Exploring the diversity and dynamic of bacterial community vertically distributed in Tongguling National Nature Reserve in Hainan Island, China

National nature reserves are important for preserving ecological resources and constructing national ecological security barriers. Tongguling National Nature Reserve (TNNR) is known for its unique tropical island ecosystem and abundant biological resources. This study was conducted to characterize and compare its bacterial community diversity and composition in soils from 10, 20, and 30 cm in depth using high-throughput sequencing of 16S rDNA genes. We found that soils from 20 cm had the highest diversity and might serve as a “middle bridge” to the dynamic distribution between the 10- and 30-cm soil samples. The diversity pattern indicated that the main abundant groups varied distinctly and significantly among soils of different depths. Moreover, Chloroflexi was the most dynamic group in TNNR soils, together with another abundant but rarely reported group, Verrucomicrobia, which greatly enhanced the microbial diversity of TNNR soils. Overall, the results of this study emphasize the urgent need for greater understanding of bacterial community variations in response to human activities and climate change.