中国农业气象

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川西贡嘎山不同森林生态系统土壤有机碳垂直分布与组成特征

郭璐璐,李安迪,商宏莉,孙守琴   

  1. 1. 四川师范大学生命科学学院,成都 610000;2. 中国科学院水利部成都山地灾害与环境研究所山地表生过程和生态调控重点实验室,成都 610041
  • 出版日期:2018-10-20 发布日期:2018-10-16
  • 作者简介:郭璐璐 (1991-),女,硕士生,主要研究方向为生态学。E-mail:xyguolu@126.com]
  • 基金资助:
    国家自然科学基金项目(41473078)

Total and Labile Organic Carbon in Soils of Three Subalpine Forest Types in Gongga Mountain, Western Sichuan

GUO Lu-lu, LI An-di, SHANG Hong-li, SUN Shou-qin   

  1. 1. College of Life Science, Sichuan Normal University,Chengdu 610101,China; 2. Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041
  • Online:2018-10-20 Published:2018-10-16

摘要: 通过野外采样与室内实验相结合的方法,对川西典型亚高山不同海拔处暗针叶林、针阔混交林和常绿-落叶阔叶林3种森林类型表层土壤总有机碳(SOC)和活性有机碳的含量特征进行分析,旨在为亚高山生态系统土壤碳循环研究提供理论和数据支撑。结果表明:3种森林类型土壤中总有机碳含量(SOC)在44.21~179.98g·kg-1,表层(0-15cm)SOC含量大小顺序为针阔混交林>常绿-落叶阔叶林>暗针叶林,0-5cm土层SOC含量与活性有机碳含量均高于5-15cm土层,说明土壤有机碳具有土壤表聚现象。3种森林类型间SOC密度差异不显著,但不同森林类型土壤SOC密度沿土层的分布具有差别:与常绿-落叶阔叶林和暗针叶林相比,针阔混交林5-15cm土层SOC密度较高。土壤溶解性有机碳(DOC)、轻组分有机碳(LFOC)和微生物(MBC)含量均以针阔混交林最高,但其相对于SOC的比例则以暗针叶林最高,说明高海拔生态系统土壤活性有机碳有更大的累积,同时也暗示在气候变化背景下,高海拔生态系统可能具有更大的CO2排放风险。

关键词: 土壤有机碳, 活性有机碳, 森林类型, 亚高山

Abstract: In this study the concentration and distribution of soil organic carbon (SOC), as well as the labile SOC in soil of three forest types including an evergreen-deciduous broad-leaved forest, a mixed broadleaf-coniferous forest and a subalpine dark coniferous forest were investigated in western Sichuan, China. Results indicated that SOC concentration in the surface soil (0-15cm) across three forest types was 44.21-179.98g·kg-1, with the highest value in the mixed broadleaf?coniferous forest, followed by the evergreen-deciduous broad-leaved forest, and then the coniferous forest. In all of the three forests the soil of 0-5cm layer relative to that of 5?15cm layer had a higher SOC concentration, indicating a surface gathering characteristic of SOC in the forests. The SOC density did not differ among the three forests, while significant differences in light of the vertical variation of SOC density along soil depth were detected among the three forests, where the mixed broadleaf-conifer forest compared to the other two forests had a higher SOC density in the 5?15cm soil depth. Although the concentrations of dissolved organic carbon (DOC), light fraction organic carbon (LFOC) and microbial biomass carbon (MBC) were highest in the mixed broadleaf-conifer forest, the coniferous forest among the three forests was highest in the ratios of these parameters to total SOC content, indicating a higher accumulation of labile SOC in forest with a higher elevation. The results suggest that ecosystem with a higher elevation may have a higher risk of CO2 emission under the circumstance of the climate warming.

Key words: Organic carbon content, Carbon storage, Microbial biomass carbon, Labile organic carbon