太白山高山带2000多年以来气候变化与林线的响应

CLIMATIC CHANGES AND TIMBERLINE RESPONSES OVER THE PAST 2000 YEARS ON THE ALPINE ZONE OF MT. TAIBAI

本文通过太白山东佛爷池高山湖泊沉积物粒度、总有机碳 (TOC)、磁化率、孢粉和植物残体分析结果 ,结合现代高山林线的植被格局分析 ,探讨了太白山 2 30 0年来的气候变化过程以及高山林线对气候变化的响应机制 ,结果表明 :太白山 2 0 0 0多年以来的气候变化过程划分为以下几个时期 :2 2 5 0～ 1 80 0aB .P .,1 370～ 65 0aB .P .以及 2 0 0aB .P .以后的暖湿期 ;180 0～ 1 5 30aB .P .的冷湿期 ;1 5 30～ 1 370aB .P .的暖干期以及 65 0～ 2 0 0aB .P .的冷干期。温度变化过程与历史文献资料得出的平原地区的变化过程基本一致。

In this paper, climatic changes in the past 2 300 years and mechanism of alpine timberline responses are highlighted based on proxy data, including grain sizes composition, total organic carbon (TOC), magnetic susceptibility, pollen percentages and plant remnants of a sediment sequence from an ancient glacial lake, Dongfoyechi Pond, on the alpine zone of Mt. Taibai. The following stages of climatic change can be distinguished: warm and humid during 2 250～1 800 aB.P., 1 370～650aB.P. and after 200aB.P., cold and humid from during 1 800～1 530 aB.P., warm and dry during 1 530～1 370 aB.P., and cold and dry during 650～200 aB.P., The changes of thermal conditions are in consistent with those in plain area of eastern China,as implied from historical literatures.