The Holocene bottom sediments of the Tsaga-3 Lake (Kola Peninsula) are studied by
means of spore-pollen analysis, geochemical analysis and radiocarbon dating. The results of the
studies as well as biome reconstruction suggest the dominance of tundra in the preboreal period.
Birch forests propagated in the boreal time. Birch-pine taiga forests developed within the studied
territory in the Atlantic period. In the subboreal/subatlantic time, the vegetation of the region was
characterized by birch-pine and birch-spruce forests. The highest values of the lake's
bioproductivity are associated with the subboreal period.