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应用生态学报 ›› 2020, Vol. 31 ›› Issue (6): 1844-1850.doi: 10.13287/j.1001-9332.202006.025

• 稳定同位素生态学专栏 • 上一篇    下一篇

基于稳定碳同位素的北京西山侧柏林生态系统呼吸区分

徐晓梧1, 李瀚之2, 余新晓1*, 贾国栋1   

  1. 1北京林业大学水土保持国家林业和草原局重点实验室, 北京 100083;
    2中国林业科学研究院荒漠化研究所, 北京 100091
  • 收稿日期:2019-12-27 出版日期:2020-06-15 发布日期:2020-06-15
  • 通讯作者: * E-mail: yuxinxiao111@126.com
  • 作者简介:徐晓梧, 女, 1991年生, 博士研究生。主要从事森林与大气间耦合研究。E-mail: xuxiaowu911121@163.com
  • 基金资助:
    国家自然科学基金项目(41877152,41430747)和林果业生态环境功能提升协同创新中心(CEFF-PXM2019-014207-000099)资助

Partitioning ecosystem respiration of a Platycladus orientalis forest in the west mountainous area of Beijing, China using stable carbon isotope

XU Xiao-wu1, LI Han-zhi2, YU Xin-xiao1*, JIA Gong-dong1   

  1. 1Key Laboratory of State Forestry and Grassland Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China;
    2Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China
  • Received:2019-12-27 Online:2020-06-15 Published:2020-06-15
  • Contact: * E-mail: yuxinxiao111@126.com
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (41877152, 41430747) and the Beijing Municipal Education Commission (CEFF-PXM2019-014207-000099).

摘要: 基于稳定碳同位素对北京西山侧柏林生态系统呼吸进行定量拆分,能够为该地区森林生态系统碳交换研究奠定基础。本研究采用光谱技术对森林不同高度处CO2浓度和δ13C值进行连续观测,同时采用土壤气室和枝条气室测定地下呼吸和地上呼吸的δ13C值,求得生态系统呼吸各组分比例。结合土壤呼吸通量的测定,实现对生态系呼吸的定量区分。结果表明: 森林生态系统各呼吸组分夜间δ13C值呈波动变化,植物地上呼吸δ13C值变化范围为-31.74‰~-23.33‰,土壤地下呼吸δ13C值变化范围为-32.11‰~-27.74‰,生态系统呼吸δ13C值介于二者之间。夜间平均土壤呼吸通量为1.70 μmol·m-2·s-1,占生态系统总呼吸的47%~91%;夜间地上呼吸量的平均值为0.72 μmol·m-2·s-1,对生态系统总呼吸的贡献较小。由同位素混合模型推算求得的日间呼吸变异大于温度响应模型的结果,其平均值分别为2.31和2.28 μmol·m-2·s-1

Abstract: Based on stable carbon isotope, we quantitatively partitioned ecosystem respiration in a Platycladus orientalis forest in the west mountainous area of Beijing. Results from this study could lay the foundation for carbon exchange research in forest ecosystems of this region. The spectroscopy technique was used to continuously measure CO2 concentrations and δ13C values at different height of the forest. Soil and branch chambers were used for measuring nighttime δ13C values in underground and aboveground respiration, and then the proportions of respiration components were calculated. Combined with soil respiration efflux measurement, ecosystem respiration was then quantitatively partitioned. The results showed that δ13C values of respiratory components fluctuated, which ranged from -31.74‰ to -23.33‰ in aboveground respiration of plants and from -32.11‰ to -27.74‰ in soil respiration. The δ13C values of ecosystem respiration was at the middle of those ranges. Soil respiration averaged 1.70 μmol·m-2·s-1 at night, accounting for 47%-91% of ecosystem respiration. Aboveground respiration averaged 0.72 μmol·m-2·s-1, contributing less to ecosystem respiration. Daytime respiration based on isotope mixing model calculation had greater variability than that based on temperature response model, with a mean value of 2.31 μmol·m-2·s-1 and 2.28 μmol·m-2·s-1, respectively.