Vegetation development in the Lake MiłKowskie area, north-eastern Poland, from the Plenivistulian to the late Holocene.

Pollen and fossil green algae studies of bottom sediments from Lake Milkowskie provide new data about the post-glacial history of terrestrial and lacustrine vegetation in the Great Mazurian Lake Dis- trict region. The studied basin is a small gully lake fi lled up with sediments almost 25 m thick, which were partly annually laminated. This paper describes the events and stages of plant cover development from the Plenivistulian ca. 16 600 cal. BP, when the sediment deposition process began, until the younger Holocene ca. 3800 cal. BP. Special attention is paid to Late Glacial palynostratigraphy which is poorly known so far. Detailed radiocarbon chronology has made it possible to determine the age of particular phenomena, which is especially important in the context of sedimentological gaps present in the Late Glacial section. The stud- ied profi le is the longest pollen record of post-glacial evolution of vegetation in north-east Poland. Pollen analysis, for example, revealed the local presence of Larix since the Plenivistulian; the early dominance of Hippophae rhamnoides ca. 14 400-14 200 cal. BP; the early immigration of tree birches (confi rmed by mac- rofossil remains) and the establishment of woodland at ca. 14 200-14 150 cal. BP; the rapid opening up of the landscape and intensive development of juniper at ca. 12 600-12 000 cal. BP and the late migration of spruce ca. 3900 cal. BP. Palaeoalgological studies showed a close correlation among climate, sediment type and fossil green algae taxonomic composition.