ADVANCE Fellows Award: A Mechanistic Understanding of the Responses of Soil Carbon Pools in Tropical Forests to Increasing Global Temperatures

在J. Powers博士的指导下，研究热带森林土壤碳（土壤C）库对气候变暖的响应机制获得了一项资助。土壤含有世界陆地有机碳的近四分之三，其中28%储存在热带森林土壤中。目前，围绕这个巨大的碳库对全球气温上升的潜在反应存在许多不确定性和争论。科学家们担心，气候变暖可能会加速碳在土壤中的循环过程，导致大量二氧化碳释放到大气中，进一步加速全球变暖。该项目的目标是更好地了解热带土壤C库对全球气温上升的短期和长期反应。这个项目对首席研究员的职业发展起到了重要的作用，使她能够加强自己作为科学家的技能，建立一个独立的研究项目，并继续与当地的小学生进行接触，所有这些都有助于她获得学术界终身职位的目标。这些研究提供了一套完整的实验室实验和模拟练习，以预测热带森林土壤C库对气候变暖的潜在响应，并评估不同机制介导这些响应的程度。将从热带森林科学中心管理的11个大型森林盘查样地的全球网络中取样土壤，以利用正在进行的森林动态、土壤肥力和水文学研究，并反映热带森林所包含条件的多样性。土壤将被置于模拟气候变暖的实验室条件下，并在孵育过程中测量以下响应：二氧化碳流出量、微生物生物量、微生物群落组成和土壤C库大小和结构。实验室结果将通过使用这些数据来参数化土壤C动力学模拟模型来综合。然后，该模型将用于探索在气候变化的情况下，从土壤C库到大气的二氧化碳潜在通量可能有多大。这些研究将为评估储存在热带森林土壤中的重要碳储备如何通过二氧化碳排放与全球气候系统相互作用提供一个基准。这些结果将引起包括热带森林生态学家、土壤和生态系统科学家以及全球建模者在内的广泛科学界的兴趣。此外，这些研究为8-12年级学生和本科生的培训和教育提供了充足的机会。特别是，将以高中生和大学生为对象进行实验研究，并继续开展以8年级学生为对象的科学宣传活动。

AbstractA grant has been awarded under the direction of Dr. J. Powers to investigate the mechanisms that determine the responses of soil carbon (soil C) pools in tropical forests to climate warming. Soils contain nearly three fourths of the world's terrestrial organic carbon, 28% of which is stored in tropical forest soils. There is currently much uncertainty and debate surrounding the potential responses of this large carbon pool to increasing global temperatures. Scientists are concerned that warmer climates may speed up the processes by which carbon is cycled through the soil, resulting in large releases of CO2 to the atmosphere and further accelerating global warming. The goal of this project is to better understand the short- and long-term responses of tropical soil C pools to increasing global temperatures. This project serves an important role in the career development of the principle investigator by allowing her to strengthen her skills as a scientist, establish an independent research program, and continue outreach with local grade school students, all of which facilitate her goal of obtaining a tenure-track position in academia.These studies provide an integrated set of laboratory experiments and modeling exercises to project potential responses of soil C pools from tropical forests to climate warming, and to evaluate the extent to which different mechanisms mediate these responses. Soils will be sampled from a worldwide network of 11 large forest inventory plots administered by the Center for Tropical Forest Science to take advantage of ongoing studies of forest dynamics, soil fertility and hydrology and to represent the diversity of conditions encompassed by tropical forests. The soils will be subjected laboratory conditions that simulate climate warming, and the following responses will be measured over the course of the incubations: CO2 efflux, microbial biomass, microbial community composition, and soil C pool sizes and structure. The laboratory results will be synthesized by using the data to parameterize a simulation model of soil C dynamics. The model will then be used to explore how large the potential fluxes of CO2 from the soil C pool to the atmosphere may be, given climate change. Together these studies will provide a benchmark for evaluating how the important C reserve stored in tropical forest soils may interact with the global climate system through CO2 emissions. These results will be of interest to a broad scientific community including tropical forest ecologists, soil and ecosystem scientists and global modelers. Moreover, these studies provide ample opportunities for training and education of grades 8-12 and undergraduates. In particular, the laboratory research will involve advanced high school students and undergraduates, and an ongoing science outreach program with eighth graders will be continued.