广州流溪河常绿阔叶林的植物区系地理分析

常绿阔叶林是亚热带地带性植被类型。在广州流溪河上游流域，分布有少量的保存较好的常绿阔叶林，主要见于海拔200m以下的地区。由于分布面积狭小，因此其植物区系并不丰富。种子植物科、属的地理成分表明，该植被型的区系具有显的热带、亚热带性质，同时具有一定的温带成分，东亚和北美间断分布、泛热带分布和旧世界热带分布对该森林的区系性质影响很大。常绿阔叶林植被及其区系都是在中生代末起源于华夏古陆，其中少量的落叶成分也是干旱促成、华夏起源的。

An Analysis on Flora of the Evergreen Broadleaf Forest in Liuxihe River, Guangzhou

The evergreen broadleaved forest was one of the typical vegetations in subtropical area.In the upper reaches of Liuxihe river watershed, Guangzhou, this kind of forest was mainly found in areas below 200 m above sea level.So, its flora was not so rich relatively.According to the areal-types of families and genus of the carpophytes, the tropical-subtropical components were the most abundant, with a few temperate components.Together with its flora, the flora of evergreen broadleaf forest was originated on the Cathaysian ancient land during the early Mesozic.And, the deciduous components in this kind of vegetation came neither from the Pan-Arctic nor from the tropical, because the defoliation was not induced by the low temperature but the drought climate-the Cretaceous drought climate.