Ambiente e clima della Sicilia durante gli ultimi 20 mila anni

Abstract

Environment and Climate in Sicily over the last 20, 000 years. (IT ISSN 0394-3356, 2010). A series of recent studies shed light on the central Mediterranean, and Sicily, climate and environment, starting from the last glacial maximum (about 20 ka cal BP). In the present paper, we examine most of these works, in order to unravel environmental changes of the past, mainly in terms of temperature, atmospheric pattern, precipitation, vegetation and faunal associations. The climate of the last glacial maximum was characterised by very low temperature and by repeated northerlies penetration, even during summer. Low precipitation values led to a steppe- or semisteppe-like vegetation pattern, dominated by herbs and shrubs. Episodes of climatic anomaly, characterised by lower temperature and strengthened wind activity, could have occurred during the Holocene, as testified by micropaleontological and geochemical investigations carried out on the southern Tyrrhenian Sea and in the northern Sicily Channel. In the terrestrial record, there is evidence of drought at 8.2 ka cal BP, from the isotopic composition of a stalagmite recovered near Palermo, and of prolonged drought intervals during the Little Ice Age in the Erice village (Trapani). The vegetation pattern shows the development of Mediterranean Maquis in coastal sites and deciduous forests in sub-montane and montane regions, approximately from the Holocene base. The human impact is the main factor that forced the present vegetation pattern, as a consequence of intensive land-use, which started about 2.7 ka cal BP, when Greek colonies were first established. Human activity is however superimposed on a natural trend towards aridity, with climatic forces still not fully understood.