Interacting Responses of C and N Cycles to Altered Biodiversity, Elevated CO2, and N Enrichment

本研究旨在探讨温带草原生态系统中多个全球变化因子对生态系统过程相互作用的综合影响。生物、各种化学元素和物理环境之间复杂的相互作用和反馈将使用BioCON控制的环境设施进行研究，该设施位于明尼苏达州雪松溪自然历史区，同时控制大气二氧化碳、氮(N)沉积和植物多样性。研究的目的是确定：(1)CO2升高、N富集和植物多样性对碳氮耦合循环动态的相互作用，因为它们影响群落和生态系统的特性和过程，包括初级生产力、植物组成、碳储量和土壤N动态；(2)微生物共生菌、病原体、分解者和土壤食物网的其他分类群如何介导这些相互作用。因此，重点是植物和微生物生物多样性之间的相互作用以及影响生态系统C和N循环的过程。拟议研究的更广泛影响包括这样一个事实，即这将解决有关人类活动对地方到全球尺度的环境过程的潜在影响的社会重大问题。BioCON还将加强研究和教育的基础设施，代表一个独特的设施，向感兴趣的科学家和学生开放并鼓励他们提出新的倡议。学生将来自各个层次，本科生，研究生和博士后研究人员，包括本科生暑期实习。威斯康星大学的教师和本科生研究合作卓越中心以及北亚利桑那大学的环境生物学本科生指导项目都有链接，该项目涉及美国原住民和西班牙裔本科生。该项目还将通过Cedar Creek LTER校园项目与当地公立学校建立合作关系，并为之做出贡献。最后，高级人员包括四名女性（包括三名早期职业科学家）和一名少数民族。

The proposed research addresses the integrated effects of several global change factors on interactions among ecosystem processes in a temperate grassland ecosystem. The complex interactions and feedbacks among organisms, various chemical elements and the physical environment will be studied using the BioCON controlled environment facility at the Cedar Creek Natural History Area, Minnesota, where atmospheric CO2, nitrogen (N) deposition, and plant diversity are simultaneously manipulated. The are to determine: (1) the interacting effects of elevated CO2, N enrichment, and plant diversity on the dynamics of coupled carbon-nitrogen cycles as they influence community and ecosystem properties and processes, including primary productivity, plant composition, carbon storage, and soil N dynamics; and (2) how these interactions are mediated by microbial mutualists, pathogens, decomposers, and other taxa of the soil food web. Hence the focus is explicitly on the interactions between plant and microbial biodiversity and processes that influence ecosystem C and N cycling. The broader impacts of the proposed research include the fact that this will address issues of major importance to society regarding the potential impacts of human activities on environmental processes at local to global scales. BioCON will also enhance the infrastructure for research and education, representing a unique facility open to and encouraging new initiatives from interested scientists and students. Students will be from all levels, undergraduate, graduate student, and postdoctoral researchers and includes undergraduates summer internships. There are links to the University of Wisconsin's Center of Excellence for Faculty and Undergraduate Student Research Collaboration and the Undergraduate Mentoring in Environmental Biology Program at Northern Arizona University that involves Native American and Hispanic undergraduates. The project also will both build on and contribute to ongoingpartnerships with local public schools through the Cedar Creek LTER Schoolyard program. Finally, the senior personnel include four women (including three early-career scientists) and one minority.