化学结构和矿物对天然有机质稳定性的影响机制

天然有机质（NOM）是生物圈最大的碳库, NOM稳定机制已经成为应对气候变化研究中一个极其活跃的研究领域，也是目前地球化学和土壤学研究的热点问题之一。但是因为NOM的高度复杂性，其稳定机制尚不清楚。本项目拟通过实验室分析和模拟实验，将有机地球化学理论与现代光谱、能谱、核磁共振、同位素分析和热分析等技术手段相结合，来探索矿物和NOM的分子结构分别对不同类型（天然和火成腐殖酸、溶解性有机质和溶解性碳黑）、同一来源、不同地区和不同土壤剖面的NOM 稳定性的影响机制；最终解答关于NOM的稳定性和化学结构之间关系的争议。该项目力图在分子水平上解析NOM的稳定机制，为正确预测NOM随着气候变化所产生的响应提供理论基础，为通过碳封存减缓气候变化的措施提供科学依据。

Natural organic matter (NOM) represents the biggest C pool of the biospheric. Its stabilization mechanisms has been one of the hottest issue in the environmental geochemistry and soil science. Therefore, a clear understanding of NOM stabilization processes is essential to improve predictions of the NOM response to global warming. However, due to the high complexity of NOM, it remains largely unknown why some NOM persists for millennia whereas other NOM decomposes readily.Using combination organic geochemical theory with modern technology including nuclear magnetic resonance (NMR), X-ray photoelectron spectra (XPS), atomic force microscopy (AFM), X-ray absorption near edge fine strture (NEXAFS), scanning transmission X-ray microscopy (STXM), isotopic analysis, this project aims to examine the NOM and minerals characteristics and determine the interactions between mineral and NOM and to explore the role of characteristics of both minerals and NOM in stabilizaiotn of the different NOM factions (natural and pyrogenic humic acids, dissolved organic matter, and dissolved black carbon) isolated from a same source or different horizons of the same soil,and fromthe different kinds soils with the help of the laboratory experiment and simulation; To finally shed a new insight into the long-standing questions about the effect of the chemical structure of the NOM on its stability in the environmental. This project helps to understand the spatial complexity of NOM, the microscope-mechanism of interactions between NOM and minerals, and stabilization mechanisms of NOM from the perspective of molecular levels. It will provide reliable scientific basis for improving predictions of how NOM will respond to climate change as well as mitigating global climate change by sequestering carbon.