Coexistence process and driving factors of arbuscular mycorrhizal fungi in urban green soil under heavy metal stress

The response of arbuscular mycorrhizal fungi (AMF) community assembly in urban green space soils to heavy metal (HM) pollution remains underexplored. In this study, 60 soil samples were collected from green spaces across Zhengzhou, a rapidly urbanizing city located in central China. Soil edaphic factors and levels of five HMs were measured, alongside the sequencing of AMF communities. Our results indicated that all HMs exceeded Henan soil background levels, with pollution levels increasing with greater distance from the urban center. Furthermore, deterministic processes governed the assembly of specialist AMF communities, while stochastic processes dominated in generalists. Iron (Fe) and zinc (Zn) served as key drivers of AMF community structure. These findings highlight the significant role of HM pollution in shaping AMF community assembly processes in urban green spaces. By enhancing our understanding of how HM pollution affects AMF ecological dynamics, strategies can be informed for maintaining and improving ecosystem functionality in urban green areas.