Abstract
BACKGROUND: The bacterial community of forest soils is influenced by environmental disturbance and/or meteorological temperature and precipitation. In this study, we investigated three bacterial communities in soils of a natural hardwood forest and two plantations of conifer, Calocedrus formosana and Cryptomeria japonica, in a perhumid, low mountain area. By comparison with our previous studies with similar temperature and/or precipitation, we aimed to elucidate how disturbance influences the bacterial community in forest soils and whether bacterial communities in similar forest types differ under different climate conditions. RESULTS: Analysis of 16S ribosomal RNA gene clone libraries revealed that Acidobacteria and Proteobacteria were the most abundant phyla in the three forest soil communities, with similar relative abundance of various bacterial groups. However, UniFrac analysis based on phylogenetic information revealed differences of bacterial communities between natural hardwood forest and coniferous plantation soils. The diversities of bacterial communities of the replanted Calocedrus and Cryptomeria forests were higher than that in natural hardwood forest. The bacterial diversity of these three forest soil were all higher than those in the same forest types at other locations with less precipitation or with lower temperature. In addition, the distribution of some of the most abundant operational taxonomic units in the three communities differed from other forest soils, including those related to Acidobacteria, α-, β- and γ-Proteobacteria. CONCLUSIONS: Reforestation could increase the bacterial diversity. Therefore, soil bacterial communities could be shaped by the forestry management practices and climate differences in warm and humid conditions.