Late Holocene changes in the high-altitude vegetation of mountainous areas of north-central Greece and the role of grazing

Palynological studies have been carried out in the Lailias, Belles, Voras and Pieria (Flambouro) mountains which are located in north- central Greece. The four mountainous sites share some common geological and vegetation features. All sites have crystalline bedrocks and the high altitude forest vegetation is dominated by beech and/or pine forests though there are differences among these areas regarding the extent of these forest types, their location in relation to the coring sites etc. A distinct subalpine zone is present in all sites except Lailias and is dominated by Juniperus communis ssp. nana, ericaceous dwarf shrubs and extended grasslands. A comparative palynological study of the changes in the high-altitude vegetation of the four sites is attempted covering the Late Holocene. Pollen types related with human induced disturbance (e.g. forest clearings, animal husbandry) are compared up against pollen types of major forest vegetation units. Signs of local grazing pressure can be traced in various time periods in the diagrams of Beles, Lailias and Pieria. Though traceable in the Voras diagram, grazing pressure seems to have no major impact on the forest vegetation.