Holocene vegetation succession and responses to climate change in the northern sector of Northeast China

Sediment pollen samples from the Huola Basin in the northern sector of northeast China, and surface pollen samples from its environs, were analyzed to reconstruct accurately the historical response of vegetation to climate change since 9100 cal yr BP. Pollen analysis of the Huola Section indicates that vegetation experienced a transformation from early-mid Holocene warm-cold mixed vegetation to late Holocene cold-temperate vegetation. From 9100 to 6000 cal yr BP, the study area was warmer and moister than at present, developing Corylus, Carpinus, Pinus, Picea, Betula and Larix-dominated forests. Two cooling events at 6000-5000 and 3500-2500 cal yr BP led to a decrease in Corylus, Carpinus and other warmth-loving vegetation, whereas cold temperate forests composed of Larix and Betula expanded. After 2500 cal yr BP, Larix and Betula dominated cold-temperate vegetated landscapes. The Holocene warm period in NE China (9100-6000 cal yr BP) suggests that such warming could have resulted in a strengthening of the influence from East Asian Summer Monsoon on northernmost NE China and would have benefited the development of warm-temperate forest vegetation and an improved plant load, which also provides the similarity model for the possible global warming in the future.