EARLY TO MIDDLE PLEISTOCENE CHANGES OF THE ITALIAN FLORA AND VEGETATION IN THE LIGHT OF A CHRONOSTRATIGRAPHIC FRAMEWORK

Abstract

Palynological data from selected Pleistocene Italian sites are presented. The chronostratigraphic framework of floral and vegetational
events illustrates the development of cooler climates during the Early and Middle Pleistocene. Floral and vegetational response to glacial/interglacial cycles, as well as major floristic and vegetal replacements (e.g. Taxodiaceae, Cathaya, Tsuga) are analysed with special attention to latitudinal and altitudinal gradients and to the different physiography of Italy. The pollen flora shows marked changes both at the beginning of the Pleistocene as well as at the time of the Mid-Pleistocene climate transition, when a major decrease in temperature, during steppe and forest phases, occurred. Alternations of Artemisia steppe and temperate to warm-temperate deciduous forest mark the overall glacial-interglacial vegetation changes in Italy. Glacials, however, do not correspond to dramatic drops of moisture in Northern Italy. Cycles here are characterized by the alternating spread of deciduous broad-leaved forests and altitudinal coniferous forests (mainly Picea) with no significant occurrence of steppe vegetation. Several sites from northern, central and southern Italy are described; reference sections permit correlations also of sites with poor time-diagnostic content. The quality of data is crucial in the application of advanced methodologies in palynology for reliable climate quantifications as well as for the elaboration of vegetation paleomaps.