BE/CBC: The Jasper Ridge Global Change Experiment: Biocomplexity in Ecosystem Responses to Long-Term Environmental Changes

贾斯珀里奇全球变化实验：生态系统对长期环境变化响应的生物复杂性本研究以一年生草地为模式系统，验证了碳、氮、水循环对全球变化响应的四个假说。具体地说，PI将探索如下机制：(1)植物生理和物种动态改变C、N和H2O的循环，(2)C、N和H2O的水平和动态调节植物物种组成，(3)微生物控制短期和长期N的有效性，(4)植物化学组成调节土壤微生物群落的结构和功能。总之，这些假说剖析了连接生物地球化学循环和生态动态的反馈的复杂网络。这项研究建立在贾斯珀里奇全球变化实验的基础设施和正在进行的操作基础上，这是一项多因素、生态系统规模的操作。这些操作是在NSF的支持下于1998年发起的，现在得到了帕卡德基金会的支持。它们包括两个温度水平，两个二氧化碳水平，两个N沉积水平，两个降水水平，以及所有可能的双向、三向和四向组合。该团队包括生物地球化学家、生态生理学家、种群生物学家和微生物生态学家。该项目将探索生物地球化学循环和物种动态之间在一系列时间尺度上的相互作用，从短期的生理变化，到物种组成的变化，历经几代人，再到土壤C和N储量变化的缓慢反馈。实验的大量处理、包含数千个优势植物个体的小区以及关键物种的几代持续时间，为解决关于生物地球化学对现实全球变化的反应的具体问题以及关于主要生物地球化学循环控制的基本问题提供了一个独特的框架。将使用一个模型框架，将生物地球化学、物种变化和物种对生物地球化学的影响结合在一起，以综合整个项目的结果，并将这些结果整合到更广泛的全球变化研究结构中。这项实验旨在作为一个模型系统，其中易于操纵和快速反应可以促进测试机械性假设，并建立一个框架，将潜在的原则推广到其他生态系统。拟议的研究将产生一系列更广泛的影响。Jasper Ridge为由学生和独立资助的研究人员领导的各种项目提供了核心。该项目位于主要城区的大学校园，在斯坦福大学的课堂上非常引人注目，并广泛整合，并为K-12学生和普通公众组织了活动。它是交流全球变化的性质、其影响的多样性以及生物地球化学研究潜力的有效工具。有了这里要求的资金，我们将专注于增加中学生的机会，制定有组织的课程和实习。

ABSTRACTThe Jasper Ridge Global Change Experiment: Biocomplexity in Ecosystem Responses To Long-Term Environmental ChangesThe research proposed here utilizes annual grassland as a model system to test four hypotheses concerning the regulation of the cycles of carbon, nitrogen, and water in response to global change. Specifically, the PIs will explore the mechanisms through which (1) plant physiology and species dynamics alter cycles of C, N, and H2O, (2) levels and dynamics of C, N, and H2O regulate plant species composition, (3) microorganisms control short-term and long-term N availability, and (4) plant chemical composition regulates structure and function of the soil microbial community. Together, these hypotheses dissect the complex web of feedbacks linking biogeochemical cycles and ecological dynamics. The research builds on the infrastructure and ongoing operations of the Jasper Ridge Global Change Experiment, a multi-factor, ecosystem-scale manipulation. The manipulations were initiated in 1998 with NSF support and are now supported by the Packard Foundation. They include two levels of temperature, two of CO2, two of N deposition, and two of precipitation, with single-factor manipulations as well as all of the possible 2-way, 3-way, and 4-way combinations.The team includes biogeochemists, ecophysiologists, population biologists, and microbial ecologists. The project will explore interactions between biogeochemical cycles and species dynamics across a range of time scales, from short-term physiological changes, through changes in species composition that unfold over several generations, to slow feedbacks from changes in soil stocks of C and N. The experiment's large array of treatments, plots that contain thousands of individuals of the dominant plants, and duration of several generations of the key species, provides a unique framework for addressing specific questions about biogeochemical responses to realistic global changes as well as fundamental questions about controls on major biogeochemical cycles. A modeling framework will be used that combines biogeochemistry, species changes, and species effects on biogeochemistry for synthesizing results across the project and integrating those results in the broader fabric of global-change research. This experiment is intended as a model system, where ease of manipulation and rapid responses can facilitate testing mechanistic hypotheses and establishing a framework for generalizing underlying principles to other ecosystems. The proposed research will have a range of broader impacts. Jasper Ridge provides a core for diverse projects led by students as well as independently funded researchers. Located on university campus in a major urban area, the project is highly visible and widely integrated in Stanford classes as well as organized activities for K-12 students and the general public. It is an effective tool for communicating the nature of global changes, the diversity of their impacts, and the potential of biogeochemistry research. With the funding requested here, we will focus on increasing opportunities for secondary students, with an organized curriculum and internships.