Abstract:
Judging from an ecophysiological viewpoint,the altitudes of plants generally would become lower with the increase of their latitudes.As to some characteristic elements in the Yunnan flora,however,the situation has been found to be an exception.The distribution of these elements is similar to the distribution of the Yunnan Ancient Planation Surface.That is,there is a positive correlation between the altitude and the latitude of the distribution.The difference between them is that the elevation of the Yunnan Ancient Planation Surface’s distribution trendline is larger than that of the floristic elements.The likely reasons are the biological characters of these species and the adaption delay of plants relative to the geological change.According to the principle of distribution area’s generating, the origin of characteristic elements should be earlier than the uplift of Yunnan Ancient Planation Surface.