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

该项目围绕北卡罗莱纳州中部杜克森林的自由空气二氧化碳富集（FACE）实验展开，旨在阐明生态系统水平大气二氧化碳富集对土壤碳动态变化的响应。为了达到这一目标，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。将研究进出土壤系统的碳通量，以及土壤剖面内的转移和储存。重要的是，该研究将利用稳定碳同位素（C-13）示踪剂的使用，该示踪剂将被引入二氧化碳富集的FACE地块的大气中。这种同位素示踪剂将使我们能够研究碳进入土壤有机质的速率、土壤酸度对风化速率的影响以及土壤和地下水中长期大气碳汇的潜力。这项研究对全球变化科学家和对“缺失汇”感兴趣的政策制定者、研究碳动态的土壤科学家以及对生物控制化学风化程度感兴趣的地球化学家来说特别感兴趣和重要。

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.