Genetic diversity and community structure of soil bacteria in Chinese fir plantations

Abstract

To explore the diversity of soil bacteria and changes in the bacterial community structure of Chinese fir plantations of different generations and developmental stages, the genetic diversity of soil bacteria was studied using the 454 sequencing technology. The results showed that the bacterial genetic diversity and community structure of Chinese fir plantation plots under monoculture planting and rotation planting practices were as follows: the Shannon diversity indices of first-generation young plantation of Chinese fir plantations (FYC), second-generation young plantation (SYC), and third-generation young plantation (TYC) initially decreased and then increased to 8.45, 8.1, and 8.43, respectively. Due to different management and tending measures, the phyla showing considerable differences in relative abundance were Cyanobacteria, Nitrospirae, Fibrobacteres, Thermotogae, and Planctomycetes. The bacterial genetic diversity and community structure of Chinese fir plantations at different developmental stages were as follows: the bacterial diversity and the number of operational taxonomic units (OTUs) decreased with increasing forest age; with the increasing forest age of Chinese fir, the bacteria with considerable differences in the relative abundance were Burkholderiales, Xanthomonadales, Ktedonobacteria, Nitrosomonadales, Anaerolineae, and Holophagae. The predominant bacteria of the Chinese fir plantations were Acidothermus, Bradyrhizobium, Lactococcus, Planctomyces, Sorangium, and Bryobacter.