黄河下游-河口-邻近海域表层沉积物中木质素的特征及其示踪意义

发布时间：2018-06-15 03:31

本文选题：黄河河口 + 木质素　；参考：《海洋科学》2016年02期

【摘要】：河流输入的陆源有机碳在河口和陆架区的生物地球化学过程是全球碳循环的重要环节,对陆源有机质的输入量的估算是研究陆架区的生物地球化学过程的基础。黄河输沙量极大,为探究其携带的陆源有机质对陆架边缘海有机碳库的影响,以黄河河口及邻近渤海海域为研究对象,分析了表层沉积物中的木质素,结合总有机碳含量、总氮含量和有机碳稳定同位素评估了表层沉积物中有机碳的组成、来源和分布。8种木质素酚单体中,紫丁香基酚类(S)与香草基酚类(V)的含量比值S/V(0.63±0.31)和肉桂基酚类(C)与香草基酚类含量比值C/V(0.25±0.15),反映出研究区陆源有机碳主要来自草本被子植物。V系列中木质素酸(Ad)与木质素醛(Al)的比值(Ad/Al)V较高(0.53±0.14),表明陆源有机质的降解程度较高。利用稳定碳同位素比值δ13C和木质素含量Λ8相结合的土壤有机质-陆生维管植物-水生有机质三端元模型对陆源有机物的贡献的分析结果显示,土壤有机质、陆源维管植物和水生有机质的平均贡献分别为59.9%±15.0%、7.3%±7.0%、32.8%±11.8%。土壤在陆源有机质中的贡献占有绝对优势,可能与该区域沉积物的主要源区——黄土高原植被覆盖率低、土壤侵蚀严重有关。
[Abstract]:The biogeochemical process of terrestrial organic carbon input from rivers in estuaries and continental shelf areas is an important part of the global carbon cycle. The estimation of the input amount of terrestrial organic matter is the basis of studying the biogeochemical process in continental shelf areas. The Yellow River has a great amount of sediment transport. In order to study the influence of the organic matter carried by the Yellow River on the organic carbon pool in the marginal sea of the continental shelf, the lignin in the surface sediments and the total organic carbon content are analyzed by taking the Yellow River estuary and the adjacent Bohai Sea as the research objects. Total nitrogen content and organic carbon stable isotopes were used to evaluate the composition, source and distribution of organic carbon in surface sediments. The ratio of S / V (0.63 卤0.31) and C / V ~ (0.25 卤0.15) to C / V ~ (0. 15) / S / V) and C / V) to V) respectively, indicating that the terrestrial organic carbon in the study area is mainly derived from the lignin acid adon of the herb angiosperm. V series) and the wood content ratio of C / V = 0. 25 卤0. 15%, indicating that the main sources of organic carbon in the study area are from the herbaceous angiosperm. V series of lignin acid (ADA) and wood. The ratio of Al ~ (2 +) to Al ~ (2 +) was 0.53 卤0.14 ~ (%), indicating that the degradation of organic matter from terrestrial sources was higher. The contribution of the three-terminal model of soil organic matter, terrestrial vascular plant-aquatic organic matter to land-based organic matter is analyzed by using the stable carbon isotope ratio 未 13 C and lignin content A 8. The results show that the soil organic matter, The average contributions of terrestrial vascular plants and aquatic organic matter were 59.9% 卤15.0 and 7.3% 卤7.0, respectively. The contribution of soil to land-based organic matter occupies an absolute advantage, which may be related to the low vegetation coverage and serious soil erosion in the Loess Plateau, the main source of sediments in the region.
【作者单位】：教育部地表过程与模拟重点实验室北京大学城市与环境学院;上海海洋大学海洋科学学院;上海深渊科学工程技术研究中心;
【基金】：国家自然科学基金项目(41476062)~~
【分类号】：P736.41

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