Abstract:
The pollen stratigraphy of an ombrotrophic patterned ridge-hollow raised bog in the Salym-Yugan Mire Area in boreal West Siberia (60°109N, 72°509E) covers the entire Holocene period. Pollen data from three parallel peat cores suggest that, contrary to previous assumptions, Betula forests did not spread into tundra until the Boreal period (9000–10000 cal. BP). After 9000 cal. BP, Pinus sylvestris and Picea abies forests displaced Betula forests in the area and dominated until 4100–4300 cal. BP, when Picea decreased considerably due to a climatic change and Pinus sylvestris became the most abundant tree species. Average pollen influx estimates during the wooded period, from about 9000 cal. BP onwards, were 5600–6350 grains cm–2 yr–1, similar to pollen-trap estimates from boreal coniferous forests.
