Disparity in soil bacterial community succession along a short time-scale deglaciation chronosequence on the Tibetan Plateau

Global warming leads to deglaciations in high-elevation regions, which exposes deglaciated soils to microbial colonization. Disparity in year-to-year successional patterns of bacterial community and influencing factors in freshly deglaciated soils remain unclear.We explored the abundance of bacterial 16S rRNA gene and community succession in deglaciated soils along a 14-year chronosequence after deglaciation using qPCR and Illumina sequencing on the Tibetan Plateau. The results showed that the abundance of bacterial 16S rRNA gene gradually increased with increasing deglaciation age. Soil bacterial community succession was clustered into three deglaciation stages, which were the early (zero-year old), transitional (1–7 years old) and late (8–14 years old) stages. A significantly abrupt bacterial community succession occurred from the early to the transitional stage (P < 0.01), while a mild succession (P = 0.078) occurred from the transitional to the late stage. The bacterial community at the early and transitional stages were dominated by Proteobacteria, while the late stage was dominated by Actinobacteria. Less abundant ( < 10%) Acidobacteria, Gemmatimonadetes, Verrucomicrobia, Chloroflexi, Planctomycetes, unclassified bacteria dominantly occurred in the transition and late stage and Cyanobacteria in the early stage. Total organic carbon (24.7%), post deglaciation age (21%), pH (16.5%) and moisture (10.1%) significantly contributed (P < 0.05) to the variation of bacterial community succession. Our findings provided a new insight that short time-scale chronosequence is a good model to study yearly resolution of microbial community succession.