Dati sulla vegetazione del periodo glaciale: antracologia dei siti paleolitici del nord Italia

Abstract

About three thousands hearth charcoals from northern Italy palaeolithic deposits were analysed. The anatomy of all charcoals was examined both in cross and longitudinal section with a metallurgical microscope. Scanning electron microscopy was used to photograph the key characteristics of the species. All the charcoals belong to the microthermic and heliophilus species. Many charcoals belong to trees which now grow near the alpine timberline. A great amount of coniferous charcoals belonging to: Larix decidua (Larch), Pinus cembra (Swiss stone pine, cembran pine) and Pinus sylvestris/mugo resulted from anthracological analyses. The wood that has been identified as Pinus sylvestris/mugo could have been both Pinus sylvestris (Scotch pine) wood - a single species - and a species of the Pinus mugo group (Swiss mountain pine). Among the identified charcoals only a few fragments belong to broadleaf taxa, Betuia, Salix, Rhamnus, Hippophae, Prunus and Pomoideae have been recognised. Many charcoals belong to Larix (probably Larix decidua). These trees produce only a few pollens which, moreover, easily decay. The larch is often absent in pollen diagrams but its abundance in fireplaces shows its large distribution at low altitudes during the Palaeolithic. The discovery of cembran pine charcoal in the upper Palaeolithic levels of Riparo Tagliente, confirms the pres-ence of this species at low altitudes during the Late-Glacial. In fact, although Pinus cembra pollens were found in many Late Glacial deposits, the presence of this species at low altitudes has never been seriously considered. Palaeobotanical data from the anthracol-ogical analyses carried out on the studied Palaeolithic sites of northern Italy indicate the presence of species which now grow near the alpine timberline. Thus, their presence at lower altitudes during the Late Glacial can be hypothesised. This is not in agreement with the interpretations of pollen diagrams assuming an early appearance of broadleaf forests at the foot of the Prealps. The presence of open forests with bare wide areas in the Late Glacial landscape may explain the deposition of loess on the Prealpine fringe.