Data from: Mycorrhizal symbiosis increases the benefits of plant facilitative interactions

The diversity of pathways through which mycorrhizal fungi alter plant
coexistence hinders the understanding of their effects on plant-plant
interactions. The outcome of plant facilitative interactions can be
indirectly affected by mycorrhizal symbiosis, ultimately shaping
biodiversity patterns. We tested whether mycorrhizal symbiosis enhances
plant facilitative interactions and whether its effect is consistent
across different methodological approaches and biological scenarios. We
conducted a meta-analysis of 215 cases (involving 21 nurse and 29
facilitated species), in which the performance of a facilitated plant
species is measured in the presence or absence of mycorrhizal fungi. We
show that mycorrhizal fungi significantly enhance plant facilitative
interactions mainly through an increment in plant biomass (aboveground)
and nutrient content, although their effects differ across biological
contexts. In semiarid environments mycorrhizal symbiosis enhances plant
facilitation, while its effect is non-significant in temperate ecosystems.
In addition, arbuscular but not ecto-mycorrhizal (EMF) fungi significantly
enhances plant facilitation, particularly increasing the P content of the
plants more than EMF. Some knowledge gaps regarding the importance of this
phenomenon have been detected in this meta-analysis. The effect of
mycorrhizal symbiosis on plant facilitation has rarely been assessed in
other ecosystems different from semiarid and temperate forests, and rarely
considering other fungal benefits provided to plants besides nutrients.
Finally, we are still far from understanding the effects of the whole
fungal community on plant-plant interactions, and on plant species
coexistence.