Arbuscular mycorrhizal fungi modulate soil microbial network complexity via microbial interactions in different vegetation ecosystems

Arbuscular mycorrhizal fungi (AMF) establish symbiotic partnerships with diverse plant roots, profoundly shaping the structure of soil microbial communities. However, the complex mechanisms governing the influence of AMF on microbial interactions remain unclear. The aim of this research was to elucidate the dynamics of AMF community assembly across distinct ecosystems (grass, shrub, and forest) on Luya Mountain and the related implications for multidomain soil microbial network structures. AMF community diversity, composition, and microbial network structure varied significantly among the vegetation types. The results revealed that the inclusion of AMF in microbial networks substantially simplified network complexity in shrub and forest ecosystems. Stochastic processes within the AMF community increased the complexity of the microbial networks. Notably, AMF enhanced the robustness of soil microbial networks while reducing their vulnerability, underscoring their role in increasing network stability. Moreover, the inclusion of AMF in the networks altered the composition and reduced the quantity of keystone taxa, indirectly fostering trophic cascades mediated by protozoa and nematodes, thereby modulating the complexity of the soil multidomain networks. The impact of AMF on bacterial network structure was significantly greater than that on other microbial network structures. Taken together, these findings provide critical insights into the mechanisms through which AMF communities influence soil microbial networks while offering a scientific foundation for ecosystem management and restoration practices.