Holocene Vegetation and Climate History of the Cheshskaya Bay Region, SE Barents Sea, Inferred from the First Pollen Archives

Abstract

First high-resolution micropaleontologic investigation was carried out for bottom sediments of the Cheshskaya Bay (SE Barents Sea) and marine beds exposed in abrasive terrace along the eastern coast of the Kanin Peninsula. Sediments from 2 gravity cores and a 7.5-m thick terrace section were analyzed for pollen and non-pollen palynomorphs (NPP), including spores, freshwater green algae and cysts of marine dinoflagellates. The age of the sediments was constrained by the reference to the regional sea-level history from the earliest Holocene to present, thus the pollen records reveal the environmental history for the last ca. 10.0 ka. Sparse treeless vegetation with dwarf Betula and halophytic inhabitants of seaside watts (cereals, wormwood and sedges) indicating arctic desert environment with colder and drier than present climate dominated the Cheshskaya Bay coast during the early Preboreal period. Gradual advance of shrubby-birch and piny forest-tundra with alder communities along river valleys resulted from significant climate amelioration which concurred with the Pholas inundation since the Boreal period. Postdated expansion of tree-birch inland the Kanin Peninsula and firry-birch light-forests along the Cheshskaya Bay coast marked the Holocene regional climate optimum. Re-establishment of the dwarf-birch and piny forest tundra signalized vegetation feedback to the cooling since the end of Atlantic period.