Pollen-recorded bioclimatic variations of the last ∼22,600 years retrieved from Achit Nuur core in the western Mongolian Plateau

This research focuses on the reconstructions of vegetation variations and the associated climate changes over the past similar to 22,600 years based on pollen data of 91 samples obtained from Achit Nuur in the western part of the Mongolian Plateau. The vegetation in the Achit Nuur area was forests in higher elevations and steppes in lower elevations from similar to 22,600 to similar to 13,200 cal BP. The subsequent period from similar to 13200 to similar to 6400 cal BP was characterized by steppes in higher elevations and deserts in lower elevations, followed by taiga expansion in high elevations in the following period from similar to 6400 to similar to 1600 cal BP. The last similar to 1600 years were characterized by high herb percentages. Pollen-based reconstruction of the temperature showed that the Achit area experienced cold conditions between similar to 22,600 and similar to 13,200 cal BP and mild conditions from similar to 13,200-similar to 6400 cal BP with the past similar to 5000 years being relatively warm. The reconstructed precipitation suggests two wet periods: (1) from similar to 22,600 to similar to 13,200 cal BP and (2) from similar to 6400 to similar to 1600 cal BP. The two intervening dry periods are (1) from similar to 13,200-similar to 6400 cal BP and (2) from similar to 1600 to 0 cal BP. (C) 2013 Elsevier Ltd and INQUA. All rights reserved.