黄海全新世沉积有机质来源和组成变化的多参数指标重建

Due to high terriestrial input, marine primary production and high sedimentation rate, abundant organic matter was buried in the sediments of the Yellow Sea，forming a huge carbon sink.The changes in carbon sink of the Yellow Sea would display an important role on climate change. However, so far, there are few studies about the evolution of bureid organic matter in the Yellow Sea.Especially, to our konwledge, there is not study on long-term quantitative reconstruction for the components and sources of sedimentary organic matter in the Yellow Sea. As a result, the variation rule of sedimentary organic matter in the Yellow Sea is unkonwn and the influnce and feedback of carbon sink in the Yellow Sea on climate change can not be estimated. In this study, multiple proxies and multiple endmember mixing model will be used to subdivide sedimentary organic matter into plant organic matter, soil organic matter and marine organic matter and reconstuct the changes of sedimentary organic matter in the Yellow sea during the Holocene. The results would help to reveal the variation rule of sedimentary organic matter and indicate the major controlling factors on the variation of sedimentary organic matter during the Holocene, which is significant for understanding the relationship between carbon sink effect of the Yellow sea and climate change and the long-term variation mechanism of terrestrial and marine organic matter.

由于高的陆源输入，海洋生产力和高的沉积速率，大量的陆源和海源有机质埋藏在黄海沉积物中，使得黄海成为一个重要的碳汇。黄海碳汇效应的变化对气候变化有重要影响。但到目前为止，黄海埋藏有机质演变的研究很缺乏，尤其是关于长时间尺度沉积有机质组成和来源的定量变化研究还是空白。这就限制了黄海沉积碳汇变化规律的研究，也无法评估黄海沉积碳汇对气候变化的影响和反馈。在此申请中，申请人将利用多参数有机地球化学指标及多元混合模式对黄海沉积有机质全新世以来的变化进行重建，将沉积有机质定量分为陆地植物有机质、土壤有机质和海源有机质三部分，揭示其在全新世的变化特征和规律，讨论控制其在全新世变化的主要因素。研究结果对于揭示黄海碳汇效应及与气候的响应关系，深入了解控制陆源和海源有机质变化的机制有重要意义。

作为重要的碳汇，黄海沉积有机碳的变化对碳循环及气候变化有重要影响。但对黄海埋藏有机质演变的研究还很缺乏，尤其是关于长时间尺度沉积有机质组成和来源的定量研究。针对这一问题，在本项目中我们具体进行了以下研究：1）黄海和渤海表层沉积物样品生物标志物分析及有机地球化学指标的验证，发现在北黄海和渤海C/N和BIT指标不是陆源有机质的良好指标；TEX86在黄海可以指示底层温度。2）基于多参数有机地球化学指标和三元混合模式对黄、渤海沉积有机质进行了定量区分。发现南黄海陆源植被有机质的分布范围比土壤有机质的分布范围更广，含量更高。3）全新世黄海古环境及沉积有机质的变化。对黄海与东海交界处的济州岛泥质区的一个重力柱状样进行了全新世温度重建，发现海平面的变化和冷涡控制了此处全新世环境的变化。对位于山东半岛外缘的黄海泥质区柱样进行了多参数有机地球化学定量重建。结果发现，全新世黄海泥质区有机质组成变化主要与海平面，黄河河口变迁，东亚冬季风及ENSO的增强的变化有关。上述研究结果对理解黄海沉积有机碳变化的规律和机制及碳循环都有重要的意义。