CAREER: Climate Change Impacts on the Interrelationship between Iron Cycling and Organic Carbon: Environmental Biogeochemical Research and Education from Molecular to Field Scale

职业：气候变化对铁循环和有机碳之间相互关系的影响：从分子到现场尺度的环境生物地球化学研究和教育

• 批准号: 0847683
• 负责人: Thomas Borch
• 金额: $ 50万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0847683&HistoricalAwards=false
• 关键词: CAREER; Climate; Change; Impacts; Interrelationship

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Intensification of hydrologic regimes due to climate change will have important impacts on biogeochemical processes and ecosystem services, but quantifying these impacts experimentally remains a key challenge for earth scientists. My research goal is to investigate the potential impacts of increased precipitation on the interrelationship between biogeochemical cycling of iron and organic matter. In pursuit of this goal, the objectives of this CAREER proposal are to: 1) determine the impact of increasing water content on the iron mineralogy and chemical structure of humic substances along subalpine moisture gradients, 2) Elucidate the role of chemical structure and concentration of humic substances on iron biomineralization along these moisture gradients and in detailed laboratory studies, and 3) Reveal the influence of aqueous geochemistry on the spatial distribution and macromolecular structure of humic substances at the mineral?water interface. The research approach is integrative and will investigate biogeochemical transformations of iron minerals, humic substance structures, and iron organic matter interactions along subalpine moisture gradients at the USDA FS Fraser Experimental Forest in Colorado. In addition, well-characterized iron minerals will be inserted into the soil at multiple depths along the moisture transects to provide more information about the impact of moisture on iron biomineralization pathways under natural conditions. Microbial iron reduction and the spatial distribution, macromolecular structure and chemical composition of humic substances at the iron-water interface will be studied for the first time at the nanometer-scale by scanning transmission X-ray microscopy. My long-term educational goals are to: 1) educate and train future scientists with a tool box of analytical and problem solving skills to address the most complex challenges in environmental biogeochemistry, and 2) to get more woman and minorities interested in the field of Earth sciences. In pursuit of these goals, the objectives of this CAREER proposal are to: 1) Integrate today's Environmental Biogeochemistry topics into the environmental science curriculum in a real time format, and 2) Launch MEB (Mentoring Environmental Biogeochemistry): an undergraduate research program that brings together multi-disciplinary participants to increase diversity in environmental science and enhance the pipeline for graduate studies. The educational approach is to develop a set of new courses that integrate the need for responsive environmental biogeochemistry topics in the environmental science curriculum and that will be evaluated and assessed professionally. Inquiry-based learning and peer-learning with a laboratory component will be especially valuable for training of scientists in an interdisciplinary field. MEB activities will also specifically address the need for representation of woman and minorities by focusing on topics that have demonstrated to attract underrepresented groups. Intellectual Merit: It is important that we know the impact of climate change on biogeochemical cycling of iron because this could have significant impact on the fate and transport of pollutants and organic carbon. In fact, it was recently concluded that iron minerals are a major control in long-term organic carbon sequestration in soils. This study challenges that conclusion since a change in soil redox potential due to flooding could potentially lead to a release of ?sequestered? carbon due to reductive dissolution of iron. Broader Impacts: Improved education and training of a diverse group of students, teachers, and researchers including underrepresented in environmental biogeochemistry will help solve complex environmental problems. Advancing the understanding of climate impacts on biogeochemical cycling of iron benefits society by providing knowledge about potential costly environmental problems that have not been considered up to now and that could lead to increased pollution and further threaten the global water and food supply. Dissemination of results will be conducted broadly at four main levels: 1) Publications in peer-reviewed journals and presentations at national and international conferences are obvious but important routes of dissemination. The PI is a guest editor for an Environmental Science & Technology focus issue on Biogeochemical Redox Processes and their Impact on Contaminant Dynamics. 2) Outreach to High School Teachers and Younger Students: The PI and his students will participate in K12, Building Bridges, and ?High School Day programs at CSU. 3) Workshops and International Outreach: The PI will organize the next Telluride Science Research Center workshop on environmental biogeochemistry and will conduct a workshop in Germany discussing synchrotron radiation based tools in environmental biogeochemistry. 4) Cooperative Extension and Community Outreach: Current research of the PI with the agricultural experiment station has provided an ideal vehicle for dissemination of results to the agricultural community. The PIs research will also be communicated to the public via radio stations and news papers. The CSU School of Global Environmental Sustainability will help meet the ambitious goals of this project.

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)提供资金的。气候变化引起的水文变化加剧将对生物地球化学过程和生态系统服务产生重要影响，但在实验上量化这些影响仍然是地球科学家面临的一个关键挑战。我的研究目标是调查降水增加对铁和有机质的生物地球化学循环之间相互关系的潜在影响。为了实现这一目标，本职业建议的目标是：1)确定水分增加对亚高山水分梯度沿线腐殖质的铁矿物学和化学结构的影响，2)阐明沿这些水分梯度的腐殖质的化学结构和浓度对铁生物矿化的作用，并进行详细的实验室研究，以及3)揭示水的地球化学对矿物-水界面腐殖质的空间分布和大分子结构的影响。该研究方法是综合的，将在科罗拉多州的USDA FS Fraser实验森林沿亚高山水分梯度调查铁矿物、腐殖质结构和铁有机质相互作用的生物地球化学转化。此外，将沿着水分横断面在土壤中多个深度插入具有良好特性的铁矿物，以提供更多关于自然条件下水分对铁生物矿化途径的影响的信息。本论文将首次在纳米尺度上研究微生物铁还原和铁-水界面腐殖质的空间分布、大分子结构和化学组成。我的长期教育目标是：1)用分析和解决问题的技能工具箱教育和培训未来的科学家，以应对环境生物地球化学中最复杂的挑战；2)让更多的女性和少数族裔对地球科学领域感兴趣。为了追求这些目标，这份职业计划的目标是：1)以实时的形式将当今的环境生物地理化学主题整合到环境科学课程中，2)启动MEB(导师环境生物地理化学)：这是一个将多学科参与者聚集在一起的本科生研究计划，以增加环境科学的多样性，并加强研究生学习的渠道。教育方法是开发一套新课程，将响应性环境生物地理化学专题的需要纳入环境科学课程，并将进行专业评估和评估。研究性学习和有实验室内容的同行学习对于培养跨学科领域的科学家特别有价值。MEB活动还将具体解决妇女和少数群体代表的需要，重点放在已证明能够吸引代表人数不足的群体的专题。智力价值：重要的是，我们要知道气候变化对铁的生物地球化学循环的影响，因为这可能对污染物和有机碳的去向和迁移产生重大影响。事实上，最近得出的结论是，铁矿物是土壤中长期有机碳固定的主要控制因素。这项研究对这一结论提出了质疑，因为洪水引起的土壤氧化还原电位的变化可能会导致土壤中被隔离的？由于铁的还原溶解而产生的碳。更广泛的影响：改善对不同群体的学生、教师和研究人员的教育和培训，包括在环境生物地球化学领域代表性不足的学生、教师和研究人员，将有助于解决复杂的环境问题。促进对气候对铁的生物地球化学循环的影响的了解有利于社会，因为它提供了关于潜在的代价高昂的环境问题的知识，这些问题迄今尚未得到考虑，可能导致污染加剧，并进一步威胁全球水和粮食供应。将在四个主要层面广泛传播成果：1)在同行评议的期刊上发表出版物以及在国家和国际会议上作专题介绍是显而易见但重要的传播途径。PI是《环境科学与技术》杂志的客座编辑，该杂志聚焦于生物地球化学氧化还原过程及其对污染物动力学的影响。2)对高中教师和年轻学生的外展：PI和他的学生将参加CSU的K12、搭建桥梁和高中日计划。3)讲习班和国际外联：国际和平研究所将组织下一次碲科学研究中心关于环境生物地球化学的讲习班，并将在德国举办一次讲习班，讨论环境生物地球化学中基于同步辐射的工具。4)合作推广和社区推广：目前与农业试验站开展的PI研究为向农业社区传播成果提供了一个理想的工具。调查结果亦会透过电台和报章向公众公布。加州州立大学全球环境可持续发展学院将帮助实现该项目的雄心勃勃的目标。