"Dissertation Research: "Anaerobic ammonium oxidation:a new pathway for N2 losses from humid tropical forest soils?"

“论文研究：“厌氧氨氧化：潮湿热带森林土壤氮损失的新途径？”

• 批准号: 0808383
• 负责人: Whendee Silver
• 金额: --
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0808383&HistoricalAwards=false
• 关键词: Dissertation; Research; Anaerobic; ammonium; oxidation

Denitrification to nitrous oxide (N2O) and dinitrogen (N2) is one of the most poorly understood portions of the land-based nitrogen (N) cycle. This microbial process can release N to the atmosphere as N2O, a potent greenhouse gas and a catalyst for stratospheric ozone depletion, or N2, an inert gas. This dissertation research focuses on understanding the controls on denitrification to N2 and N2O in tropical forest soils, one of the largest natural sources of N2O globally. In preliminary experiments, evidence of N2 production from anaerobic ammonium oxidation (anammox) was detected, as was evidence of iron reduction coupled to anaerobic ammonium oxidation and denitrification. The presence of these new pathways is likely to change the general understanding of ecosystem-scale N cycling. This research will determine the significance of these new N2 production pathways in upland soils. This will be achieved with laboratory experiments employing 15-N tracer methods similar to those successfully used to show the importance of anammox in marine environments. This project will include several science outreach activities in the local community and on the UC-Berkeley campus. These include active contributions to Techbridge Girls, a local program introducing girls to careers in technology, science and engineering, and Community Resources for Science, which helps elementary school teachers use scientific resources for hands-on classroom activities. At UC-Berkeley, project personnel will participate in the Undergraduate Graduate Mentorship Program. Research results will be disseminated at national scientific conferences and incorporated into Ecosystem Ecology lectures on N cycling at UC-Berkeley.

对一氧化二氮（N2O）和二氮（N2）的反硝化是陆基氮（N）循环中最糟糕的部分之一。这种微生物过程可以将n释放到大气中，例如N2O，有效的温室气体和平流层臭氧耗竭的催化剂，或N2，一种惰性气体。 这项论文研究的重点是理解对热带森林土壤中N2和N2O的反硝化的控制，这是全球N2O的最大自然来源之一。在初步实验中，检测到N2产生N2的证据（ANAMMOX），这是铁还原与厌氧铵氧化和非硝化偶联的证据。这些新途径的存在可能会改变对生态系统规模n循环的一般理解。这项研究将确定这些新的N2生产途径在高地土壤中的重要性。这将通过实验室实验采用15-N示踪剂方法来实现，类似于成功用来显示Anammox在海洋环境中的重要性的方法。该项目将包括当地社区和加州大学伯克利分校校园的几项科学外展活动。 其中包括对Techbridge Girls的积极贡献，这是一项本地计划，向女孩介绍技术，科学和工程学的职业以及科学的社区资源，这有助于小学教师使用科学资源来动手进行课堂活动。在加州大学伯克利分校，项目人员将参加本科研究生指导计划。研究结果将在国家科学会议上传播，并将其纳入UC-Berkeley N循环的生态系统生态学演讲中。