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

摘要碧玉岭全球变化实验：生态系统对长期环境变化响应的生物复杂性本研究利用一年生草地作为模式系统，检验关于碳、氮和水循环响应全球变化的调节的四个假设。具体而言，PI将探索（1）植物生理学和物种动态改变C，N和H2O循环的机制，（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的N可用性，以及（4）植物化学组成调节土壤微生物群落的结构和功能。总之，这些假说剖析了联系地球化学循环和生态动力学的复杂反馈网络。该研究建立在碧玉岭全球变化实验的基础设施和正在进行的操作的基础上，这是一个多因素，生态系统规模的操纵。这些操作于1998年在NSF的支持下启动，现在由Packard基金会支持。它们包括两个温度水平，两个CO2，两个N沉积，两个降水，单因素操作以及所有可能的2-way，3-way和4-way组合。该项目将探索生物地球化学循环和物种动态之间的相互作用，跨越一系列时间尺度，从短期生理变化，通过物种组成的变化，在几代人中展开，从土壤碳和氮储量变化的缓慢反馈。该实验的大量处理，包含数千个个体的优势植物的地块，以及几代关键物种的持续时间，提供了一个独特的框架，用于解决有关地球化学对现实全球变化的反应的具体问题，以及有关控制主要地球化学循环的基本问题。将使用一个模型框架，将地球化学、物种变化和物种对地球化学的影响结合起来，以综合整个项目的结果，并将这些结果纳入更广泛的全球变化研究结构。该实验旨在作为一个模型系统，易于操作和快速反应可以促进测试机制假设，并建立一个框架，将基本原则推广到其他生态系统。拟议的研究将产生广泛的影响。碧玉岭提供了一个由学生以及独立资助的研究人员领导的各种项目的核心。该项目位于一个主要城市地区的大学校园内，非常引人注目，并广泛融入斯坦福大学的课堂以及为K-12学生和公众组织的活动。它是一个有效的工具，沟通全球变化的性质，其影响的多样性，以及地球化学研究的潜力。利用这里要求的资金，我们将侧重于增加中学生的机会，提供有组织的课程和实习机会。

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.