[Soil bacterial community structure and predicted functions in the larch forest during succession at the Greater Khingan Mountains of Northeast China].

To reveal soil bacterial community structure and potential functions in larch forest during succession at Greater Khingan Mountains (Hanma National Nature Reserve), 16S rDNA was sequencing by Illumina Miseq. The results showed that the Proteobacteria, Acidobacteria, Verrucomicrobia, Bacteroidetes, Actinobacteria, Planctomycetes and Chloroflexi were the most dominant phyla in soils of larch forests at various successional stages. Along forest succession, Acidobacteria increased, while Chloroflexi decreased. Relative abundance of dominant phyla was different at various successional stages. The α diversity, Chao1, Shannon index and Simpson index of soil bacterial community had no significant difference among five succession stages, while significant differences in soil bacterial community structure were observed between young and medium larch, between young and over mature larch, and between near mature and mature larch. Bacterial community structure was mainly influenced by redox potential, pH and available phosphorus. The redox potential was the most important factor influencing soil bacterial community structure. Along the succession of larch forest, N-fixation, denitrification, ammonia oxidation and lignin breakdown decreased, dissimilatory sulfate reduction had down-up trend, carbon fixation had up-down trend, and alkaline phosphatase had no apparent trend. Bacterial community potential function was mainly influenced by redox potential and available phosphorus.