YOUNGER DRYAS POLLEN RECORDS FROM CENTRAL AND SOUTHERN YAKUTIA

Analysis of palynmorphic successions from central and southern Yakutia has resulted in enhanced understanding of the effects of the Younger Dryas event. During the Allerod, central Yakutia was marked by steppe conditions, with Artemisia, Chenopodiacene, Poaceae and other taxa, in addition to shrubs Betula nana and B. fracticosa. River floodplain ar eas supported larch-birch forests. The transition to the Younger Dryas environment, indicated by increases in steppe and tundra elements and decreases in arboreal taxa, was marked by decreases in mean summer te mperature by +/-3 degrees C, and drier conditions. Re-colonization of central Yakutia by larch-birch woodlands and ''yemik'' steppe assembla ges dominated by shrub birch marked the conclusion of the Younger Drya s. In southern Yakutia, the Allerod larch-alder-shrub birch vegetation assemblages were replaced by steppe assemblages dominated by bunchgra ss and forbs during the Younger Dryas. Subsequently, alder re-colonize d southern Yakutia, ca. 10,200-10,300 BP. (C) 1997 INQUA/Elsevier Scie nce Ltd.