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）资助的。气候变化导致的水文状况的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，但对这些影响进行实验量化仍然是地球科学家面临的关键挑战。我的研究目标是研究降水增加对铁和有机物生物地球化学循环相互关系的潜在影响。为了实现这一目标，本职业生涯建议的目标是：1)确定含水率增加对亚高山水分梯度沿线腐殖质铁矿物学和化学结构的影响；2)通过详细的实验室研究阐明腐殖质化学结构和浓度对这些水分梯度沿线铁生物矿化的作用；3)揭示水地球化学对矿物中腐殖质空间分布和大分子结构的影响。水界面。该研究方法是综合的，将在科罗拉多州美国农业部FS弗雷泽实验森林沿亚高山水分梯度研究铁矿物的生物地球化学转化、腐殖质结构和铁有机质的相互作用。此外，将沿着水分样带在多个深度插入具有良好特征的铁矿物，以提供有关自然条件下水分对铁生物矿化途径影响的更多信息。利用扫描透射x射线显微镜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)教育和培养具有分析和解决问题能力的未来科学家，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。为了实现这些目标，本CAREER提案的目标是：1)将当今的环境生物地球化学主题以实时格式整合到环境科学课程中；2)启动MEB（指导环境生物地球化学）：一个汇集多学科参与者的本科研究项目，以增加环境科学的多样性，并加强研究生学习的管道。教育方法是开发一套新的课程，将对环境科学课程中反应灵敏的环境生物地球化学主题的需要结合起来，并将进行专业评价和评价。以探究为基础的学习和带有实验室成分的同侪学习对于培养跨学科领域的科学家尤其有价值。MEB的活动还将特别处理妇女和少数群体的代表性问题，侧重于已证明能吸引代表性不足群体的主题。知识价值：了解气候变化对铁的生物地球化学循环的影响是很重要的，因为这可能对污染物和有机碳的命运和运输产生重大影响。事实上，最近得出的结论是，铁矿物是土壤长期有机碳固存的主要控制因素。这项研究挑战了这一结论，因为洪水引起的土壤氧化还原电位的变化可能会导致？碳由于铁的还原性溶解。更广泛的影响：改善对包括环境生物地球化学领域代表性不足的学生、教师和研究人员在内的不同群体的教育和培训，将有助于解决复杂的环境问题。加深对气候对铁的生物地球化学循环的影响的理解，为社会提供了迄今尚未考虑到的潜在的代价高昂的环境问题的知识，这些问题可能导致污染增加，并进一步威胁到全球的水和粮食供应。结果的传播将在四个主要层面上广泛进行：1)在同行评议的期刊上发表文章和在国家和国际会议上发表演讲是明显但重要的传播途径。PI是《环境科学与技术》杂志关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的特邀编辑。2)向高中教师和低年级学生拓展：PI和他的学生将参加K12、搭建桥梁和？科罗拉多州立大学的高中日项目。3)研讨会和国际推广：PI将组织下一届Telluride科学研究中心环境生物地球化学研讨会，并将在德国举办研讨会，讨论基于同步辐射的环境生物地球化学工具。4)合作推广和社区外展：目前与农业实验站一起进行的PI研究为向农业社区传播结果提供了理想的工具。ppi的研究也将通过广播电台和报纸向公众传播。科罗拉多州立大学全球环境可持续发展学院将帮助实现该项目的宏伟目标。