Flandrian pollen deposition rates and tree-line history in northern Fennoscandia

Previous absolute polien diagrams from northern Fennoscandia yielded evidence for a retreat of the pine limit from an earlier extended position to a position near the modern one between about 5000 and 3000 B.P. New absolute pollen data from the sediment core of Domsvatnet, a small tundra lake near the eastern coast of Varanger Peninsula, are used to demonstrate a parallel retreat in the birch limit. Areas outside the modern birch limit were colonized by early Flandrian pioneer birch woods between 9500 and 9000 B.P. and remained as birch woodland through middle Flandrian times until a retreat started around 5000 B.P. leading to the present tundra situation.
The Domsvatnet core shows anomalous high pollen deposition rates combined with relatively rapid matrix sedimentation, suggesting that pollen from outside the basin has been washed in with allochthonous material and concentrated in the sediment.