中国地理科学 ›› 2019, Vol. 20 ›› Issue (4): 700-711.doi: 10.1007/s11769-019-1062-y

• 论文 • 上一篇    下一篇

Molecular Fingerprints of Soil Organic Matter in a Typical Freshwater Wetland in Northeast China

LI Zhe1,2, ZHANG Zhongsheng2, XUE Zhenshan2, SONG Xiaolin2, ZHANG Hongri1, WU Haitao2, JIANG Ming2, LYU Xianguo2   

  1. 1. College of Geomatics, Shandong University of Science and Technology, Qingdao 266590, China;
    2. Northeast Institute of Geography and Agroecology, Chinese Academy of Science, Changchun 130024, China
  • 收稿日期:2018-12-16 修回日期:2018-09-06 出版日期:2019-08-27 发布日期:2019-06-28
  • 通讯作者: ZHANG Zhongsheng.Email:zzslycn@iga.ac.cn E-mail:zzslycn@iga.ac.cn
  • 基金资助:

    Under the auspices of the National Key R&D Program of China (No. 2016YFC0500404), the National Natural Science Foundation of China (No. 41671087, 41671081, 41771103), and the Youth Innovation Promotion Association, Chinese Academy of Sciences (No. 2018265).

Molecular Fingerprints of Soil Organic Matter in a Typical Freshwater Wetland in Northeast China

LI Zhe1,2, ZHANG Zhongsheng2, XUE Zhenshan2, SONG Xiaolin2, ZHANG Hongri1, WU Haitao2, JIANG Ming2, LYU Xianguo2   

  1. 1. College of Geomatics, Shandong University of Science and Technology, Qingdao 266590, China;
    2. Northeast Institute of Geography and Agroecology, Chinese Academy of Science, Changchun 130024, China
  • Received:2018-12-16 Revised:2018-09-06 Online:2019-08-27 Published:2019-06-28
  • Contact: ZHANG Zhongsheng.Email:zzslycn@iga.ac.cn E-mail:zzslycn@iga.ac.cn
  • Supported by:

    Under the auspices of the National Key R&D Program of China (No. 2016YFC0500404), the National Natural Science Foundation of China (No. 41671087, 41671081, 41771103), and the Youth Innovation Promotion Association, Chinese Academy of Sciences (No. 2018265).

摘要:

Natural wetlands are known to store huge amounts of organic carbon in their soils. Despite the importance of this storage, uncertainties remain about the molecular characteristics of soil organic matter (SOM), a key factor governing the stability of soil organic carbon (SOC). In this study, the molecular fingerprints of SOM in a typical freshwater wetland in Northeast China were investigated using pyrolysis gas-chromatography/mass-spectrometry technology (Py-GC/MS). Results indicated that the SOC, total nitrogen (TN), and total sulfur contents of the cores varied between 16.88% and 45.83%, 0.93% and 2.82%, and 1.09% and 3.79%, respectively. The bulk δ13C and δ15N varied over a range of 9.85‰, between -26.85‰ and -17.00‰, and between -0.126‰ and 1.002‰, respectively. A total of 134 different pyrolytic products were identified, and they were grouped into alkyl (including n-alkanes (C:0) and n-alkenes (C:1), aliphatics (Al), aromatics (Ar), lignin (Lg), nitrogen-containing compounds (Nc), polycyclic aromatic hydrocarbons (PAHs), phenols (Phs), polysaccharides (Ps), and sulfur-containing compounds (Sc). On average, Phs moieties accounted for roughly 24.11% peak areas of the total pyrolysis products, followed by Lg (19.27%), alkyl (18.96%), other aliphatics (12.39%), Nc compounds (8.08%), Ps (6.49%), aromatics (6.32%), Sc (3.26%), and PAHs (1.12%). Soil organic matter from wetlands had more Phs and Lg and less Nc moieties in pyrolytic products than soil organic matters from forests, lake sediments, pastures, and farmland. δ13C distribution patterns implied more C3 plant-derived soil organic matter, but the vegetation was in succession to C4 plant from C3 plant. Significant negative correlations between Lg or Ps proportions and C3 plant proportions were observed. Multiple linear analyses implied that the Ar and Al components had negative effects on SOC. Alkyl and Ar could facilitate ratios between SOC and total nitrogen (C/N), while Al plays the opposite role. Al was positively related to the ratio of dissolved organic carbon (DOC) to SOC. In summary, SOM of wetlands might characterize by more Phs and lignin and less Nc moieties in pyrolytic products. The use of Pyrolysis gas-chromatography/mass-spectrometry (Py-GC/MS) technology provided detailed information on the molecular characteristics of SOM from a typical freshwater wetland.

关键词: molecular fingerprint, soil organic matter, pyrolysis gas-chromatography/mass-spectrometry, freshwater marsh, Northeast China

Abstract:

Natural wetlands are known to store huge amounts of organic carbon in their soils. Despite the importance of this storage, uncertainties remain about the molecular characteristics of soil organic matter (SOM), a key factor governing the stability of soil organic carbon (SOC). In this study, the molecular fingerprints of SOM in a typical freshwater wetland in Northeast China were investigated using pyrolysis gas-chromatography/mass-spectrometry technology (Py-GC/MS). Results indicated that the SOC, total nitrogen (TN), and total sulfur contents of the cores varied between 16.88% and 45.83%, 0.93% and 2.82%, and 1.09% and 3.79%, respectively. The bulk δ13C and δ15N varied over a range of 9.85‰, between -26.85‰ and -17.00‰, and between -0.126‰ and 1.002‰, respectively. A total of 134 different pyrolytic products were identified, and they were grouped into alkyl (including n-alkanes (C:0) and n-alkenes (C:1), aliphatics (Al), aromatics (Ar), lignin (Lg), nitrogen-containing compounds (Nc), polycyclic aromatic hydrocarbons (PAHs), phenols (Phs), polysaccharides (Ps), and sulfur-containing compounds (Sc). On average, Phs moieties accounted for roughly 24.11% peak areas of the total pyrolysis products, followed by Lg (19.27%), alkyl (18.96%), other aliphatics (12.39%), Nc compounds (8.08%), Ps (6.49%), aromatics (6.32%), Sc (3.26%), and PAHs (1.12%). Soil organic matter from wetlands had more Phs and Lg and less Nc moieties in pyrolytic products than soil organic matters from forests, lake sediments, pastures, and farmland. δ13C distribution patterns implied more C3 plant-derived soil organic matter, but the vegetation was in succession to C4 plant from C3 plant. Significant negative correlations between Lg or Ps proportions and C3 plant proportions were observed. Multiple linear analyses implied that the Ar and Al components had negative effects on SOC. Alkyl and Ar could facilitate ratios between SOC and total nitrogen (C/N), while Al plays the opposite role. Al was positively related to the ratio of dissolved organic carbon (DOC) to SOC. In summary, SOM of wetlands might characterize by more Phs and lignin and less Nc moieties in pyrolytic products. The use of Pyrolysis gas-chromatography/mass-spectrometry (Py-GC/MS) technology provided detailed information on the molecular characteristics of SOM from a typical freshwater wetland.

Key words: molecular fingerprint, soil organic matter, pyrolysis gas-chromatography/mass-spectrometry, freshwater marsh, Northeast China