Auteuil Fungal Carns Bet The volume of soil exploited can be increased by the elaboration of root hairs (left), and by symbiotic associations with ectomycorrhizal fungi (centre) or vesicular-arbuscular mycorrhizae(right)• The volume of soil exploited can be increased by the elaboration of root hairs (left), and by symbiotic associations with ectomycorrhizal fungi (centre) or vesicular-arbuscular mycorrhizae (right)