Arbuscular mycorrhizal fungi equalize differences in plant fitness and facilitate plant species coexistence through niche differentiation

Mycorrhizal fungi are essential to the establishment of the vast majority of plant species but are often conceptualized with contradictory roles in plant community assembly. On one hand, host-specific mycorrhizal fungi may allow a plant to be competitively dominant by enhancing growth. On the other, host-specific mycorrhizal fungi with different functional capabilities may increase nutrient niche partitioning, allowing plant species to coexist. To resolve the balance of these two contradictory forces, we used a controlled greenhouse study to manipulate the presence of two main types of mycorrhizal fungi, ectomycorrhizal fungi (EMF) and arbuscular mycorrhizal fungi (AMF) and used a range of conspecific and heterospecific competitor densities to investigate the role of mycorrhizal fungi in plant competition and coexistence. We find that the presence of AMF equalizes fitness differences between plants and stabilizes competition to create conditions for host species coexistence. Our result..., , , # Data from: Arbuscular mycorrhizal fungi equalize differences in plant fitness and facilitate plant species coexistence through niche differentiation

**Authors:** Claire E. Willing, Joe Wan, Jay J. Yeam, Alex M. Cessna, Kabir G. Peay

 Authors for correspondence:

Claire E. Willing ([[e-mail]](mailto:[e-mail]))

Kabir G. Peay ([[e-mail]](mailto:[e-mail]))

 Access this dataset on Dryad: [https://doi.org/10.5061/dryad.rxwdbrvjb](https://doi.org/10.5061/dryad.rxwdbrvjb)

# Description of the data and file structure

Where data is missing, values are reported as NA. This includes where data was never measured due to sample missingness. For values that were measured beyond machine detection limits, these are also listed as NA. Units for all variables are reported below for each specific file type.

| File Name | File description ...