Considerazioni fitostoriche sulla zonazione altitudinale della vegetazione di alcuni rilievi dell'Appennino meridionale e della Sicilia

Biogeographia vol. XXX - 2011 (Pubblicato il 23 dicembre 2011) La Biogeografia della Sicilia Considerazioni fitostoriche sulla zonazione altitudinale della Vegetazione di alcuni rilievi dell’Appennino meridionale e della Sicilia FRANCESCO SPADA*, MAURIZIO CUTINI**, BRUNO PAURA*** ‘ Dipartimento di Biologia Ambienmle, Universitd degli Studi di Roma qLa Szzpz'enzzz”, p. [e A. Moro 3, 001 00 Roma (Italy); e—mai[.'fi2zncesc0.5pada @um'roma1 . it q Dipzzrtimento di Biologia Ambientale, Universita‘ degli Studi Roma Fe, z/idle G. Marconi 446, 00146 Roma (Italy); e-mail: cutini@uniroma3. it Uniz/ersitzi degli Studi de[Mo1z'se, via De Sanctis, 86100 Czzmpo/M550 (Italy); e—mzzz'l:fbbos@um'mo[. it Key words: vegetation belts, phytogeography, palaeozonations, Pinm nigm s.l. SUMMARY Current methodological praxis in present day plant ecology and vegetation science makes remarkably difficult to treat topics dealing with floristic changes along gradients, when qualitative aspects, based on biogeographical patterns, are involved. Due to this fact, some outstanding “anomalies” in the altitudinal zonation of vegetation in southern Apennines and in the main islands, have traditionally been neglected or underestimated in their explana- tory capacity for long-term vegetation processes. In this sense, patterns of floristic changes along topographical gra- dients observed in the Southern Italian ridges, from Monti Picentini (Campania) to Etna (Sicily), might be crucial for the interpretation of plant cover’s events and genesis of that part of peninsular Italy. Here, the local ranges of some emblematic species are taken into account. Similarity in their sequences along local “catenas” with analogues in other regions of Southern Eurasia, are here used to infer modes of colonization and altitudinal stratification mirroring major events ofNeogene climatic and paleogeographical changes. In particular the patterns ofaltitudinal clustering of some taxa in Monte Etna seem to be of major relevance for the detection of “fossil” zonations related to ancient environmental scenarios. The local behaviour of Pinus nigrzz s.l., compared to its behaviour in the surrounding massifs and in other S-E European locations, suggests a perva— sive persistence ofLate-Miocene distribution patterns related to the connections with South and Eastern Mediter- ranean landmasses of the emerging Italy of Late-Neogene. PREMESSE L’analisi fitogeografica e cenologica della Vegetazione italiana ha per tradi- zione enfatizzato il fenomeno dell’endemisrno di specie e comunita, in armo— nia con un orientamento “divisivo” della ricerca morfotassonornica degli ulti-