松嫩平原晚更新世以来古植被演替的初步研究

根据松嫩平原不同地点六个剖面的孢粉分析资料及测年数据, 恢复该区晚更新世晚期以来的六种植被类型, 并且对晚更新世晚期在冰缘气候控制下的三种模式孢粉组合所代表向三种典型植被类型进行讨论。

PRELIMINARY RESEARCH OF VEGETATIONAL SUCCESSION ON THE SONG-NEN PLAIN SINCE LATE PLEISTOCENE

According to the characteristics of spore-pollen assemblages from six section of the Song-nen plain and C¹⁴ dating. Since late period of the latepleistocene, the vegetational succession divided into six stage. Stage Ⅰ. (60000-30000 yr.) The formation is characteristed by dark co-niferous forest-steppe, Which mainly consists of Pinus, Picea, Chenopodiaceae.Artemisia and accompany Botrychum, Lycopodium. That time climate was cold and humic. Stage Ⅱ. (30000-21000 yr.) The formation is dominated by theropeu-cedrymion-steppe or brich forest-steppe. In which, Pinus, Betula, Artemisia or Betula and Artemisia is dominated, At that time, the climate was mild andcold. Stage Ⅲ. (21000-11000 yr.) The formation is dominated by dry steppeor open steppe or weed. Which has Chenopodiaceae, Artemisia or Pinus and Chenopodiaceae. Vegetation rare. The climate was dry cold. Stage Ⅳ (11000-7500 yr.) The formation is dominated by theropeuced-rymion, rare forest-meadow or meadow-steppe. In which, Pinus and. Betula ispredominated. On the middle plain, increase of the decidous broad-leavedtree. The climate was mild and slight humid. Stage Ⅴ. (7500-2500 yr.) The formation is dominated by decidousbroad-leaved forest, forest-meadow or forest-steppe.Which mainly consists of Pinus, broad-leaf tree. Cyperaceae and Artemisia. The species has Juglans, Tilia, Carpinus and a lot of Cyperaceac. The swamp is developed. Peat isaccumulated. The climate was warm, moist. Late period the climate slightcold. Stage Ⅵ. (2500-Present) The formation is dominated by the conifrousforest. theropeucedrymion or meadow-steppe. The climate resemble recent. It is proved C¹⁴ dating and fossil of the vertebrate. Stage Ⅰ-Ⅲ belongto late period of the late Pleistocene. Stage Ⅳ belong to early Holocene.Stage Ⅳ belong to middle Holocene, Stage Ⅵ belong to Late Holocene. During late period of the late pleistocene, due to it is influenced bythel ow temeperate weather from terrestric glacier of the Sibirica. All the North-East plain by control of the preglacier climate, it is cold and grown a lot of xerophytes, formed an especial plant association. its contain treepollens:Pinus, Picea, Betula. Herb pollen:Chenopodiaceae, Compositae, Gramineae and Spores of fern:Botrychum, Selaginella, Locopodium. That late period of the late pleistocene, the vegetational type arethree model vegetational landscape of the preglacier and sporepollen ass-emblages is model assemblage under preglacier climate also. Its was one ofthe symbol layer of late pleistocene.