新疆阿尔泰山大罗坝盆地全新世植被与环境

THE HOLOCENE VEGETATION AND ENVIRONMENT IN DALUOBA BASIN OF ALT AY MOUNTAINS, XINJIANG

阿尔泰山中部大罗坝盆地3.2m厚沉积中的孢粉化石可以划分出2个孢粉组合和8个亚组合。晚更新世晚期—早全新世属荒漠草原—草原植被,中晚全新世属森林草原植被。7000a.BP以来,盆地中针叶林一直发育较好。森林发育的最好阶段是中全新世早期,此后曾有两次衰落时期,但森林并未退出本区。从全新世阿尔泰山喀纳斯湖地区与大罗坝盆地的孢粉对比发现,森林的分布从西向东有减少趋势,温度逐渐降低,推测阿尔泰山东部的青河县气候比较干旱。

Two spore-pollen assemblages and eight spore-pollen sub-assemblages are divided within the 3. 2m deposit of Daluoba Basin,Altay Mountains.From late stage of Late Pleistocene to Early Holocene, this area was of desert steppe to steppe, and then it became coniferous forest steppe in the Middle and Late Holocene. Since 7 000 a BP,coniferous forest has been well developed. In Daluoba Basin,the coniferous forest was mostly developed in the early time of Middle Holocene. Afterward the coniferous forest failed two times, but it still grew in the area. Based on the comparison of spore-pollen in Kanas lake and Daluoba Basin the Holocene coniferous forest descreased gradually and the climate got drier and drier from the west to the east in Altay Mountains.