EFFECT OF CONVERTING NATURAL FORESTS TO PLANTATIONS ON THE SOIL BACTERIAL DIVERSITY IN A SUBTROPICAL MOUNTAINOUS AREA: CASE STUDY IN SOUTHERN CHINA

Although soil bacteria regulate biogeochemical processes, little is known about the response of their distribution and abundance to land-use changes in the subtropical region. In the present study, soil samples from four natural forests and two agricultural plantations were collected from a subtropical mountainous area of southern China. A high-throughput sequencing approach was applied to explore the soil bacterial community composition and diversity. The results showed that dominant bacterial taxa ( such as Acidobacteria, alpha-proteobacteria, gamma-proteobacteria, and Planctomycea), which accounted for >41% of the bacterial sequences, decreased with the conversion of natural forests to plantations. Structural equation modeling and canonical correspondence analysis indicated that the bacterial community and diversity responded to the decrease in soil carbon and nitrogen contents and the increase in available soil phosphorus content. Multiple statistical analyses, including hierarchical cluster, response ratio, and least discriminate analysis effect size, revealed that the community-level patterns were caused by the responses of a few taxa, particularly Rhizobiales, Bacilli, Burkholderiales, and Nitrospiraceae, which are the bacterial indicators of soil nutrient status. Our findings will help better understand the response of soil bacterial communities to reforestation and agricultural management during land-use changes in the subtropical region.