究将在阿拉斯加北极地区进行，因为 (1) 湖泊、溪流和土壤水提供了强光和弱光、氧气、DOM 和 Fe 浓度的自然实验基质，(2) 有机质储量巨大。冻土中的碳（至少是现在大气中碳含量的两倍），由于全球变暖而迅速融化。通过对天然水体的实地调查和实验来检验机制假设，PI 将回答两个主要研究问题：（1）铁介导的反应是否有利于阳光和微生物将 DOM 完全氧化为 CO2？ (2) 黑暗中铁介导的 DOM 氧化是 DOM 命运的重要决定因素吗？