Bacterial phyla and clustering for the soil samples from the Tibetan plateau (TP). (A) Relative abundance of the identified bacterial phyla in the 20 soil samples. Detailed data of each phylum are listed in Additional file 1: Table S3. (B) Principal component analysis (PCA) of various soil samples based on the composition and abundance of their bacterial communities at the phylum level. Blue dots represent the TP samples in this study. Yellow dots represent previously reported soil samples from various environments.