Ectomycorrhizal diversity enhances growth and nitrogen fixation of Acacia mangium seedlings

► The effect of multiple ectomycorrhizal inoculations on A. mangium growth was assessed. ► Increasing the amount of mycorrhizal propagules and diversity enhances plant growth. ► This ectomycorrhizal effect is dependent on the functioning of nitrogen fixation. ► Multiple fungal symbiont inoculation could optimize forest plantation performance.