Mesofauna assemblages on the extraradical mycelium of Pinus greggii roots with three ectomycorrhizal fungi

Background: The extraradical mycelium (ERM) of ectomycorrhizal fungi is a network inhabited by soil mesofauna, mainly collembolans and mites, forming interactions during the fungal life-cycle, from grazing on hyphae to spore dispersal. However, it is still unknown if ERM of ectomycorrhizal fungi could influence the structure of mesofauna assemblages. Objective: To evaluate the abundance and community composition of the mesofauna inhabiting the ERM of Hebeloma mesophaeum, Laccaria laccata and Wilcoxina sp. in Pinus greggii roots. Methods: Mesofauna was collected from the root balls of P. greggii with 80 % of colonization using a washing method. Results and conclusions: An effect was observed due to ERM differences on species richness and species dominance, but not an effect on the abundance and community composition of the mesofauna. However, Wilcoxina sp. presented the lowest species richness and diversity. Fungus-feeding collembolans shaped species-rich assemblages, being isotomid-tullbergid forms the soil-dwelling taxa. Entomobryidae and Hypogastruridae were the most common families on the soil surface, not being found in Wilcoxina sp., and only a few predatory mites of the Mesostigmata and Endeostigmata were found. The ectomycorrhizal mycelium constitutes a trophic niche of the mesofauna and it might be an evolutionary force in structuring species composition and diversity.