滇川干热河谷种子植物区系成分研究

论及滇川干热河谷种子植物区系成分由科级到种级的研究结果。用于统计分析的植物共1707个种，分属于752个属，165个科．科级区系成分中，除广布科外，明显为主，其次为暖温带科和热带科，热带科有27个科，远比干暖河谷区系中的热带科多。属区系成分中，热带属占明显多数，有523个属，占75．03％，温带属158个，占22．67％，有个中国特有属。种级区系成分中，有中国特有种622个，占37．42％，热带种791个，占47．59％，温带种249个，占14．88％。干热河谷的植物区系标志种很丰富，有437种，分三个等级，其中一级为本河谷特有种，有45种，二级199种，三级193种。热带科、属、种偏多说明本河谷历史上以热带区系为主和近代区系源于热带。干热河谷的特有区系成分和区系的标志种均较好地反映本河谷区系成分组合特征、演化的近代趋势、区系的多样性及其独特性。

The floristic study on seed plants in the dry-hot valleys in Yunnan and Sichuan

This paper studies the floristic elements in seed plants from families to species in dry-hot valleys in Yunnan and Sichuan. There are 1707 species for statistics and analyses, which belong to 752 genera and 165 families.The results showed that most of the families are subtropical with the exception of world-wide species, and then less are warm-temperate and tropical. There are 27 tropical families, greatly more than those in dry-warm valley. At genus level, the number of tropical genus is significantly the most which are 532, account for 75.03 %, the warm-temperate genus 158, for 22.6 % and 16endemic genera of China are found in this study. In all species, there are 622 China endemic species, account for 37.42 %; 791 tropical species, for 47.59 % and 249 warm-temperate species, for 14.88 %. The 437 characteristic species of dry-hot valley flora are divided into 3 classes. Among them,the first class is valley endemic species, account to 45, while the second class are 199 and the third are 193, The numbers of tropical families, genera and species also show that the tropical floristic elements had been the majority in history and the recent floristic elements originated from tropical.Meanwhile, the endemic and characteristic elements of dry-hot valley flora are also showing the characteristic of the component, evolutonal tendency, floristic diversity and its unique in this area.