哀牢山作为滇东高原与横断山系南段滇西南山地的分界线,其高大山脉造就了山体两侧气候、植被差异显著。本研究以沉积物孢粉为媒介,对山脉主峰两侧的植物物种区系成分进行对比分析。结果显示,哀牢山西坡样地受印度夏季风影响程度高于东坡样地,沉积物孢粉中热带成分大于东坡,分别为6.8%和4.7%;哀牢山东坡样地则受北来东亚冬季风影响显著,造成东坡样地孢粉中北温带成分远大于西坡样地,分别为26.4%和13.4%。哀牢山成为印度夏季风与东亚冬季风的重要分界之一。

As the natural boundary between the eastern Yunnan plateau and the southwestern Yunnan in Hengduan Mountains, the large-scale prominent terrain leads to obvious regional difference of climate and vegetation on both sides of Ailao Mountain. In this article, a comparative analysis is made on plant species floristic elements of sediment spore-pollen in two sample plots beside the main peak respectively. The results show that there is a remarkable difference on sediment spore-pollens between these two sample spots while there is no on the topsoil spore-pollens. The tropical genera elements of sediment spore-pollens is higher in the western sample plot (6.8%) than one in eastern part (4.7%) because the western plot is controlled by India summer monsoon at all times. And the north temperate elements of sediment spore-pollens is lower in the western sample plot (13.4%) than one in eastern part (26.4%) because the eastern plot is influenced evidently sometimes by East Asia winter monsoon. In a word, Ailao Mountain is one of important boundaries between India summer monsoon and East Asia winter monsoon.