Abstract: Aim This study investigates the variation in arbuscular mycorrhizal fungal (AMF) community structure and its driving factors in the alpine wetlands of the Yellow River Source Region within Sanjiangyuan National Park, with the aim of providing a scientific basis for ecosystem conservation and sustainable management in this area. Methods Alpine riverine wetlands and alpine swamp wetlands in the Yellow River Source Region were selected as the study objects. An integrated approach combining field investigation and sampling, laboratory analyses, and high-throughput sequencing was employed to systematically examine AMF community structure across wetland types and dominant plant species, and to identify the key factors driving community variation. Important findings Vegetation cover was significantly lower in swamp wetlands than in riverine wetlands, whereas soil electrical conductivity, total carbon, and total nitrogen were significantly higher. In total, 2,799 amplicon sequence variants (ASVs) belonging to the phylum Glomeromycota were identified and classified into 9 families and 10 genera, with Claroideoglomus and Glomus being the main predominant taxa. AMF α-diversity did not differ significantly between wetland types, whereas β-diversity showed significant differences. Variance partitioning analysis (VPA) indicated that wetland type and abiotic factors jointly explained 4.67% of community variation, with abiotic factors alone accounting for 3.39%, which was higher than the independent effect of wetland type (1.04%). Likewise, plant species and abiotic factors together explained 5.00% of AMF community variation, with the independent contribution of abiotic factors (2.04%) being slightly higher than that of plant species (1.38%). Mantel tests and canonical correspondence analysis (CCA) further demonstrated that plant richness, soil moisture, soil nutrient contents, and elevation were the key drivers of AMF community structure. Conclusion In summary, AMF community structure in the alpine wetlands of the Yellow River Source Region is primarily driven by abiotic factors, while also being synergistically influenced by biotic components. These findings provide important scientific support for the development of targeted wetland ecological management strategies.

Key words: Alpine wetland, arbuscular mycorrhizal fungi, community diversity, driving factors