Dissertation Research: Changes in Belowground Carbon Dynamics Under Free-Air Carbon Dioxide Enrichment (FACE)

9700830施莱辛格这个项目以北卡罗来纳州中部杜克森林的自由空气二氧化碳浓缩(FACE)实验为中心，旨在阐明土壤碳动态的变化，以响应生态系统级别的大气二氧化碳浓缩。为了实现这一目标，这里提出的研究旨在解决围绕过程层面对土壤功能及其与大气和地下水的联系的理解的问题。将研究碳流入和流出土壤系统的通量，以及土壤剖面内的转移和储存。重要的是，这项研究将利用稳定的碳同位素(C-13)示踪剂的使用，这些示踪剂将随着二氧化碳的浓缩而被引入Face地块的大气中。这种同位素示踪剂将允许检查土壤有机质中碳的结合速度，土壤酸度对风化速度的影响，以及土壤和地下水中长期大气碳汇的可能性。这项研究对全球变化科学家和政策制定者特别感兴趣和重要，他们对“失踪的汇”感兴趣，土壤科学家研究碳动态，地球化学家对生物控制化学风化的程度感兴趣。

9700830 Schlesinger This project, centered around the Free-Air Carbon dioxide Enrichment (FACE) experiment in the Duke Forest of central North Carolina, is designed to elucidate changes in soil carbon dynamics in response to an ecosystem-level atmospheric CO2 enrichment. In reaching this objective, the research proposed here is intended to address questions surrounding process-level understanding of soil function and its link with the atmosphere and groundwater. Fluxes of carbon into and out of the soil system, as well as transfers and storage within the soil profile, will be examined. Importantly, the study will capitalize on the use of stable carbon isotope (C-13) tracers that will be introduced into the atmosphere of the FACE plot with the CO2 enrichment. This isotope tracer will allow the examination of the rate of carbon incorporation into soil organic matter, the effect of soil acidity on weathering rates, and the potential of a long-term atmospheric carbon sink in soils and groundwater. This research is of particular interest and importance to global change scientists and policy-makers interested in the "missing sink", soil scientists examining carbon dynamics, and geochemists interested in the extent of biotic control over chemical weathering.