Chin J Plan Ecolo ›› 2018, Vol. 42 ›› Issue (1): 116-125.DOI: 10.17521/cjpe.2017.0297

Special Issue: 青藏高原植物生态学:植物-土壤-微生物

• Research Articles • Previous Articles     Next Articles

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)

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