Biogeographic issues related to the syntaxonomy of Quercus cerris and Q. frainetto forests in Italy.

We have compiled a data set of 2900 relevés of Q. cerris forests and treated it with multivariate analysis procedures. Although the results of the cluster analysis only partially reflect the current major syntaxonomic frameworks, the oak forests of southern Italy show a clear floristic identity and autonomy. This evidence is consistent with the proposal to divide the subacidophilous oak forests of the Italian peninsula into two geographically vicariant alliances, similar to what has already been reported in the EVC for the Balkan Peninsula, with a “northern” Quercion frainetto and a “southern” Geranio-Quercion frainetto.