Establishing a terrestrial proxy based on fluorescent dissolved organic matter from sediment pore waters in the East China Sea
Establishing a terrestrial proxy based on fluorescent dissolved organic matter from sediment pore waters in the East China Sea
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建立基于东海沉积物孔隙水中荧光溶解有机物的陆地代理
DOI：
10.1016/j.watres.2020.116005
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发表时间：
2020
期刊：
影响因子：
12.8
通讯作者：
Zhang Chuanlun
中科院分区：
文献类型：
--
作者：
Li Minchun;Xie Wei;Li Penghui;Yin Kedong;Zhang Chuanlun
陆地有机质在海洋有机碳库中占有重要地位。一些陆地代用指标，如分支和异戊二烯四醚（BIT）指数，已成功地用于指示海洋沉积物中的陆地有机质的相对丰度。建立了一种新的基于沉积物孔隙水荧光溶解有机物（FDOM）的陆地代用指标。对东海沿岸42个站位的表层沉积物样品进行了FDOM的分布特征研究。利用荧光激发-发射矩阵平行因子分析（EEMS-PARAFAC）方法，对FDOM的3个类蛋白质组分（C1、C4和C5）和2个类腐殖酸组分（C2和C3）进行了鉴定。在空间上，这5种组分的强度从海岸向海洋逐渐增强，其中蛋白质类组分的变化趋势更为明显，说明这5种组分都有一定的本地贡献。然而，C2和C3的比例，特别是C2，主要对应于峰A的荧光激发-发射矩阵的比例，显着降低，从海岸到海洋，并显着相关的BIT指数从相应的固体馏分。研究表明，沉积物中陆源有机质类腐殖酸组分部分释放到孔隙沃茨中的C2和C3库中，这可能受到特定环境条件的制约。因此，可以将孔隙沃茨中的FDOM与BIT指数结合起来，验证FDOM的性质，并将其作为生物标志物来反映近岸海洋不同生态地球化学过程介导的有机质陆源输入。C2的荧光峰A的比例被认为是FDOM衍生的一个新的陆地。(C)2020年，任作家。爱思唯尔有限公司出版
Terrestrial organic matter occupies an important position in the oceanic organic carbon pool. Some terrestrial proxies, like the Branched and Isoprenoid Tetraether (BIT) index, have been applied successfully to indicate the relative abundance of terrestrial organic matter in marine sediments. A new terrestrial proxy derived from sediment pore water fluorescent dissolved matter (fluorescent dissolved organic matter (FDOM)) was developed in this study. Surface sediment samples were collected from forty-two sites in the coastal region of the East China Sea (ECS) to examine the distributional patterns of FDOM. Three protein-like components (C1, C4 and C5) and two humic-like components (C2 and C3) of FDOM were identified using fluorescence excitation-emission matrices parallel factor analysis (EEMs-PARAFAC). Spatially, the intensity of these five components generally increased from the coast to the ocean with protein-like components showing a more obvious trend, which suggested that all five components had autochthonous contribution. However, the C2 and C3 proportions, especially C2 that mainly corresponds to the proportion of peak A in fluorescence excitation-emission matrices, significantly decreased from the coast to the ocean and significantly correlated with the BIT index from corresponding solid fractions. We posit that part of the humic-like components from terrestrial organic matter in sediments are released into the C2 and C3 pools in pore waters, which may be constrained by specific environmental conditions. Thus, the FDOM from pore waters can be integrated with BIT index to validate the nature of FDOM and use it as a biomarker to reflect the terrestrial input of organic matter mediated by different biogeochemical processes in coastal oceans. The proportion of peak A responsible for the fluorescence of C2 was suggest as a new terrestrial derived from FDOM. (C) 2020 The Authors. Published by Elsevier Ltd.