热带海洋学报 ›› 2022, Vol. 41 ›› Issue (3): 16-28.doi: 10.11978/2021142

• 海洋地球化学 • 上一篇    下一篇

珠江口沉积物有机质特征、来源及其对碳存储的意义

商博文1,2,3, 吴云超1,2, 江志坚1,2,3, 刘松林1,2, 黄小平1,2,3()   

  1. 1.中国科学院热带海洋生物资源与生态重点实验室, 中国科学院南海海洋研究所, 广东 广州 510301
    2.南方海洋科学与工程广东省实验室(广州), 广东 广州 510348
    3.中国科学院大学, 北京 100049
  • 收稿日期:2021-10-25 修回日期:2021-12-16 发布日期:2021-12-20
  • 通讯作者: 黄小平
  • 作者简介:商博文(1996—), 湖南省宁乡市人, 男, 硕士研究生, 主要从事海洋环境生态学研究。
  • 基金资助:
    国家自然科学基金项目(41890852);国家自然科学基金项目(U1901221);南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项(GML2019ZD0405);广州市科技计划项目(202102021230)

Characteristics and sources of organic matter in sediments of the Pearl River Estuary: Carbon storage implications

SHANG Bowen1,2,3, WU Yunchao1,2, JIANG Zhijian1,2,3, LIU Songlin1,2, HUANG Xiaoping1,2,3()   

  1. 1. Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Guangzhou 510301, China
    2. Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2021-10-25 Revised:2021-12-16 Published:2021-12-20
  • Contact: HUANG Xiaoping
  • Supported by:
    National Natural Science Foundation of China(41890852);National Natural Science Foundation of China(U1901221);Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(GML2019ZD0405);Guangzhou Science and Technology Program(202102021230)

摘要:

河口沉积物作为承接陆海过程的重要载体, 是有机质赋存的主要形式之一。本文研究了珠江口沉积物总有机碳、总氮含量和沉积物可溶性有机物三维荧光特征, 以及其在口内区、混合区和口外区空间差异和影响因素, 并结合碳稳定同位素(δ13C)估算了珠江口各区域沉积物中不同来源有机质的贡献。结果显示: (1)沉积物总有机碳和总氮含量空间变化相似, 口内区和混合区域沉积有机质含量显著高于口外区; 主成分分析发现, 口内区沉积有机质含量主要受径流输入的影响, 口外区主要受Fe3+的影响; (2)MixSIAR稳定同位素混合模型结果显示, 口内区和混合区沉积有机质以陆源为主, 口外区则以海源为主; (3)珠江口沉积物新生有机质较多, 可快速被利用, 总体上不利于有机碳存储; 而陆源输入导致口内区和混合区沉积有机质腐殖化程度较高, 有机碳可存储性相对较高, 口外受海源有机质和铁氧化物—有机质复合体的影响, 有机碳可存储性相对较低。本研究可为深入认知河口区沉积有机质的生物地球化学过程及有机碳存储提供参考。

关键词: 沉积有机质, 陆源输入, 荧光特征, 有机碳存储, 珠江口

Abstract:

Estuarine sediment, as an important carrier of terrestrial and marine ecosystems, is one of the main forms of organic matter occurrence. In this study, we analyzed total organic carbon (TOC) concentration, total nitrogen (TN) concentration, soluble organic matter excitation emission matrix spectroscopy (EEMs), spatial differences and influencing factors in different areas. Carbon stable isotope (δ13C) was applied to estimate the contribution of sediment organic matter (SOM) in different regions of the Pearl River Estuary (PRE). The results are as follows. (1) Spatial variations of TOC and TN concentrations are similar. The concentrations of SOM in the inner estuary and mixed areas are significantly higher than those in the estuary mouth. Principal component analysis results show that SOM concentrations in the inner estuary and the mixed area are mainly affected by river flow input, and those in the estuary mouth, by ferric iron. (2) MixSIAR results show that SOM in the inner estuary and the mixed zone is still mainly from terrestrial sources, and that in the estuary mouth is primarily from marine sources. (3) Newly produced organic matter in the sediments, which can be quickly utilized, is highly enriched in the PRE. Terrestrial input induced the higher humification degree of SOM in the inner estuary and mixed areas, which is conducive to organic carbon storage processes. In contrast, low storage capability was implicated in the estuary mouth, due to the influence of marine sources and iron oxide-organic matter complex. This makes it unfavorable for the storage of organic carbon in the PRE. This study provides a supplementary reference for further understanding the biogeochemical process of SOM and carbon storage in estuaries.

Key words: Sediment organic matter, terrestrial input, fluorescence characteristics, organic carbon storage, Pearl River Estuary

中图分类号: 

  • P736.41