Phytosociological characterization of the Celtis tournefortii subsp. aetnensis microwoods in Sicily

A work on the Celtis tournefortii subsp. aetnensis vegetation, endemic species located in disjointed sites in the Sicilian inland, is here presented. It forms microwoods with a relict character established on screes and detrital coverages, on a variety of lithological substrates (volcanics, limestones, quartzarenites). Based on the phytosociological analysis carried out in the territory, these vegetation aspects are framed in the alliance Oleo-Ceratonion, within which a new association (Pistacio terebinthi-Celtidetum aetnensis) is described, in turn diversified in the following subassociations: a) typicum subass. nova, on detrital calcareous cones of the north-western part of Sicily, in the Palermo province (Rocca Busambra, Pizzo Castelluzzo and northern slopes of Pizzo Telegrafo); b) phlomidetosum fruticosae subass. nova, typical of carbonate megabreccias, on the most xeric southern slopes of Pizzo Telegrafo (Caltabellotta territory, Agrigento province); c) artemisietosum arborescentis subass. nova, typical of quartzarenitic outcrops on the Nebrodi Mts. inland (Cesarò territory, Messina province); d) rhamnetosum alaterni subass. nova, widespread on cracked lava flows of the western side of Mount Etna (Catania province)