Dinamica delle comunità ectomicorriziche in sugherete della Sardegna

The aim of the research was to detect the variations in structure and composition of the ectomycorrhizal fungal communities in several cork oak stands that differed in lithologic substrate (granitic, basaltic, trachytic) and management systems. This survey was carried out in order to implement generalizable models of the dynamics of ectomycorrhizal communities in ecosystems dominated by cork oak trees. Overall of nine cork oak stands, representative of 75% of the natural cork oak stands, 40% of the grazed and 60% ploughed that occur in Sardinia were investigated. Two transects were delimited in each cork oak stand and soil samples were collected to study the ectomycorrhizal community in spring and autumn respectively. In total 82.333 ectomycorrhizal tips were isolated and 185 Operative Taxonomic Units (OTUs) were characterized based on morpho-anatomic analysis. 149 of them were identified on the basis genetic analysis. Both structure and composition of the ectomycorrhizal community were significantly influenced by the sampling season, management system and lithologic substrate: particularly the structure was influenced by the management system and season, whereas the composition in the OTUs by the management and lithologic substrate. The latest result have allowed to individuate guilds of fugal species that characterize the cork oak stands investigated.