Collaborative Research: Rhizosphere priming and C-N dynamics in grassland ecosystems in transition

合作研究：转型期草原生态系统的根际启动和碳氮动态

• 批准号: 1354920
• 负责人: Gail Wilson
• 金额: $ 12.13万
• 依托单位: Oklahoma State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1354920&HistoricalAwards=false
• 关键词: Collaborative; Research; Rhizosphere; priming; dynamics

Rhizosphere priming, the focus of this study, is the process by which living roots affect the potential for soils to store and release carbon and nitrogen. On a global basis, soils store twice as much carbon as is in the atmosphere and regulate the nitrogen supply to maintain plant productivity while preventing excess nitrogen losses. Laboratory studies indicate that rhizosphere priming is likely a key control on soil CO2 emissions and the release of nitrogen from organic matter. However, the control of rhizosphere priming on soil carbon and nitrogen transformations in real ecosystems has been difficult to study and is not well understood. This is important because many environmental changes could alter rhizosphere priming, with potentially large consequences for carbon storage and nitrogen cycling. By measuring carbon and nitrogen isotope tracers in plants and soils, this study will follow the fate of different carbon and nitrogen sources and separate their contributions the functioning of the soil in grasslands of the central United States. This study also uses plants with different kinds of root characteristics to figure out the different influences plants can have on rhizosphere priming. Over three years, this study will address two main questions: (1) What is the magnitude of rhizosphere priming on the breakdown of organic matter under realistic soil conditions? and (2) How do different plant and soil characteristics affect priming across seasons, types of plants and different soils? This project is that start of a comprehensive effort to decipher and ground truth the important roles of of roots in actual grassland ecosystems.The results of this project will help us understand how changes in plants and environmental conditions affect air quality and the loss of nitrogen from soils. It will train nine undergraduate students, three graduate students, and a post-doctoral scientist. Recruitment of participants will focus on underrepresented groups and build on existing programs in California, Kansas and Oklahoma to increase the diversity of the project participants. Results will be incorporated into undergraduate and graduate courses in the three states and project data will be made available on a web site. This project will also help to enhance public education and awareness and to inform the general public of the importance of roots in providing essential services from our grasslands. Finally, the location and visibility of the experiment at the Konza Prairie Long-Term Ecological Research site in Kansas offers unique opportunities for public education, including development of modules for the schoolyard programs and other outreach activities.

本研究的重点是根系圈启动作用，即活根影响土壤储存和释放碳和氮的潜力的过程。在全球范围内，土壤储存的碳是大气中的两倍，并调节氮的供应，以保持植物的生产力，同时防止过量的氮损失。实验室研究表明，根际引发可能是控制土壤CO2排放和有机质释放氮的关键。然而，在真实的生态系统中，根际引发对土壤碳氮转化的控制一直是难以研究的，也没有得到很好的理解。这一点很重要，因为许多环境变化可能会改变根际引发，对碳储存和氮循环产生潜在的重大影响。通过测量植物和土壤中的碳和氮同位素示踪剂，这项研究将跟踪不同碳和氮源的命运，并将它们对美国中部草原土壤功能的贡献分开。本研究还利用不同根系特征的植物来研究植物对根际引发的不同影响。在三年的时间里，本研究将解决两个主要问题：（1）在实际土壤条件下，根际引发对有机质分解的影响程度如何？（2）不同植物和土壤特性如何影响不同季节、植物类型和不同土壤的引发？这个项目是一个全面努力的开始，以破译和地面真理的重要作用，根在实际的草原生态系统。这个项目的结果将帮助我们了解植物和环境条件的变化如何影响空气质量和氮从土壤中的损失。它将培养9名本科生，3名研究生和一名博士后科学家。参与者的招募将侧重于代表性不足的群体，并以加州、堪萨斯和俄克拉荷马州的现有方案为基础，增加项目参与者的多样性。研究结果将纳入这三个州的本科生和研究生课程，项目数据将在网站上公布。这个项目还将有助于加强公众教育和认识，并使公众了解根在提供草原基本服务方面的重要性。最后，在堪萨斯的康扎草原长期生态研究基地的实验的位置和知名度提供了独特的机会，为公众教育，包括模块的开发校园计划和其他推广活动。