Unveiling unique endemic associations. A contribution to the knowledge of chasmophytic vegetation on the Sorrento Peninsula and Picentini Mountains

Sorrento Peninsula and the Picentini Mountains are rich in local endemics and have been well studied taxonomically, but their vegetation, particularly cliff plant assemblages, remains poorly known. This paper presents phytosociological insights on cliff-dwelling communities in these areas. We conducted 28 relevés (8 previously published) and used multivariate analyses to classify them. The bioclimatic context was analyzed using Rivas-Martínez indexes and compared with other Central Mediterranean rock vegetation. We identified three clusters classified into one association and two sub-associations: Globulario neapolitanae-Loniceretum stabianae typicum; Globulario neapolitanae-Loniceretum stabianae globularietosum neapolitanae subass. nova; and Diantho virginei-Seselietum polyphylli ass. nova. This vegetation is referred to a new alliance, Lonicerion stabianae all. nova, characterized by an intermediate Mediterranean, temperate, and weakly continental climate. The endemic cliff vegetation in these areas suggests a distinct phytogeographical sector within the Italian Peninsula.