A Phytosociological study of the deciduous oak woods of Sardinia (Italy)

We present here the results from a phytosociological and synchorological study of the deciduous oak woods of Sardinia. This vegetation analysis has allowed the individuation of three new associations:Lonicero implexae-Quercetum virgilianae, Ornithogalo pyrenaici-Quercetum ichnusaeandGlechomo sardoae-Quercetum congestae. TheLonicero implexae-Quercetum virgilianaeassociation includes the woods on calcareous substrata spread throughout Northern Sardinia, which can occasionally be found in southern areas; the first of these are rich in mesophilous species and are attributed to the subassociationcyclaminetosum repandi, while the others are referred toquercetosum virgilianae. TheOrnithogalo pyrenaici-Quercetum ichnusaeassociation, more widely distributed in Central-Northern Sardinia, includes theclimatophilous deciduouswoods that are found on lithological substrata of a non-carbonatic nature, and in particular, on andesites, trachytes and metarenites. The typical aspect is referred to the subassociationcytisetosum villosi, while the subassociationilicetosum aquifoliiincludes the more mesophilous woods on basaltic substrata. TheGlechomo sardoae- Quercetum congestaeassociation always includes the woods found on the non-carbonatic substrata in the higher altitude areas with an oceanic pluviseasonal temperate bioclimate. Of this, the subassociationquercetosum congestae, on the granite areas, andoenanthetosum pimpinelloidis, on those metamorphic and of basalt, are proposed. At the higher hierarchical levels, the associationLonicero implexae-Quercetum virgilianaeis referred to the endemic Sardinian-Corsican suballianceClematido cirrhosae-Quercenion ilicis, of the allianceFraxino orni-Quercion ilicis, while for the other associations the new suballiancePaeonio morisii-Quercenion ichnusae, (holotypus:Glechoma sardoae-Quercetum congestaeass. nova) particular to the Sardinian biogeographic subprovince, is proposed, of the alliancePino calabricae-Quercion congestae, the orderQuercetalia pubescentipetraeae, and the classQuerco roboris-Fagetea sylvatica.