Characteristics of soil bacterial and fungal community of typical forest in the Greater Khingan Mountains based on high-throughput sequencing

Abstract:

[Background] The high latitude permafrost area in the Greater Khingan Mountains is the most sensitive region to climate change in China, and soil microorganisms play an essential role in maintaining the structure and function of forest ecosystem in the cold region. [Objective] In order to explore the soil microbial community structure of different forest types and its relationship with environmental factors in permafrost region of Greater Khingan Mountains. [Methods] Illumina Miseq high-throughput sequencing technology was applied to analyze the composition and diversity of soil bacterial and fungal communities in three typical forests (Larix gmelinii, Pinus sylvestris var. mongolica and Betula platyphlla). [Results] A total of 2 786 bacterial OTUs (Operational taxonomic units, OTUs) were obtained from three forest types, belonging to 38 phyla and 531 genera, of which the dominant phyla were Proteobacteria (31.45%?40.32%), Acidobacteria (14.24%?40.16%) and Actinobacteria (7.13%?22.15%); 1 803 fungal OTUs belong to 8 phyla and 263 genera with dominant phyla being Basidiomycota (40.43%?62.75%) and Ascomycota (35.81%?53.68%). Principal coordinate analysis showed that the differences between groups of bacterial and fungal communities were much greater than those within groups. Mantel test showed that the bacterial community structure was significantly correlated with pH, total nitrogen (TN), total phosphorus (TP) and soil water content (SWC) (P<0.05), and the correlation coefficient of pH was the largest. The fungal community structure was significantly correlated with SWC, TN and TP (P<0.05), and TN had the highest correlation coefficient. The results of redundancy analysis showed that the relative abundance of Proteobacteria and Basidiomycota was significantly positively correlated with TP. SWC and TN had a very significant positive correlation with the relative abundance of Acidobacteria and Ascomycota, and pH was positively relative to the Actinobacteria (P<0.05). [Conclusion] There are significant differences in soil microbial community structure among different forest types. Clarifying their distribution and main environmental driving factors are the key to grasp the process of forest ecosystem in cold regions.