植物生态学报 ›› 2019, Vol. 43 ›› Issue (2): 152-164.doi: 10.17521/cjpe.2017.0280

• 研究论文 • 上一篇    下一篇

底座入土深度和面积对典型草原土壤呼吸测定结果的影响

李建军1,2,刘恋1,2,陈迪马1,许丰伟1,2,程军回3,白永飞1,**()   

  1. 1 中国科学院植物研究所植被与环境变化国家重点实验室, 北京 100093
    2 中国科学院大学资源与环境学院, 北京 100049
    3 新疆农业大学草业与环境科学学院, 乌鲁木齐 830052
  • 收稿日期:2017-11-02 接受日期:2018-04-19 出版日期:2019-02-20 发布日期:2019-06-04
  • 通讯作者: 白永飞 E-mail:yfbai@ibcas.ac.cn
  • 基金资助:
    国家自然科学基金(31320103916);国家自然科学基金(31630010)

Effects of collar size and buried depth on the measurement of soil respiration in a typical steppe

LI Jian-Jun1,2,LIU Lian1,2,CHEN Di-Ma1,XU Feng-Wei1,2,CHENG Jun-Hui3,BAI Yong-Fei1,**()   

  1. 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2 College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
    3 College of Grassland and Environment Science, Xingjiang Agricultural University, ürümqi 830052, China;
  • Received:2017-11-02 Accepted:2018-04-19 Online:2019-02-20 Published:2019-06-04
  • Contact: BAI Yong-Fei E-mail:yfbai@ibcas.ac.cn
  • Supported by:
    Supported by the National Natural Science Foundation of China(31320103916);Supported by the National Natural Science Foundation of China(31630010)

摘要:

生态学家对土壤呼吸开展了大量研究, 但很少评估“底座”对土壤呼吸测量结果的影响, 特别是底座入土深度和面积对土壤呼吸测定结果的影响。为此, 该研究在内蒙古典型草原设置了2个底座面积(15 cm × 15 cm和30 cm × 30 cm)和2个底座入土深度(2 cm和5 cm)处理, 采用气室法在植物生长季对土壤呼吸进行了测定, 分析评估了底座面积和入土深度对土壤呼吸测定结果的影响。结果显示: 与底座入土较浅和面积较小的处理相比, 底座入土较深和面积较大的处理, 土壤呼吸测定值分别降低了8.0%-9.7%和9.1%-10.8%; 这两个处理的底座内土壤温度显著升高, 土壤含水量显著下降, 地上净初级生产力显著降低。结构方程模型分析表明, 底座入土较深、面积较大的处理, 主要通过降低地上净初级生产力和土壤含水量, 增加土壤温度, 使土壤呼吸下降, 各因子共同解释了土壤呼吸变异的89%。研究发现, 在使用气室法测定土壤呼吸时, 底座入土深度和面积对土壤呼吸测定结果具有显著影响, 评估底座处理效应对准确测定土壤呼吸强度具有重要的意义。理论上, 适当降低底座入土深度和底座面积大小, 将有助于准确测定土壤呼吸。但在实践中, 由于土壤异质性的影响, 减少底座面积可能会增加新的测量误差, 只能考虑适当降低底座入土深度。

关键词: 底座, 净初级生产力, 土壤温度, 土壤含水量, 克隆整合, 季节动态, CO2, 结构方程模型

Abstract:
Aims Soil respiration plays an important role in carbon cycling in grassland ecosystems. However, the effects of collar size and buried depth during field measurement on soil respiration are rarely assessed.
Methods We conducted a two-factor experiment to examine how soil collar depth (2 cm and 5 cm) and size (15 cm × 15 cm and 30 cm × 30 cm) affected the soil respiration (SR), post aboveground net primary productivity (post-ANPP), soil temperature (ST), and soil water content (SWC) in a semi-arid steppe.
Important findings The results showed that the deep-inserted soil collar (5 cm soil depth) decreased the soil respiration by 8.0%-9.7% compared with the shallow-inserted soil collar (2 cm soil depth). The large-sized soil collar (30 cm × 30 cm) decreased the soil respiration by 9.1%-10.8% compared with the small-sized soil collar (15 cm × 15 cm). We also found that the deep-inserted and large-sized soil collars had higher ST but lower SWC compared with the shallow-depth and small-sized soil collars. Structural equation model indicated that the lower respiration in the deep-inserted and large-sized soil collars was due to the lower post-ANPP, ST, and SWC. Overall, we found that the soil collar size and buried depth can substantially alter the magnitude of soil respiration by changing plant biomass, ST, and SWC. These findings suggest that the influences of collar size and buried depth on soil respiration should be considered for better estimation and modeling of soil CO2 fluxes in terrestrial ecosystems.

Key words: collar, net primary productivity, soil temperature, soil water content, clonal integration, seasonal dynamics, CO2, structural equation model