Soil Bacterial Communities In Native and Regenerated Perhumid Montane Forests.

   Forest management often results in changes in soil properties and its microbial communities. In the present study, differences in the soil bacterial community caused by forest management practices were characterized using small subunit (SSU) ribosomal RNA (rRNA) gene clone libraries. The communities were from a disturbed Chamaecyparis (DCP) forest subjected to harvesting of snags and downed logs, a secondary Chamaecyparis (SCP) plantation subjected to harvesting of old-growth trees, and a secondary cedar plantation (SCD). These forests were compared to a nearby native Chamaecyparis (NCP) forest in a perhumid montane ecosystem. At this locality, the elevation ranges from 1500 m to 2100 m, the mean annual precipitation is over 4000 mm, the mean annual temperature is about 12 °C, and the soil pH is <4. The phyla Acidobacteria and Proteobacteria predominated among the three disturbed forest soil communities. Based on several diversity indices and rarefaction curves, the diversity of the SCD community was higher than that in the DCP soils. The diversity of the community in SCP soils was intermediate. The bacterial diversity of the NCP community was lower than those in three disturbed forest soils. Analysis of molecular variance also revealed that the bacterial community in SCD was significantly different from those in the three Chamaecyparis forest soils. Some of the abundant OTUs were also distributed significantly different among the four forest soils. Comparing to the three disturbed forest soil communities, the NCP community was dominated by Proteobacteria, which accounted for more than half of the community. These results suggest that the disturbance of forest harvesting and tree species conversion influence the composition of bacterial community between natural and disturbed forests and increase the diversity of the disturbed forest soil community.