VEGETATION HISTORY AND CLIMATE OF THE LAST 15,000 YEARS AT LAGHI-DI-MONTICCHIO, SOUTHERN ITALY

In southern Italy, vegetation contemporary with the end of the last gl acial maximum, from 15,000 to 12,000 years ago, is shown by pollen-ana lysis to have been treeless and steppe-like in character. At 12,500 BP (years before present), Betula (birch) expanded into the steppe, quic kly followed by Quercus (oak), Fagus (beech), Tilia (lime) and other t ree genera of mesic forest. High percentages of Tilia point to a rich mesic forest that was contemporary with the 'Allerod' interstadial of northern Europe. A major decline in mesic trees with an accompanying r eturn of Betula and steppe genera dated to 10,500 years ago identifies a 'Younger Duyas' climatic reversal. Betula and steppe genera were re placed by forest of Quercus and other mesic trees, notably Ulmus (elm) , as the Holocene began. In the later Holocene, ca. 4000 years ago, Ab ies (fir), Carpinus betulus (hornbeam) and Taxus (yew) appeared. Abies and Taxus became extinct locally about 2500 years ago, either because of climatic change, or perhaps because of the effects of early agricu lture. The Full-glacial climate is thought to have been cold and summe r-dry with mainly winter precipitation. The Lateglacial 'Bolling-Aller od' Interstadial was summer-wet and warm. The response-surface based c limate reconstruction indicates an early Holocene climate with markedl y colder winter conditions than today, about -5 degrees C compared wit h 3.9 degrees C today as a mean temperature for the coldest month. The annual temperature sum is reconstructed as somewhat higher than today , 3500 degree days as compared with a calculated value of 2900 for tod ay. The later Holocene had a climate like today's. Rainfall, and varia tion in its seasonal distribution, has been a critical determinant of the vegetation cover. The fossil pollen record at Laghi Di Monticchio has been complemented by diatom and plant macrofossil studies which pr ovide evidence of former lake environments as well as data on the upla nd forest. Lake levels remained high during the Full- and Lateglacial with encroachment of shore vegetation during the Holocene. The sedimen ts also have an exceptionally rich record of tephra falls which are of importance in dating and core correlation. Twenty-one macroscopically visible tephras occur in sediments of the last 15,000 years. (C) 1996 Elsevier Science Ltd