DISCUSSION
Through a two-factor greenhouse-controlled experiment, we demonstrated that high AMF diversity increased ecosystem multifunctionality. When subjected to multiple GCFs, ecosystem multifunctionality under high AMF diversity was significantly higher than that under low AMF diversity and any mono-AMF treatment, indicating complementarity among different AMF species might help maintain ecosystem multifunctionality under the increasing GCF numbers. In addition, the advantages of high AMF diversity in promoting plant photosynthesis and biomass remained consistent across all experimental conditions. This suggests that while ecosystem multifunctionality may be influenced by an interplay of factors, the positive impact of AMF diversity on plant productivity is robust and enduring.