Late Quaternary vegetation history at Lagaccione near Lago di Bolsena (central Italy)

The palynological study of the lacustrine sediments from Lagaccione, a maar -lake near Lago di Bolsena in central Italy, has provided a palaeoenvironme ntal record for the last 100,000 years. The chronology of the sequence is b ased on sixteen radiocarbon dates and a tephra layer at the base of the St Germain II s.l. The pollen record, starting during the St Germain I forest phase and ending about 3000 years ago, shows that remarkable changes occurr ed in the floristic composition, in the structure of the vegetation and in the plant biomass, including also long-lasting periods of open woodlands, o ften with an appreciable floristic diversity, during the last pleniglacial. Three new vegetational oscillations (Etruria I, Etruria II and Etruria III ), characterized by a well-defined vegetation composition and dynamics, hav e been recognized after the St Germain I forest phase and before the middle pleniglacial interstadials. New evidence has been obtained for a significa nt diffusion of deciduous trees in the Italian peninsula during the late-gl acial. (C) 1999 Elsevier Science B.V. All rights reserved.