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

这项研究旨在探讨几种全球变化因素对温带草原生态系统中生态系统过程相互作用的综合影响。生物体、各种化学元素和物理环境之间的复杂相互作用和反馈将使用位于明尼苏达州雪松溪自然历史区的Biocon受控环境设施进行研究，在那里，大气二氧化碳、氮(N)沉积和植物多样性同时受到控制。其目的是确定：(1)在影响群落和生态系统的性质和过程，包括初级生产力、植物组成、碳储量和土壤N动态时，CO2、N的增加和植物多样性的增加对碳-氮循环动态的相互影响；(2)这些相互作用是如何由土壤食物网的微生物互助者、病原体、分解者和其他分类群来调节的。因此，重点明确地放在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碳和氮循环的过程上。Biocon还将加强研究和教育的基础设施，这是一个独特的设施，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。网站上有威斯康星大学教师和本科生研究合作卓越中心的链接，以及北亚利桑那大学环境生物学本科生辅导项目的链接，该项目涉及美国原住民和西班牙裔本科生。最后，高级人员包括四名妇女(包括三名职业生涯初期的科学家)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.