Lichens and lichenicolous fungi onTaxus baccataL andIlex aquifoliumL in Sardinia (Italy)

Ilex aquifoliumL. andTaxus baccataL. are woody species which grow, often together, in humid and fresh mountain stations. In Sardinia, as in other Mediterranean countries, their ecological value is particularly high because they represent residuals of primeval forest that is almost disappeared for causes linked also to human activities. Lichens are a group of organisms which constitute a high percentage of the biodiversity in every site and they colonize the trees with peculiar species and growth forms. A study targeted on lichens growing onT.baccataandI. aquifoliumseems not present until nowadays. The present study aims to extend the knowledge on Sardinia epiphytic lichens focusing on the ones growing on these two kinds of trees. The research was concentrated mainly on holly because it is more common than yew. Bibliographic material was collected and surveys were made in 23 localities for holly and 4 localities for yew. Descriptions of the ecological, geological and climatic features of the sampling sites and of the lichen component in each of them are provided. On holly 140 taxa were found, whereas 55 on yew, but the localities analyzed were less. Among them several species are particularly rare and 5 new records for Sardinia were found. Statistical elaborations were made to discover possible relationships between number of taxa collected and circumference of trees, altitude and climatic features of the sites.