Determining fungal niches for unobservable and unculturable taxa belowground, such as arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) fungi, remains one of the largest challenges in microbial ecology. Species distribution models (SDMs) can provide hypotheses for drivers of mycorrhizal fungal niches. Using SDMs, AM fungi had larger ranges than EM fungi that varied with host associations and climate, but not soil resources. EM fungal distributions were consistently affected by climate and dispersal limitation. If AM fungi are more host specific than expected and EM fungi are dispersal limited, this warrants reconsideration of how their distributions will respond to future global change.
