HOLOCENE VEGETATION AND CLIMATE IN THE AREA NORTH TO THE BLACK SEA

Climate and environmental situation in the steppe and forest-steppe belt north of the Black Sea was far to be stable in Holocene. Global warming in early Holocene allowed an expansion of broad-leaved trees in East Europe. 12,000-10500 BP in the forest-steppe belt pine and birch dominated in forests, but there was a significant admixture of broad-leaved trees. Ulmus, Quercus, Tilia, Carpinus grew in south-west of forest-steppe in East Europe at 10500-8800 BP. At 9000 BP broad-leaved trees reached the forest-steppe belt in Middle Russian Hills. At 10500-4800 BP pine forests with birch grew on sandy terraces of Dniepr, Severski Donets and Don. In the Dniepr valley Pinus, Quercus, Tilia, Carpinus betulus, Fraxinus reached the modern shore-line of Black sea at 8800-8300 BP. Period 8300-6800 BP was characterised by warm climate. The area of valley forests in the steppe belt has reduced. Climate became more benign between 6800 and 4800 BP. That time evidenced a maximum spread of broad-leaved forests in river valleys and in the forest-steppe belt. Human influence of the vegetation cover increased with the expansion of farming. Human influence on the vegetation became evident according to pollen investigation of archaeological sites. There were numerous sharp climate oscillations between 5200 and 1600 BP. Climate became more dry and continental after 5200 BP. The peat accumulation rate in mires dropped down for two-four times. Pine forests area decreased. In north Kalmukia forested area in Ergeni hills was in decline since 5400-5200 BP. The most continental phase of climate is dated between 4800 and 4000 BP. Forest area was reduced in Dniepr, Don and Volga basins. New phase of moist climate is dated 3700-2900 BP. At that time broad-leaved forests expanded in river valleys and in the forest-steppe belt. After 2600 BP the vegetation cover became similar to the modern. After 2100 BP pine was extinct in the lower part of Dniepr valley. Degradation of forests was caused by combined effect of climate deterioration and human impact. During two last millennia pollen indicators of human activities are recorded in pollen diagrams in south of Moldova, in forest-steppe belt in Ukraine. East from the Dniepr valley human impact on the vegetation cover became evident on pollen data only during last millennium.