植物生态学报 ›› 2011, Vol. 35 ›› Issue (9): 946-954.DOI: 10.3724/SP.J.1258.2011.00946

• 研究论文 • 上一篇    下一篇

中国南亚热带森林不同演替阶段土壤呼吸的分离量化

韩天丰1, 周国逸2,1,*(), 李跃林2, 刘菊秀2, 张德强2   

  1. 1华南农业大学林学院, 广州 510642
    2中国科学院华南植物园, 广州 510650
  • 收稿日期:2011-04-18 接受日期:2011-06-21 出版日期:2011-04-18 发布日期:2011-09-01
  • 通讯作者: 周国逸
  • 作者简介:*(E-mail:gyzhou@scib.ac.cn)

Partitioning soil respiration in lower subtropical forests at different successional stages in southern China

HAN Tian-Feng1, ZHOU Guo-Yi2,1,*(), LI Yue-Lin2, LIU Ju-Xiu2, ZHANG De-Qiang2   

  1. 1College of Forestry, South China Agricultural University, Guangzhou 510642, China
    2South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
  • Received:2011-04-18 Accepted:2011-06-21 Online:2011-04-18 Published:2011-09-01
  • Contact: ZHOU Guo-Yi

摘要:

量化森林土壤呼吸(RS)及其组分对准确地评估森林土壤碳吸存极其重要。该文以鼎湖山南亚热带季风常绿阔叶林及其演替系列针阔叶混交林和马尾松(Pinus massoniana)林为研究对象, 采用挖壕沟法结合静态气室CO2测定法对这3种林分类型的RS进行分离量化。结果表明: 鼎湖山3种森林演替系列上的森林RS及其组分(自养呼吸RA、异养呼吸RH)均呈现出明显的季节动态, 表现为夏季最高、冬季最低的格局。在呼吸总量上, 季风常绿阔叶林显著高于针阔叶混交林和马尾松林, 但混交林与马尾松林之间差异不显著; RA除季风常绿阔叶林显著大于针阔叶混交林外, 其余林分之间差异不显著; 对于RH来说, 3个林分之间均无显著差异。随着森林正向演替的进行, 由马尾松林至针阔叶混交林至季风常绿阔叶林, RA对土壤总呼吸的年平均贡献率分别为(39.48 ± 15.49)%、(33.29 ± 17.19)%和(44.52 ± 10.67)%, 3个林分之间差异不显著。方差分析结果表明, 土壤温度是影响RS及其组分的主要环境因子, 温度与RS及其组分呈显著的指数关系; 土壤含水量对RS的影响不显著, 甚至表现为轻微的抑制现象, 但未达到显著性水平。对温度敏感性指标Q10值的分析表明, 3个林分均为RA的温度敏感性最大, RH的温度敏感性最小。

关键词: 自养呼吸, 森林演替, 异养呼吸, 南亚热带森林, Q10

Abstract:

Aims Quantifying forest soil respiration (RS) components is vital to accurately evaluate carbon sequestration of forest ecosystems. Our objectives were to determine (1) seasonal variations in RS and its components of autotrophic (RA) and heterotropic respiration (RH) in subtropical forests, (2) the relative contributions of RA and RH to RS in the three subtropical forests and (3) relationships between RS and temperature and water content.
Methods We used the trenching-plot and infrared gas exchange analyzer approaches to determine RA and RH in the soil surface CO2 flux for monsoon evergreen broad-leaved forest (MEBF) and its early succession communities, coniferous and broad-leaved mixed forest (MF) and coniferous masson pine forest (MPF) in southern China. Rate of RS was measured twice a month in the hot, humid season (April-September) and once a month in the cool, dry season (October-March). Soil temperature and soil water content were measured at the same time.
Important findings RS, RA and RH varied markedly during the year with high rates in the hot, humid season and low rates in the cool, dry season. RS rate measured in the trenched plots (RH) at these forests showed an increasing trend with succession, but the change was not statistically significant. RS and RA followed a similar seasonal trend and were highest in MEBF and lowest in MF. Contribution of RA to RS was (39.48±15.49)%, (33.29±17.19)% and (44.52±10.67)% in MPF, MF and MEBF, respectively. Repeated measurement ANOVA indicated that soil temperature was the main factor that affected RS and its components, and there was a significant exponential relationship between them. While there was no significant relationship between soil water content and soil respiration flux, there appears to be a mild inhibition phenomenon. Soil Q10 values increased with succession, whereas autotrophic respiration (RA) is more sensitive to temperature in all stands.

Key words: autotrophic respiration, forest succession, heterotrophic respiration, lower subtropical forest, Q10