云南宁蒗泸沽湖地区的古环境重建

THE RECORD OF PALEO-CLIMATIC ENVIRONMENT IN LUGU LAKE AREA OF NINGLANG COUNTY, YUNNAN

在以岩溶记录重建区域岩溶发育史的基础上 ,以洞穴沉 (堆 )积物 (特别是高分辨率 )的洞穴沉积物提取石笋的气候、环境记录 ,建立了泸沽湖地区全新世以来气候环境演化过程 :6 5 6 8a前凉湿间暖 ,偏冷 ,植 (草 )被较好。至 4184a间 ,凉温湿间凉干 ,是转暖过渡期 ,主跃变在 4396～ 4749a间 ,植被好。 4184a至今 ,温暖湿润间冷 (凉 )干 ,转冷 ,植 (草 )被良好 ,局部转草被 ,近期趋向荒漠化 ,且局部已极严重。植被演化和干旱化趋势 ,源于自然因素 ,人类因素仅在局部范围或有限时段是主导因素。

On the basis of the karst development history in the regions where karst records are reconstructed, the evolution process of climate and environment since the Holocene epoch in the Lugu lake area has been established by using the records of cave sediments, especially the climatic and environmental records extracted with high resolution from stalagmites. Cool humid climate was intercalated with the short warm climate period in 6568a B.P., and vegetation covered well. And cool warm humid climate was intercalated with dry and cool climate between 6568a and 4148a B.P., which was an interim warm period. The key jump change period is between 4396a and 4749a B.P., vegetation covering well. The climate became cold from 4148a B.P. to the present, including a warm humid period intercalated with dry cool or cold period, vegetation covering very well. In the near future it exists a trend of desertification, some areas having been very serious. The evolution of vegetation cover and the trend of drought result from natural factors,but human factors are dominant only in some regions or during a limited period.