地学前缘 ›› 2011, Vol. 18 ›› Issue (6): 150-160.

• 论文 • 上一篇    下一篇

乌裕尔河流域颗粒有机碳的来源:碳同位素证据

侯青叶, 杨忠芳, 余涛, 顾兆炎, 夏学齐, 沈承德   

  1. 1. 中国地质大学(北京) 地球科学与资源学院, 北京 100083
    2. 中国科学院 地质与地球物理研究所, 北京 100029
    3. 中国科学院 广州地球化学研究所, 广东 广州 510640
  • 收稿日期:2011-10-30 修回日期:2011-11-10 出版日期:2011-11-25 发布日期:2011-12-05
  • 作者简介:侯青叶(1978—),女,副教授,地球化学专业,主要从事环境地球化学研究。E-mail: qingyehou@cugb.edu.cn
  • 基金资助:

    国土资源部公益性行业科研项目(200911020);中国地质调查局地质大调查项目(1212010511218,1212011087125)

Origin of particulate organic carbon in the Wuyuer River: Carbon isotopic evidences.

  1. 1. School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
    2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
    3. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
  • Received:2011-10-30 Revised:2011-11-10 Online:2011-11-25 Published:2011-12-05

摘要:

以2008、2009年所采集的乌裕尔河9个点位水体中的悬浮物为研究对象,对丰、枯水期颗粒有机碳(POC)含量、碳同位素组成(13C、14C)及表观年龄进行了系统测试与分析,以期探讨河流中颗粒有机碳来源与流域土壤侵蚀的关系。研究结果表明,该河流中颗粒有机碳(POC)主要来源于未受玉米残体及根系输入影响的深层土壤,且土壤中的有机质主要为原始荒草植被残体;扎龙湿地颗粒有机碳则以自生的现代碳为主。支、干流丰水期颗粒有机碳的14C表观年龄远远老于枯水期的表观年龄,丰水期颗粒有机质的迁移距离较短,枯水期则刚好相反。与其他河流颗粒有机碳14C表观年龄对比结果表明,研究区土壤侵蚀非常严重,且存在显著的季节性差异。综合考虑颗粒有机碳迁移距离及其来源的差异,根据端员混合模型计算了丰水期各支流对不同干流采样点颗粒有机碳的贡献率。

关键词: 颗粒有机碳;碳同位素;土壤侵蚀;乌裕尔河, 流域

Abstract:

Suspended solids were sampled at 9 sites on the Wuyuer River and its main tributaries in 20082009. Contents, stable carbon isotopes (13C) and cosmogenic carbon isotope (14C) compositions of particulate organic carbon (POC) in suspended solids were used to constrain the relationship between the sources of particulate organic carbon and soil erosion in drainage basin. Particulate organic carbon is mainly of organic matter of deep soil. Also, the organic matter in deep soil is dominated by grassland vegetation residue, and lack of corn root residue. Particulate organic carbon of suspended solids in Zhalong wetlands is mainly determined by modern carbon formed in it, with little or absence of terrestrial influence. 14C apparent ages of  POC  of Wuyuer River and its main tributaries in high water periods are older than those in low water periods. The migration distance of particulate matter in rainfall season is shorter than that in rainless season. Compared to the other rivers, the characteristic and variability of 14C apparent ages of particulate organic carbon suggested that soil erosion in Wuyuer River is very severe, and show obvious seasonal difference. Considering the difference of origin and migration distance of particulate organic carbon, we calculated the contribution of main tributaries to Wuyuer River in high water periods from the mixing model.

Key words: particulate organic carbon (POC), carbon isotope, soil erosion; , Wuyuer River, drainage basin

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