Jingying Hei, Yong Li, Rui Rui, Shu He, Biao Wang, Shu Wang, Xiahong He
Microorganisms are key drivers of soil multifunctionality in agroforestry systems. However, the role of rare and abundant taxa in regulating soil multifunctionality in Sanqi– Pinus armandii agroforestry (SPA) system are not well understood. To address this, monoculture P. armandii (MP) and SPA systems were established herein. High-throughput sequencing was employed to characterize rare and abundant taxa (bacteria and fungi), while soil multifunctionality was assessed by measuring edaphic factors and hydrolytic enzyme activities. The results indicated that Sanqi cultivation significantly increased soil multifunctionality by 10–12%, and also enhanced the α-diversity (4–33%), network complexity (107–262%), and stability (12–19%) of rare taxa in P. armandii forests. Moreover, Sanqi cultivation also enhanced the stochasticity of rare taxa, whereas abundant bacteria and fungi displayed decreased and increased stochasticity, respectively. PCoA and ANOSIM analyses revealed that Sanqi cultivation, rather than ecological niches, exerted a dominant influence on abundant and rare microbial communities. Additionally, both abundant taxa (Chloroflexi, Basidiomycota) and rare taxa (Proteobacteria, Basidiomycota) exhibited significantly greater relative abundances in the SPA system. PLS-PM and random forest indicated that soil multifunctionality was directly impacted by the α-diversity and network complexity of rare taxa. Together, our results highlight the indispensable role of rare taxa in the SPA system, offering new insights and practical implications for the sustainable optimization of agroforestry ecosystems. • Sanqi cultivation increases soil multifunctionality in P. armandii soil. • α-diversity, network complexity and stability of rare taxa are notably increased. • Rare taxa stochasticity are raised following Sanqi cultivation. • Rare taxa network complexity and α-diversity directly affects soil multifunctionality.