文献类型： 外文期刊

作者： Jiang, Tao ¹ ; Kaal, Joeri ³ ; Liang, Jian ¹ ; Zhang, Yaoling; Wei, Shiqiang ¹ ; Wang, Dingyong ¹ ; Green, Nelson W ¹ ;

作者机构： 1.Southwest Univ, Key Lab Ecoenvironm Three Gorges Reservoir Reg, Chongqing Key Lab Agr Resources & Environm, Coll Resources & Environm,Minist Educ, Chongqing 400716, Peoples R China

2.Swedish Univ Agr Sci, Dept Forest Ecol & Management, SE-90183 Umea, Sweden

3.Univ Santiago de Compostela, Dept Edafol & Quim Agr, Ciencia Sistema Terra, Campus Sur S-N, Santiago De Compostela 15782, Spain

4.CSIC, Inst Ciencias Patrimonio Incipit, Avda Vigo SN, Santiago De Compostela 15705, Spain

关键词： Soil;Dissolved organic matter;Water-soluble organic matter;Three Gorges Reservoir;Characterization;Natural organic matter

期刊名称：SCIENCE OF THE TOTAL ENVIRONMENT （ 影响因子：8.2； 五年影响因子：8.6 ）

ISSN： 0048-9697

年卷期： 2017 年 603 卷

页码：

收录情况： SCI

摘要： Soil-derived dissolved organic matter (DOM) has a major influence in biogeochemical processes related to contaminant dynamics and greenhouse gas emissions, due to its reactivity and its bridging role between the soil and aquatic systems. Within the Three Gorges Reservoir (TGR, China) area, an extensive water-fluctuation zone periodically submerges the surrounding soils. Here we report a characterization study of soil-derived DOM across the TGR areas, using elemental and optical analysis, infrared spectroscopy (FTIR), pyrolysis-GC-MS (Py-GC-MS) and thermally assisted hydrolysis and methylation (THM-GC-MS). The results showed that the soil DOM from the TGR area is a mixture of "allochthonous" (i.e., plant-derived/terrigenous) and "autochthonous" (i.e., microbial) origins. The terrigenous DOM is composed primarily of phenolic and aliphatic structures from lignin and aliphatic biopolymers (i.e. cutin, suberin), respectively. Multivariate statistics differentiated between two fractions of the microbial DOM, i.e. chitin-derived, perhaps from fungi and arthropods in soil, and protein-derived, partially sourced from algal or aquatic organisms. Molecular proxies of source and degradation state were in good agreement with optical parameters such as SUVA(254), the fluorescence index (FI) and the humification index (HIX). The combined use of elemental analysis, fluorescence spectroscopy, and Py-GC-MS provides rigorous and detailed DOM characterization, whereas THM-GC-MS is useful for more precise but qualitative identification of the different phenolic (cinnamyl, p-hydroxyphenyl, guaiacyl, syringyl and tannin-derived) and aliphatic materials. With the multi-methodological approach used in this study, FTIR was the least informative, in part, because of the interference of inorganic matter in the soil DOM samples. The soil DOM from the TGR's water fluctuation zone exhibited considerable compositional diversity, mainly related to the balance between DOM source (microbial- or plant-derived), local vegetation and anthropogenic activities (e.g., agriculture). Finally, the relationship between DOM composition and its potential reactivity with substances of environmental concerns in the TGR area are also discussed. (C) 2017 Elsevier B.V. All rights reserved.