Soil Microbial Community Structure and Composition in Chinese Fir Plantations of Different Ages in Fujian, Southeast China

Abstract

ABSTRACT What effects the stand age has on the soil microbial structure and composition remains unclear. The topsoil (0–20 cm) of 3- (YF), 12- (MAF), and 38-year-old (MF) Chinese fir plantations were selected as research objects. We found that the phospholipid fatty acid (PLFA) concentration and OTUs of bacteria and fungi exhibited an uptrend as the stand age increased. Among dominant bacterial and fungal phyla, the relative abundance of Actinobacteria in YF was significantly higher than that in MF and MAF and the relative abundance of Basidiomycota in MF was significantly higher than that in MAF and YF. Interestingly, the relative abundance of three predominant fungal phyla Ascomycota, Basidiomycota, and Zygomycota in MAF were lower than those in MF and YF. The significant difference in the relative abundance of some bacterial phyla (e.g., Ignavibacteriae, Latescibacteria, Nitrospirae, and Tectomicrobia) was also found with stand age, and organic matter, pH, available P, available N, and available K were the main factors for the variances in the biomass and structure of soil microbial communities. These findings showed that considering the shift in the structure and composition of microbial communities might improve our understanding of soil fertility maintenance and sustainable management of these plantations.