The ectomycorrhizal community in Mediterranean old-growth Quercus ilex forests along an altitudinal gradient

The Mediterranean coastal region is considered a “hot spot” of both biodiversity and climate change, as global average air temperatures and atmospheric CO2 concentrations are increasing with subsequent impacts on regional precipitation patterns. The main goal of this study, performed in the largest Mediterranean holm oak forests (Sardinia Island, Italy), was to verify whether the vitality of root tips and the composition of the ectomycorrhizal community of holm oak change with the altitudinal gradient. The results demonstrated that the altitude does not significantly affect the vitality and the degree of ectomycorrhization of the root tips, while significant differences were observed in the ectomycorrhizal community composition, correlated with both the altitude and the Southward exposition of the root systems, both associated to the increase of xeric and drought conditions at the soil level. This study should help to integrate the understanding of forest ecology and forecast modelling, to improve the management strategies of the Mediterranean oak forests in the future.