Phytosociological and distributional researches on the grasslands of the class Lygeo-Stipetea in western Sicily.
- Autori: Caldarella, O.; LA ROSA, A.; Gianguzzi, L.
- Anno di pubblicazione: 2009
- Tipologia: Proceedings (TIPOLOGIA NON ATTIVA)
- Parole Chiave: Grasslands, Lygeo-Stipetea, Phytosociology, Vegetal landscape, Sicily
- OA Link: http://hdl.handle.net/10447/37846
The thermo and meso-xerophilous pseudo-steppic vegetation is widespread in the driest areas of the Mediterranean Region and is primarily referred at the class Lygeo-Stipetea. This sintaxon includes communities dominated by several hemicryptophytes, which are also associated to some geophytes and therophytes. In Sicily this vegetation is distributed from sea level to 1300-1400 m, on different substrates (limestone, gypsum, schists, calcarenites, conglomerates, etc.), within the thermo and mesomediterranean belt dry to subhumid. Principally, are secondary grasslands used for grazing, localized on previously deforested areas, where the periodic burnings play a fundamental role in maintaining these habitats. In fact, the decline of the grazing activities gave origin to dynamic processes with consequential modifications at the physiognomical and structural level, producing the gradually recovery of the climactical forest. In the ecological succession, grasslands represent one of the more degraded subseral stages of the maquis of Pistacio-Rhamnetalia alaterni and of the climactical forest of Quercetalia ilicis. This paper presents the preliminary results of a phytosociological and distributional research on some grassland formations of north-western Sicily spread from coastal to mountain areas (Palermo Mountains, Madonie Mountains, Sicani Mountains, etc.). These aspects are included in the orders Lygeo-Stipetalia (alliance Moricandio-Lygeion) and Hyparrhenietalia hirtae (all. Hyparrhenion hirtae and Avenulo-Ampelodesmion mauritanici), referred to several associations, many of which known in literature (Helictotricho convoluti-Ampelodesmetum mauritanici, Hyparrhenietum hirto-pubescentis, Pennisetum setacei-Hyparrhenietum hirtae, Asteretum sorrentini, Lygeo-Lavateretum agrigentinae, Lygeo-Eryngietum dichotomi ecc.) (1, 2). The same coenoses are sometimes very common in the territory, as in the case of the grasslands dominated by perennial grasses (Ampelodesmos mauritanicus, Hyparrhenia hirta, Pennisetum setaceum) that colonize the deforested slopes of most reliefs, characterizing large areas of the Sicilian landscape. Other formations show a scattered distribution, as some pioneer communities dominated by Stipa sp. pl., in the mountain ridges (3), and by Aster sorrentini in clayey badlands. 1) MINISSALE P., 1995. Coll. Phytosoc. 21 (1993): 615-652. 2) BRULLO S., GIUSSO DEL GALDO G., MINISSALE P., SIRACUSA G., SPAMPINATO G., 2002. Boll. Acc. Gioenia Sci. Nat. Catania 35 (361): 325-359. 3) CALDARELLA O., GIANGUZZI L., 2007. Atti del 102° Congresso Soc. Bot. Ital. Palermo 26-29 Settembre 2007, p. 402.