Changes in the composition and diversity of bacterial communities 13 years after soil reclamation of abandoned mine land in eastern China

In recent years, the importance of microbial diversity and function to ecosystem restoration has been recognized. The aim of this work was to investigate the diversity and composition of bacterial communities in response to reclamation of a soil subsidence area affected by mining activities. Soil samples were taken in two seasons (December 2012 and July 2013) from a mining reclamation region at the Liuxin national reclamation demonstration area in China and an adjacent coal-excavated subsidence region. 454 high-throughput sequencing technology was used to compare the composition and diversity of bacterial communities in reclaimed soil to that in subsided soil. Predominant phyla in soils were Proteobacteria, Actinobacteria, Acidobacteria, and Planctomycetes, with Proteobacteria making up the majority of the community. Long-term reclamation was found to have significant influences on bacterial communities, and the bacterial community diversity and composition varied between reclaimed and subsided soil. Seasonal fluctuations also contributed to variation in soil bacterial diversity and community composition, but were minor in comparison to effects of reclamation. Differences observed in bacterial community structure and diversity were related to both fertilizer treatment and vegetation, likely through the effects of soil attributes. Soil organic matter and total nitrogen and available potassium were important factors shaping the microbial communities. The reclaimed soil had higher community diversity of bacteria than subsided soil, which suggests that long-term applications of organic amendments and vegetation mixed sowing had significant impacts on soil remediation and microbial diversity.