The effects of ectomycorrhiza on Aleppo pine seedlings' ability to endure drought and inter-plant competition

Abstract

Seedling establishment under natural conditions is often limited by numerous interacting factors. We tested the combined effects of drought, herbaceous competition, and ectomycorrhizal fungi (EMF) on the growth and shape of Aleppo pine seedlings and their associated EMF community. EMF inoculum significantly increased seedlings’ height, biomass, and the number of side branches. However, under either competition or drought, the effect of EMF on seedling biomass and height was greatly reduced, while the effect on shoot branching was maintained. All plants were strongly dominated by Geopora, a fungal genus known to inoculate seedlings in dry habitats. Under a combination of drought and competition, EMF had no influence on plant growth and shape. This discrepancy highlights the complexity of the benefits provided to seedlings by EMF under ecologically relevant conditions.