Analisi palinologiche e geofisiche per la ricostruzione delle trasformazioni ambientali nella regione lariana tra Tardiglaciale e Olocene: nuovi dati dal sondaggio di Piazza Verdi a Como.

The analyses of the present research were performed on lacustrine sediments sampled through a continuous drilling conducted in Como-Piazza Verdi (Lombardy, Southern Alps), about 200 m far from the shore of Lake Como. A multidisciplinary approach (mainly stratigraphy, palaeobotany, geophysics) was adopted to reconstruct the palaeoenvironmental evolution in Como basin. The oldest phase of the Lateglacial was characterized by the melting of the Abduan ice tongue covering the present-day Como town area. Later, the slopes facing the proglacial and post-glacial Lake Como were colonized by pioneer vegetation. During the Bölling-Allerød the temperatures rose and a continental forest spread. At the end of the Lateglacial the role of this phytocoenosys gradually became less relevant and some mesophilous species appeared. Thanks to the climate amelioration during the Holocene these species formed a mesophilous mixed forest. During Copper Age the human factor prevailed over the climate: 5100 cal yr BP the use of fire, adopted by men to deforest, caused the disappearance of silver fir, a species very sensitive to fire; the cool-wet oscillation in progress at that time would naturally encourage its development. The present research has innovative features from the methodological point of view and presents the first extensive pollen record for the Como subsurface. The results emphasize the need for further improving the knowledge about the palaeoenvironmental evolution in the Lake Como area.