Holocene treeline history and climate change across northern Eurasia

Radiocarbon-dated macrofossils are used to document Holocene treeline histo ry across northern Russia (including Siberia), Boreal forest development in this region commenced by 10,000 yr B.P, Over most of Russia, forest advanc ed to or near the current arctic coastline between 9000 and 7000 yr B.P. an d retreated to its present position by between 4000 and 3000 yr B.P. Forest establishment and retreat was roughly synchronous across most of northern Russia, Treeline advance on the Kola Peninsula, however, appears to have oc curred later than in other regions. During the period of maximum forest ext ension, the mean July temperatures along the northern coastline of Russia m ay have been 2.5 degrees to 7.0 degrees C warmer than modern. The developme nt of forest and expansion of treeline likely reflects a number of complime ntary environmental conditions, including heightened summer insolation, the demise of Eurasian ice sheets, reduced sea-ice cover, greater continentali ty with eustatically lower sea level, and extreme Arctic penetration of war m North Atlantic waters. The late Holocene retreat of Eurasian treeline coi ncides with declining summer insolation, cooling arctic waters, and neoglac iation, (C) 2000 University of Washington.