Convergence of root ectomycorrhizal fungal communities across Pinaceae developmental stages in temperate forests in northeastern China

Ectomycorrhizal fungi (EMF) are crucial for the development of temperate forests. We conducted a field study via a "space-for-time" approach to investigate root EMF succession across saplings, juveniles, and adults of four Pinaceae species in northeastern China. By high-throughput sequencing of the fungal internal transcribed spacer 2 region, we cataloged 1,641 EMF amplicon sequence variants. As Pinaceae matured, EMF alpha diversity notably increased, while their Bray-Curtis dissimilarity significantly decreased. A random forest algorithm identified stage-specific taxa, marking the age-related transition from structural divergence to similarity in root EMF communities. EMF genera <i>Amphinema</i> and <i>Suillus</i> dominated in Pinaceae saplings, while <i>Piloderma</i>, <i>Russula</i>, <i>Sebacina</i>, and <i>Tomentella</i> were more common in Pinaceae adults. Co-occurrence network analysis demonstrated greater interconnectivity among EMF taxa in adults than in their younger counterparts. These findings suggest that root EMF community dynamics are synchronized with the recruitment and development of Pinaceae species in temperate forests.