Structure and function of soil bacterial communities in the monoculture and mixed plantation of and in southern subtropical China.

Establishing monoculture of native broadleaved tree species and mixed coniferous broadleaved plantations is the tendency for forest management in subtropical China. The variations of structure and function of soil bacterial community in monoculture and mixed tree plantations are still not clear. We examined soil bacterial community structure and function under different soil layers (0-20, 20-40 and 40-60 cm) in three planted forests, including broadleaved coniferous and their mixed plantation, in south subtropical China, using 16S rRNA gene high-throughput sequencing and PICRUSt prediction. The results showed that soil bacterial community structure of mixed plantation and plantation were similar but being significant different from that in plantation. The diversity, biological pathways metabolic function, and nitrogen cycling function of soil bacterial community in plantation were lower than those in plantation and mixed plantation. Soil total nitrogen, nitrate nitrogen and C/N were the main factors driving the variations of soil bacterial community structure and function among different forest types. Our results suggested that the mixed plantation of and is better than plantation in this area in terms of soil bacterial community structure and function.