Climate and vegetation dynamics of the Northern Apennines (Italy) during the Late Pleistocene and Holocene

This study reconstructs the regional vegetation and climate dynamics between the upper Late Pleistocene and Holocene around Pian del Lago, a coastal mountain marshland located at 831 m asl in western Liguria (NW-Italy), based on the pollen analysis of a 13 m-long sediment core. The record provided a unique opportunity to study a poorly documented period in northern Italy and across many parts of southwestern Europe. We propose an event stratigraphy based upon the identification of seven interstadials (NAI-7 to NAI-1) spanning the upper Late Pleistocene. The correlation with other terrestrial records in Italy, and with Mediterranean marine sequences and the Greenland ice cores, permitted a coherent reconstruction of main environmental changes from >∼43,000 cal. BP. Significantly, the pollen record indicates the persistence of a mesophilous mountain vegetation cover, mainly composed of Quercus (deciduous and evergreen), Abies, Fagus and Alnus over the whole time period recorded. At the Last Glacial Maximum (LGM) and during the Late Würm Lateglacial, despite the presence of steppic vegetation composed of Artemisia, woodlands dominated by Pinus, with Abies, Picea, Fagus, Alnus and Betula are present. This forest composition provides an important insight into the history of Picea in southern Europe and Late Pleistocene refugia for mesophilous species. During the Early Holocene, Pinus is first replaced by Abies and then by deciduous Quercus and mixed temperate species as the dominant forest component. Both arboreal and herbaceous anthropogenic pollen indicators only make their appearance during the Late Holocene, attesting to the increasing importance of human activities