Phylogenetic Structure of Soil Bacterial Communities along Age Sequence of Subtropical Cunninghamia Lanceolata Plantations

Despite increasing investigations having studied the changing patterns of soil microbial communities along forest plantation development age sequences, the underlying phylogenetic assemblages are seldom studied for microbial community. Here, the soil bacterial taxonomic and phylogenetic diversity as well as the phylogenetic structure were examined to elucidate the community diversity and assembly in three typical ages (young, middle and mature) of Cunninghamia lanceolata plantations, a dominant economic tree species in southern China. Results indicated that the soil bacterial phylogenetic not taxonomic diversity increased with the increasing in stand age. The bacterial community composition differed significantly among the young, middle and mature plantations. Phylogenetic signals showed that bacterial communities were phylogenetically clustered and structured by environmental filtering in all studied plantations. In mature plantation, the effect of environmental filtering becomes stronger and bacteria taxa tend to intraspecific interact more complexly as characterized by co-occurrence network analysis. This suggests that ecological niche-based environmental filtering could be a dominant assembly process that structured the soil bacterial community along age sequences of Cunninghamia lanceolata plantations.