不同林龄华北落叶松外生菌根真菌多样性研究OA

[Objectives]This study aimed to elucidate the structural differentiation and environmental de-terminants of ectomycorrhizal(ECM)fungal communities in Larix principis-rupprechtii plantations at differ-ent stand ages in the Daqingshan Mountains of northern China.[Methods]Ectomycorrhizal fungal com-munities were characterized using Illumina MiSeq high-throughput sequencing.Community diversity,in-cluding taxonomic and phylogenetic diversity,was quantified,and multivariate statistical analyses were employed to identify key environmental drivers in relation to soil physicochemical properties.[Results]Basidiomycota consistently dominated the ECM community across all stand ages,yet dominant taxa shif-ted along the chronosequence:Tricholoma was enriched in young stands;Wilcoxina and Amphinema were significantly enriched in mature stands;while Tricholoma re-emerged as the dominant genus in mature de-graded stands.Species diversity exhibited a"rise-then-decline"trend,with mature stands showing the highest species richness,Chao,Shannon,and phylogenetic diversity(PD),and degraded stands showing the lowest.β-diversity and ordination analyses indicated clear separation among the three stand ages and strong species turnover,reflecting the combined effects of niche differentiation and environmental filtering during succession.Network analyses further demonstrated that mature stands exhibited higher node de-gree and modularity,suggesting greater potential functional redundancy and enhanced structural stability.Environmental interpretation identified soil pH and total phosphorus(TP)as the principal controlling factors:pH generally exerted a negative effect on diversity,while TP was positively associated with com-munity composition and phylogenetic breadth.These results highlight the coupled regulation pf soil acidity and phosphorus availability was a key regulatory mechanism governing ECM fungal assembly.[Conclu-sion]Stand age reshapes soil pH and phosphorus availability,driving age-related shifts and stage-specific enrichment of ECM fungal taxa along the successional gradient.The mature stage represents a critical window with maximal phylogenetic breadth and network stability for sustaining plantation ecosystem func-tions.From a management perspective,threshold-based soil amelioration and phosphorus regulation fo-cusing on pH and TP,together with monitoring of phylogenetic diversity and indicator taxa,are recommen-ded to enhance productivity,nutrient cycling,and carbon sequestration.For degraded stands,priority should be given to restoring microenvironmental conditions and soil nutrient availability to recover network complexity and functional redundancy.