Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (8): 891-902.DOI: 10.17521/cjpe.2021.0085

Special Issue: 微生物生态学

• Research Articles • Previous Articles     Next Articles

Influences of warming and snow reduction in winter on soil nutrients and bacterial communities composition in a typical grassland of the Loess Plateau

MAO Jin1, DUO Ying1, DENG Jun2, CHENG Jie3, CHENG Ji-Min4, PENG Chang-Hui4,5, GUO Liang4,6,*()   

  1. 1College of Grassland Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, China
    2Administration Bureau of Ningxia Yunwushan National Nature Reserve, Guyuan, Ningxia 756000, China
    3Northwest Surveying Planning and Designing Institute of National Forestry and Grassland Administration, Xiʼan 710048, China
    4State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China
    5Institute of Environmental Sciences, University of Quebec at Montreal, Montreal H3C 3P8, Canada
    6Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling, Shaanxi 712100, China
  • Received:2021-03-12 Revised:2021-05-26 Online:2021-08-20 Published:2021-05-29
  • Contact: GUO Liang
  • Supported by:
    National Key R&D Program of China(2016YFC0500700);National Natural Science Foundation of China(41701606);Fundamental Research Funds for the Central Universities(2452020009)


Aims Variations in temperature and snow accumulations in winter will change the structure and function of the soil-microbial system. As a key biological factor in the terrestrial ecosystem, microorganisms play an important role in regulating soil nutrient cycles. However, they are very sensitive to environmental disturbances, especially to winter climate changes. It is in great need to study the response of soil nutrients and microbial properties of typical semi-arid grasslands to climate change in winter, in order to predict the ecological process and functional changes of grassland ecosystem in the long term.
Methods In the present study, the semi-arid grassland in the Yunwushan National Nature Reserve in Ningxia Province was taken as the research object. The four treatments including warming (W), snow reduction (S), interaction of warming and snow reduction (WS), and control (CK) were set to explore the responses of soil nutrients, enzyme activities and soil bacterial communities in the 0-5 cm soil layer of the typical grassland of the Loess Plateau to variations in winter temperature and snow cover.
Important findings Our results indicated that: (1) Warming, snow reduction and their interaction in winter increased the 0-5 cm soil temperature, lowered the relative humidity of the soil, but significantly increased the number of soil freeze-thaw cycles. (2) Compared with the control, other different treatments generally reduced the microbial biomass and bacterial diversity, which led to reduced activity of soil β-1,4-glucosidase (BG), β-1,4-N-acetylglucosaminidase (NAG) and alkaline phosphatase (AKP). The content of soil organic carbon, total nitrogen, available phosphorus, and nitrate nitrogen in the soil increased, while the content of nitrate nitrogen decreased. (3) The soil bacterial species in the study area were mainly Acidobacteria, Proteobacteria, Actinobacteria and Gemmatimonadetes. The dominant bacteria at the class level included Acidobacteria, γ-Proteobacteria, Thermophiles and σ-Proteobacteria. Redundancy analysis (RDA) results showed that available phosphorus (AP) content had the most significant impact on the bacterial community composition, with an explanation rate of 21.3% for the community variation. In conclusion, winter climate change can significantly affect soil temperature and humidity, especially the freezing and thawing cycles, which might further influence soil nutrients cycles, enzyme activities, and soil bacterial diversity. These results are of great significance for enriching and expanding the understanding of the process and mechanism of climate change on grassland ecosystem, as well as predicting the mid and long-term dynamic changes of typical grassland ecosystems.

Key words: soil nutrients, soil microorganisms, winter, warming, changes in snowfall