Relating Soil Microbial Community Patterns to Regenerated Woody Plant Attributes in a Chinese Fir Plantation Forest

Although previous studies have shown that the patterns of soil microbial communities are significantly associated with plant traits in natural ecosystems, evidence from plantation ecosystems is scarce. Furthermore, there is little knowledge about the linkages between regenerated woody plant attributes, based on the community level, and the diversity and composition of soil microbial communities in plantation ecosystems. Using datasets from a 9 ha permanent plot in a Chinese fir ( Cunninghamia lanceolata (Lamb.) Hook.) plantation forest in subtropical China, we assessed the regulation of the regenerated woody plant community on soil bacterial and fungal community diversity (richness) and composition (β-diversity), after accounting for confounding environmental factors, including the basal area of Chinese fir, edaphic properties, topographic features, and spatial covariates, and then analysed the potential regulatory mechanisms related to plants. Results showed that the regenerated woody plant community conspicuously influenced the diversity and composition of soil microbial communities, despite their relatively low contribution to the total plant basal area. The community composition of both soil bacteria and fungi were strongly coupled with the dissimilarity of regenerated woody plant community composition and basal area. Interestingly, the diversity of soil bacteria and fungi was differently affected by regenerated woody plant attributes. Soil bacterial richness significantly increased with increasing richness of the regenerated woody plants due to the variety substrate input. Whereas soil fungal richness decreased with increasing regenerated woody plant basal area and/or richness due to nutrient competition effect, especially for that of soil pathogens and saprotrophs. Our study provides the first evidence that regenerated woody plants may closely interwove with patterns of diversity and composition of soil microbial communities in plantation forests.