Factors affecting arbuscular mycorrhizal fungi of Chilean temperate rainforests

While arbuscular mycorrhizal (AM) fungi in Chile have been widely documented in agro-ecosystems, there is a knowledge gap regarding AM fungal diversity in Chilean temperate rainforests. AM fungal communities of these forests are affected by several factors: the mountain systems of Chile (Coastal Range or Andes Mountains), the mycorrhizal dominance of the forest (either ectomycorrhizal - EM-or AM), soil chemistry, and altitude. We tested the effects of mountain system, mycorrhizal dominance, soil chemistry, and altitude on AM fungal diversity. From 7,120 AM fungal spores recovered, we identified 14 species, that were found in 41 soil samples collected from 14 plots located in EM and AM forests of the Coastal Range and Andes Mountains of Southern Chile. Mountain system and mycorrhizal dominance affected AM fungal community composition, although neither fungal richness nor abundance were affected. Soil Olsen available P, Ca, Mg, and Na were the edaphic variables structuring AM fungal community composition. There was no relationship between altitude and AM fungal richness, however at high altitudes there was higher abundance. Finally, with this and other studies, a total of 59 AM fungal species, many of which were previously registered exclusively in agroecosystems, are registered on the Chilean AM fungal species list.