Analysis of the Soil Bacterial Community Structure and Its Relationship with Soil Properties in Different Successive Rotation Cunninghamia lanceolata Plantations

In order to explore the diversity of community structure of soil bacteria in different algebras of Cunninghamia lanceolata plantation and its correlation with soil physical and chemical properties. On the basis of determining the physical and chemical properties of different algebraic C. lanceolata soils, high-throughput sequencing technology was used to determine the number of soil bacteria and the diversity of community structure, and the correlation among the number of soil bacteria, the diversity of community structure and the physical and chemical properties of soil was analyzed. The results showed that the physical and chemical properties of soil pH, total carbon, total nitrogen, and total porosity volume showed a downward trend, except for soil bulk density, as the successive algebras increase. The dominant species of soil bacteria in different algebraic C. lanceolata plantations are Acidobacteria, Proteobacteria, Planctomycetes, and Chloroflexi at the phylum classification level. The main dominant species are DA052, Acidobacteria, α-Proteobacteria, and Planctomycetes at the class classification level. The main dominant species at the order classification level are DA052 uncultured bacterium, Acidobacteriales, Solirubrobacterales, Rhizobiales, and Planctomycetales. With the increase of crotations of continuous planting, the relative abundance of Acidobacteria and DA052 decreased gradually, while the relative abundance of Proteobacteria, Acidobacteria, Solirubrobacterales and Rhizobia increased gradually. The community index Ace of the soil bacterial community and the community index Chao1 were the highest in the 1^st generation C. lanceolata plantation. Soil TK, TC, TN, TP, pH, capillary pore volume, water content, and soil bulk density have a greater effect on the relative abundance of major bacteria bacterial groups are at different levels of classification. The community index Ace, community index Chao1, community index Simpson, and community index Shannon were significantly correlated with soil bulk density, TP, TN, TC, water content, non-capillary pore volume, and total porosity volume.