"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.

反硝化为一氧化二氮 (N2O) 和二氮 (N2) 是陆地氮 (N) 循环中人们最了解的部分之一。这种微生物过程可以将氮以 N2O（一种强效温室气体）或 N2（一种惰性气体）的形式释放到大气中，N2O 是一种强效温室气体，也是平流层臭氧消耗的催化剂。 本论文研究的重点是了解热带森林土壤中 N2 和 N2O 反硝化的控制，热带森林土壤是全球 N2O 最大的天然来源之一。在初步实验中，检测到厌氧氨氧化（anammox）产生 N2 的证据，以及厌氧氨氧化和反硝化过程中铁还原的证据。这些新途径的存在可能会改变对生态系统规模氮循环的一般理解。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。这将通过采用 15-N 示踪剂方法的实验室实验来实现，该方法类似于成功用于显示厌氧氨氧化在海洋环境中的重要性的方法。该项目将包括在当地社区和加州大学伯克利分校校园进行的多项科学推广活动。 其中包括对 Techbridge Girls 的积极贡献，这是一个向女孩介绍技术、科学和工程职业的当地计划，以及科学社区资源，帮助小学教师利用科学资源进行课堂实践活动。在加州大学伯克利分校，项目人员将参加本科生导师计划。研究结果将在全国科学会议上传播，并纳入加州大学伯克利分校关于氮循环的生态系统生态学讲座。