HR: 13:55h
AN: PP33D-02    [Abstracts]
TI: Lateglacial-Holocene Environment History, Kazakhstan
AU: * Kremenetski, K
EM: costya@geog.ucla.edu
AF: UCLA, Department of Geography, 1255Bunche Hall 405 Hilgard Ave, Los Angeles, CA 90095,
AU: Velichko, A
EM: paleo@online.ru
AF: Institute of Geography, Staromonetny Lane 29, Moscow, 109017, Russian Federation
AB: Kazakhstan is located in central Asia between Caspian Sea and Tiang-Shang Mountains. Few well dated holocene sequences from the forest-steppe and steppe belt of Kazakhstan provided information about the vegetation and climate history. Mokhovoe mire was studied in the watershed of Tobol and Ubagan rivers. That's the most thick peat mire in northern Kazakhstan. Sedimentation in the Mokhovoe sequence started ca. 7800 BP. At that time regional vegetation was represented by steppes and birch-poplar forests. Pine penetrated in the Tobol region likely between 6500 and 6000 BP. Pine grew on sand terraces of Tobol River together with birch. At 3000-2900 BP Tilia, Quercus, Ulmus grew in north-west Kazakhstan.The general structure of vegetation was the same as at 6500-6000 BP. At 1900-1500 BP climate became less continental and pine forests with pure pine canopy expanded on sandy terraces of Tobol and Ubagan rivers. Soon after 1500 BP broad-leaved trees were extinct from the regional forests. Pashennoe lake is located in Karkaralinsk mountains in the most elevated part in the south-east part of the Kazakhstan lowhills. Dry grass-wormwood and wormwood steppes were spread in the region at 10500-8200 BP. Picea obovata and Hippophäe rhamnoides occurred in protected parts in intermountain valleys of Karkaralinsk mountains. Salix and Betula also occurred in valleys. Between 8000 and 6000 BP forest vegetation in Karkaralinsk mountains was represented by birch forests. Pine penetrated to Karkaralinsk mountains between 6000 and 5500 BP, but it didn't formed large forests. At the same time the maximal spread of Alnus glutinosa was reconstructed. The general structure of regional vegetation was stable up to. At 1500 BP pure pine forests expanded over Karkaralinsk mountains and around Pashennoe lake. Few lakes were investigated in Borovoe mountains in south of Kokchetav region of Kazakhstan. In early Holocene birch forests dominated in regional vegetation. Pine expanded in Borovoe at ca 7000 BP. Pine forests have been dominating in regional vegetation since 5300-5200 BP. The section of lake-bog sediment of Ozerki mire in the Irtysh river valley represents the history of vegetation and climate in southern margin of the West Siberian Lowland since 14,000 BP. Dry cold steppes grew in the Irtysh valley at 14,000 BP. Picea obovata and Hippophäe rhamnoides occurred in the Irtysh valley together with Betula and Salix. Climate became slightly warmer between 12,000 and 9500 BP. After 9500 BP Picea was extinct in the Irtysh valley and regional vegetation was represented by dry steppes and birch forests with willows near streams and lakes. At 6300-6200 BP pine penetrated to the Irtysh valley around Ozerki. Pure pine forests have been dominating in the Ozerki region since 5500 BP and the general structure of regional vegetation is very similar to the modern one.
DE: 0473 Paleoclimatology and paleoceanography (3344, 4900)
DE: 3344 Paleoclimatology (0473, 4900)
DE: 4900 PALEOCEANOGRAPHY (0473, 3344)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting