Collaborative Proposal: Distribution and Dynamics of Belowground Carbon in Savannas

该项目将在博茨瓦纳喀拉哈里沙漠跨越区域气候梯度的地点绘制根系和土壤碳的三维地图。喀拉哈里沙漠是地球上唯一一个可以进行这种自然实验而不必担心土壤特征变化问题的地方。本研究旨在了解1)根系在土壤中的分布如何在不同植物物种和长距离之间变化；2)土壤中碳含量如何在多个时间尺度上响应气候变化。干旱和半干旱地区，如喀拉哈里沙漠，覆盖了地球陆地表面的40%以上。根系是这些生态系统生产力和组成的重要组成部分，在应对气候变率方面发挥着重要作用。因此，了解限水植被的根系结构对全球生物圈的研究至关重要。其中包括人类居民？以及气候变化中的全球碳预算。本研究将探讨有限水生态系统中地下植物过程如何在不同气候条件下控制地下碳动态。这项研究的跨学科性质将包括指导来自博茨瓦纳和美国的研究生和本科生，并与博茨瓦纳的同事合作。将为高中科学教师开设一门有关研究和相关领域的短期课程，以鼓励在高中课堂上讨论植物与水的相互作用和积极的研究。

This project will map root and soil carbon in three dimensions at sites across a regional climate gradient in the Kalahari Desert of Botswana. The Kalahari is one of the only places on Earth where this type of natural experiment can be conducted without having to worry about problems of variations in soil characteristics. This research seeks to understand 1) how the distribution of roots in the soil varies among different plant species and across large distances, and 2) how carbon found in soils changes in response to climate change at multiple timescales.Arid and semiarid regions, such as the Kalahari, cover over 40% of the Earth's land surface. Roots are an important component of the productivity and composition of these ecosystems, and play an important role in their response to climate variability. Thus, understanding the root structure of water-limited vegetation is vital to the study of the global biosphere?which includes its human inhabitant?and global carbon budgets amidst a changing climate. This research will address how belowground plant processes in water-limited ecosystems control belowground carbon dynamics under different climate conditions. The interdisciplinary nature of this research will include mentoring of graduate and undergraduate students from Botswana and the U.S., and collaborations with colleagues in Botswana. A short course on the research and related fields will be offered to high-school science teachers to encourage the discussion of plant-water interactions and active research in high school classrooms.