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.