植物生态学报 ›› 2018, Vol. 42 ›› Issue (1): 116-125.DOI: 10.17521/cjpe.2017.0297

• 研究论文 • 上一篇    下一篇

短期增温对紫花针茅草原土壤微生物群落的影响

王军1,2,王冠钦1,2,李飞1,2,彭云峰1,杨贵彪1,2,郁建春1,2,周国英3,杨元合1,2,*()   

  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, 北京 100049
    3 中国科学院西北高原生物研究所藏药研究重点实验室, 西宁 810008
  • 出版日期:2018-01-20 发布日期:2018-03-08
  • 通讯作者: 杨元合
  • 基金资助:
    国家自然科学基金(31670482)

Effects of short-term experimental warming on soil microbes in a typical alpine steppe

WANG Jun1,2,WANG Guan-Qin1,2,LI Fei1,2,PENG Yun-Feng1,YANG Gui-Biao1,2,YU Jian-Chun1,2,ZHOU Guo-Ying3,YANG Yuan-He1,2,*()   

  1. 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China

    2 University of Chinese Academy of Sciences, Beijing 100049, China

    3 Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China
  • Online:2018-01-20 Published:2018-03-08
  • Contact: Yuan-He YANG
  • Supported by:
    Supported by National Natural Science Foundation of China(31670482)

摘要:

土壤微生物是生态系统碳循环的重要参与者和调控者。全球变暖可能对土壤微生物群落产生影响, 加速陆地生态系统向大气中释放碳, 进而引起陆地碳循环对气候变暖的正反馈。然而, 目前学术界对土壤微生物群落如何响应气候变暖等问题认识不足, 尤其是缺乏低温干旱条件下土壤微生物对增温响应的实验证据。为此, 该文依托青藏高原紫花针茅(Stipa purpurea)草原建立的增温实验平台, 基于磷脂脂肪酸(PLFA)方法测定了2015和2016年生长季表层(0-10 cm)土壤微生物各类群的生物量, 在此基础上揭示气候变暖对紫花针茅草原土壤微生物群落结构的影响。结果显示, 短期增温处理导致2015和2016年生长季(5-10月)的表层土壤温度均显著提高1.6 ℃, 同时也导致土壤含水量显著下降了3.4%和2.4% (体积分数), 但并没有显著改变土壤化学性质及归一化植被指数。增温处理下, 两年生长季旺期(8月)的微生物生物量碳(MBC)含量分别为749.0和844.3 mg·kg -1, 微生物生物量氮(MBN)含量为43.1和102.1 mg·kg -1, 微生物生物量碳氮比分别为17.9和8.4, 但实验期间MBC、MBN和微生物生物量碳氮比与对照没有差异。PLFA分析的结果显示细菌在微生物群落中占主导, 而丛枝菌根真菌含量最少, 增温处理并没有改变不同类群的微生物生物量以及群落结构。进一步的分析显示, 土壤温度和含水量是调控土壤微生物群落变异的主要因子, 并且增温导致的微生物生物量碳的变化量分别与土壤温度和含水量的变化量呈显著正相关关系。以上结果表明, 由于受水分的限制, 短期增温对紫花针茅草原土壤微生物群落没有显著影响。

关键词: 气候变暖, 磷脂脂肪酸, 微生物群落, 青藏高原, 高寒草原

Abstract:

Aims Soil microbe plays key role in mediating terrestrial carbon cycles. It has been suggested that climate warming may affect the microbial community, which may accelerate carbon release and induce a positive feedback to soil climate warming. However, there is still controversy on how microbial community responds to experimental warming, especially in cold and drought environment.

Methods We conducted an open top chambers (OTCs) experiment to explore the effects of warming on soil microbial community in an alpine steppe on Qinghai-Xizang Plateau. During the maximum of the growing seasons (August) of 2015 and 2016, we monitored the biomass and structure of soil microbial community in warming and control plots using phospholipid fatty acids (PLFA) as biomarkers.

Important findings Short-term warming treatment significantly increased the soil temperature by 1.6 and 1.6 oC and decreased soil moisture by 3.4% and 2.4% (volume fraction) respectively, but did not alter either soil properties or normalized difference vegetation index (NDVI) during the growing season (from May to October) in 2015 and 2016. During the maximum of growing seasons (August) of 2015 and 2016, the magnitude of microbial biomass carbon (MBC) were 749.0 and 844.3 mg·kg-1, microbial biomass nitrogen (MBN) were 43.1 and 102.1 mg·kg-1, and the microbial biomass C:N ranged between 17.9 and 8.4. Moreover, all three showed no significant differences between warming and control treatments. The abundance of bacteria was the most in microbial community, while arbuscular mycorrhizal fungi was the least, and warming treatment did not alter the abundance of different microbial group and the microbial community structure. Nonetheless, our result revealed that warming-induced changes in MBC had significant positive correlation with changes in soil temperature and soil moisture. These patterns indicate that, microbial community in this alpine steppe may not respond substantially to future climate warming due to the limitation of soil drought. Therefore, estimation of microbial community response to climate change calls for consideration on the combined effect of warming and drought.

Key words: climate warming, phospholipid fatty acids (PLFA), microbial community, Qinghai-Xizang Plateau, alpine steppe