滇西新近纪植物气孔、碳同位素组成与古环境分析

Stomata, Carbon Isotopic Composition of the Plants from the Neogene in West Yunnan and Paleoenvironmental Analysis

对滇西腾冲新近纪两种被子植物叶片及其现存对应种的气孔参数和碳同位素组成的综合分析表明:当时的大气CO2浓度略高于现在水平;化石种的碳同位素分馏值高于现存对应种,但水分利用效率低于现存对应种;这证明当时的气候条件比当前更为温暖湿润。受新生代全球气候变冷和喜马拉雅运动的影响,该盆地一方面受印度洋季风的影响增强,干湿季节交替明显;另一方面受地形地貌影响,沿袭了温暖湿润的气候条件。

The comparison of stomatal parameters in leaf cuticles between two fossil angiosperms from the Pliocene in West Yunnan and their nearest living equivalent species indicates a little higher atmospheric CO2 level at that time than the present,while carbon isotopic composition of fossil cuticles demonstrates much higher carbon isotopic discrim-ination and slight lower water use efficiency, showing a warmer and wetter climate than today. On the influence of global change of Cenozoic climate and uplift of Himalayas, the area began to present a distinct seasonal climate on the basis of previous warmth and humidity in Pliocene.