Dynamics in Soil Microbial Community During Forest Succession Depend on Soil Properties in the Karst Region of Southwest China

Abstract

Forest succession can change soil microbial community composition and structure. However, it is unclear how soil microbes respond to forest succession. Using high-throughput sequencing methods, we evaluated the dynamics of soil bacterial and fungal communities during forest succession from shrubland, to secondary forest, to primary forest in the karst region of Southwest China. We found no significant differences in fungal α-diversity with karst forest succession, but the secondary forest had significantly higher bacterial α-diversity than the shrubland and primary forest. Our non-metric multidimensional scaling (NMDS) analysis indicated that the soil bacterial community in the primary forest was close to the shrubland but diverged from the secondary forest, and that the fungal community could be discriminated along forest succession. Also, the microbial co-occurrence network indicated that soil fungi had less but more intense relationships than bacteria in the karst forests. Furthermore, the redundancy analysis (RDA) showed that soil properties, soil microbial biomass, and plant factors drove the dynamics of the soil bacterial community, while soil properties rather than plant factors explained the variation of the soil fungal community along karst forest succession. The different responses of soil bacteria and fungi to forest succession in a karst region informs ecological restoration along forest succession in the karst region.

Keywords: Soil microbial community, Diversity, occurrence, succession, karst forest