Symbiotrophs dominate rhizosphere soil fungal community stability of the Cathaya argyrophylla

Cathaya argyrophylla is an ancient and endangered pine tree unique to China and is classified as an endangered species due to climate deterioration and glacier action, etc. However, there is limited research of its rhizosphere microbiome and this information is essential for potential modifications of its habitat to allow for its continued survival. The current study collected rhizosphere soil from the two remaining C. argyrophylla nature reserves in Hunan Province and explored the changes in community characteristics of rhizosphere soil fungal functional groups (symbiotrophs, saprotrophs and pathotrophs). We evaluated their impact on fungal community stability using the average variation degree (AVD). The soil fungal community stability in the Chengbu area was significantly higher than that in the Chenzhou area (F = 6.34, P < 0.05) and this was closely related to the significant differences in alpha- (F-Shannon = 14.85, F-Chao1 = 12.97, P < 0.01) and beta-diversity of symbiotic fungal communities. We also found that the network stability (r = 0.741, P < 0.01) and niche breadth (r = 0.598, P < 0.05) for symbiotrophs were significantly correlated with AVD. Additionally, Russula and Mortierella were core symbiotrophs shared in the rhizosphere soil of C. argyrophylla. Overall, we found that symbiotrophs were particularly important for soil fungal community stability in C. argyrophylla habitats and identified core taxa involved in these processes. This work provides a reference basis for policies and management measures to protect the ecosystem services of the C. argyrophylla community from the perspective of the soil microbiome.