植物生态学报 ›› 2017, Vol. 41 ›› Issue (12): 1239-1250.doi: 10.17521/cjpe.2017.0208

• 研究论文 • 上一篇    下一篇

降水格局改变背景下土壤呼吸变化的主要影响因素及其调控过程

杨青霄1,2, 田大栓2, 曾辉1,4,*(), 牛书丽2,3   

  1. 1北京大学深圳研究生院城市规划与设计学院, 深圳 518055
    2中国科学院地理科学与资源研究所生态网络观测与模拟重点实验室, 北京 100101

    3中国科学院大学资源与环境学院, 北京 100049
    4北京大学城市与环境学院, 北京大学地表过程分析与模拟教育部重点实验室, 北京 100871
  • 出版日期:2017-12-10 发布日期:2018-02-23
  • 通讯作者: 曾辉 E-mail:zengh@pkusz.edu.cn
  • 基金资助:
    国家自然科学基金(31470528和31625006)

Main factors driving changes in soil respiration under altering precipitation regimes and the controlling processes

YANG Qing-Xiao1,2, TIAN Da-Shuan2, ZENG Hui1,4,*(), NIU Shu-Li2,3   

  1. 1School of Urban Planning and Design, Peking University Shenzhen Graduate School, Shenzhen 518055, China

    2Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China

    3College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
    and
    4Key Laboratory for Earth Surface Processes of the Ministry of Education, Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
  • Online:2017-12-10 Published:2018-02-23
  • Contact: ZENG Hui E-mail:zengh@pkusz.edu.cn

摘要:

全球气候变化带来降水格局的改变。土壤呼吸是土壤碳库向大气释放CO2的重要途径, 其对降水变化的响应对陆地生态系统碳循环和全球气候变化进程有着重要的意义。该研究收集了来自全球各地土壤呼吸对降水变化响应的控制试验结果进行分析, 以揭示降水格局变化对土壤呼吸影响的普遍规律和控制机制。结果显示: 增加降水促进土壤呼吸2%-135%, 减少降水抑制土壤呼吸19%-24%, 当降水改变量标准化到所有处理的平均值(当年当地降水量的41%)时, 增加降水促进的土壤呼吸量(49%)显著大于减少降雨抑制的土壤呼吸量(21%)。土壤湿度是降水变化下驱动土壤呼吸改变的主要因子, 其一方面直接影响土壤呼吸, 另一方面通过影响土壤微生物碳库、地上/地下净初级生产力来影响土壤呼吸, 总解释度高达98%。同时土壤呼吸对降水变化的响应程度随着环境温度和降水量发生变化。土壤呼吸对降水增加的敏感性随环境温度的升高没有显著变化, 但对降水减少的敏感性随着环境温度的升高逐渐增强。随着环境降水量的逐渐增加, 土壤呼吸对降水增加和减少的敏感性均呈现下降趋势。说明在未来全球降水格局的改变下, 土壤呼吸对降水变化的响应有很大的区域差异, 受当地气候条件的影响。

关键词: 土壤呼吸, 碳循环, 整合分析, 降水变化

Abstract:
Aims Our objective was to determine the effects of changes in global pattern of precipitation on soil respiration and the controlling factors. Methods Data were collected from literature on precipitation manipulation experiments globally and a meta-analysis was conducted to synthesize the responses of soil respiration to changes in precipitation regimes. Important findings We found that an increased precipitation stimulated soil respiration while a decreased precipitation suppressed it. When changes in rainfall were normalized to the average treatment level (41% of the current annual precipitation), the level of increases in soil respiration with increased precipitation (49%) were higher than that of decreases with decreased precipitation (21%), showing an asymmetric responses of soil respiration to increases and decreases in precipitation. Soil moisture occurred as the most predominant factor driving the changes in soil respiration under altered precipitation. Changes in soil moisture affected soil respiration directly and indiscreetly by changing aboveground/belowground net primary productivity and microbial biomass carbon, which collectively contributed 98% of variations in soil respiration. In addition, the responses of soil respiration to altered precipitation varied with background temperature and precipitation. The sensitivity of soil respiration increased with local mean annual temperature when precipitation was reduced, while remaining unchanged when precipitation was increased. Meanwhile, the sensitivity of soil respiration to either increases or decreases in precipitation decreased with increasing local mean annual precipitation. Under future altered precipitation regimes, the sensitivity of soil respiration to changes in precipitation is likely dependent of local environment conditions.

Key words: soil respiration, carbon cycle, meta-analysis, precipitation change