2.5 Statistical analysis
Nonmetric multidimensional scale analysis (NMDS) was conducted based on the relative abundance of all groups at the phylum, class, family and genus levels of soil bacteria, and the significance of differences in soil bacterial communities among different types of vegetation was test by ANOSIM based on Bray‒Curtis distance. One-way ANOVA was used to analyse the significance of distance difference between any two of them, and the LSD method (least significant difference method) was used for posttest. The significance of differences in soil physicochemical properties, the α diversity indexes of the soil bacterial community and the relative abundances of the top ten phyla, classes, families and genera in the soil bacterial community among different vegetation types was analysed by one-way ANOVA, and the LSD method was used for the posttest. Based on the relative abundance data of major groups of phyla, class, family and genus in soil bacterial communities of different vegetation types, redundancy analysis (RDA) was used to explore the key soil factors affecting the composition differentiation of major groups at different classification levels of soil bacterial communities. The significance of soil factors was determined by the Monte Carlo test. Pearson correlation was used to analyse the correlation between soil factors and the α diversity index of soil bacterial communities and the relative abundance of major groups at the phylum, class, family and genus levels. Among them, NMDS, ANOSIM and RDA were all analysed using the programme package ”vegan” in R 4.2.2 software, and all other analyses and mapping were completed in R 4.2.2.