3.7 Relationship between soil bacterial community composition and soil physicochemical properties
RDA revealed that soil pH, AP, NH4+-N, SWW and SBD were significant factors driving the composition of major groups of soil bacterial communities at the phylum, class, family and genus levels (P <0.05) (Fig. 6, Table 2). The relative abundances of Bacteroidetes and Elusimicrobia were significantly positively correlated with soil pH, while the relative abundances of Actinobacteria, Planctomycotes, Chlamydiae, and Firmicutes were significantly negatively correlated with soil pH (Fig. 6A, Table S1). The relative abundances of Actinobacteria, unclassified_k__norank, Planctomycetes and Chlamydiae were significantly positively correlated with AP. The relative abundance of Proteobacteria, Bacteroidetes and Parcubacteria was significantly positively correlated with NH4+-N, while the relative abundance of Acidobacter, Actinobacteria and Firmicutes was significantly negatively correlated with NH4+-N. The relative abundances of Proteobacteria, Bacteroidetes, Elusimicrobia, Parcubacteria and Saccharibacteria were significantly positively correlated with SWW, while the relative abundances of Acidobacter, Actinobacteria, Planctomycotes and Firmicutes were significantly negatively correlated with SWW. The relative abundances of Acidobacterium and Chloroflexi were significantly positively correlated with SBD.