CAREER: Unearthing the Role of Belowground Biology in Biosphere-Atmosphere Volatile Organic Compound (VOC) Exchange

挥发性有机化合物（VOC）通过自然和人为过程排放到大气中，对空气质量和气候起着重要作用。挥发性有机化合物的一个重要自然来源是植物，但了解各自的土壤如何促进挥发性有机化合物的排放仍然是难以捉摸的。这项研究的首要研究目标是挖掘地下VOC循环的微生物过程，描述气候变化如何影响VOC排放。通过合作确保了大气化学和生态系统科学方面的跨学科专业知识，亚利桑那大学拥有必要的基础设施，可进行必要的实地和实验室研究。该计划为学生提供了跨学科学习和从事研究和教育的机会，预计将在五年的项目中直接影响约100名学生。本项目由北京大学大气与地球空间科学系大气化学项目（ATC）和北京大学环境生物学系生态系统科学项目（ES）共同评审和资助，主要研究目标是识别、分离和限制土壤中的挥发性有机化合物代谢，具体包括：（1）识别和整理土壤中驱动挥发性有机化合物代谢的微生物和根系途径;（2）分离地下根-微生物相互作用对土壤中VOC循环的控制作用;（3）从基因到生态系统尺度限制地下VOC循环。在实验室土柱和生物圈2号的实地规模的控制实验中，进行了新的测量挥发性有机化合物的生产和消费的微生物分离物。来自不同数据流的VOC代谢途径被收集在新的微生物挥发组数据库中。为了区分根系来源的贡献，净土壤挥发性有机化合物交换13 C稳定同位素脉冲标记实施与在线13 CVOC测量。最后，新的土壤表面和地下VOC数据收集在一个受控的生态系统干旱实验，推进土壤VOC过程模型和规模地下VOC循环从基因到生态系统。研究结果将有助于理解VOC生物圈-大气交换的地下驱动因素，这将改善对大气影响和VOC生物反馈的预测。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

Volatile organic compounds (VOC) are emitted into the atmosphere through natural and anthropogenic processes and play an important role in air quality and climate. One significant natural source of VOCs is from plants yet understanding how respective soils contribute to VOC emissions remains elusive. The overarching research goal of this study is to unearth microbial processes of VOC cycling below ground that describe how a changing climate may affect VOC emissions. Interdisciplinary expertise in atmospheric chemistry and ecosystem science is secured through collaborations, and necessary infrastructure is available at the University of Arizona to carry out essential field and laboratory studies. This plan provides opportunities for students to learn and engage in research and education across disciplinary boundaries and anticipates to directly impact ~100 students over the five-year project. This project was co-reviewed and co-funded by the Atmospheric Chemistry (ATC) Program in the Division of Atmosphere and Geospace Sciences and the Ecosystem Science (ES) Cluster in the Division of Environmental Biology.Research objectives focus on identifying, separating, and constraining VOC metabolism in soil, and specifically: (1) identifying and collating microbial and root pathways that drive VOC metabolism in soil; (2) separating belowground root-microbe interactions governing VOC cycling in soil; and (3) constraining belowground VOC cycling from gene to ecosystem scales. New measurements of VOC production and consumption by microbial isolates are performed in controlled experiments in laboratory soil columns and at field scale in Biosphere 2. VOC metabolic pathways from diverse data streams are gathered in a new Microbial Volatilome Database. To distinguish root-derived contributions to net soil VOC exchange 13C stable isotope pulse labeling is implemented with online 13CVOC measurements. Finally, new soil surface and subsurface VOC data is collected in a controlled ecosystem drought experiment to advance soil VOC process models and scale belowground VOC cycling from genes to the ecosystem. Results will aid in understanding belowground drivers of VOC biosphere-atmosphere exchange that will improve projections of atmospheric impacts and biological feedbacks of VOCs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.