Holocene vegetation history at Vatsari, Inari Lapland, northeastern Finland, with special reference to Betula

A Holocene sediment series from a lake in the northern birch forest region of eastern Finnish Lapland was studied pollen-analytically. In addition to conventional pollen analysis, birch pollen measurements were carried out. B etula pollen diameters were measured systematically. The resulting size-fre quency distributions were analysed statistically to infer their species com position and to reconstruct the local history of birch. The results indicat e pine arrival about 7500 C-14 years BP. Even during its optimum period of 7000-6000 BP, pine cover seems to have been thin and discontinuous. Pine an d birch started to retreat soon after the pine optimum. In the interpretati on of the birch pollen-size frequency distributions, no continuous record o f Betula tortuosa was found. B. pendula seems to have bad a more northerly distribution in the past than it has today.