尼泊尔地区种子植物的区系地理成分及其生物地理意义

Floristic Geographical Elements of Seed Plants in Nepal and Its Biological Significance

利用尼泊尔地区大尺度的植物志资料,探讨该地区种子植物区系组成及板块归属。结果表明,尼泊尔地区拥有种子植物4 870种,分属于221科,1 403属。在属水平上,所占比重最大的区系分布类型是泛热带分布成分(T2)(17.18%),其次为北温带分布成分(T8)(14.75%)。在科水平上,主要以热带区系成分为主,其所占比重达到68.77%,而温带区系成分则仅为23.97%。无论在科水平还是在属水平上,该地区的种子植物区系均以热带区系成分为主。但从科到属的水平,热带区系成分所占比重从68.77%减少到51.60%。这可能与印度板块和欧亚板块相撞,导致地势抬升和环境热量降低有关。

On the basis of plant information at large scale in Nepal, this paper discussed the floristic geographical elements of seed plants and plate belonging. The results showed that 4 870 species of seed plants belonging to 1 403 genera and 221 families of seed plants were found in Nepal. At genus level, the largest proportion of the distribution type was the pantropical distribution elements（T2）which was about 17.18%, followed by north temperate elements（T8）, holding 14.75%. At the family level, tropical floristic element was the major part which was about 68.77%, while the temperate floristic element was only about 23.97%. At the family or genera level, the seed plant flora of the region was mainly tropical floristics element. However, from family level to genus level, the proportion of tropical elements decreased from 68.77% to 51.60%, which might be related to the uplift of Himalayan and the reduced ambient energy caused by the collision of the Indian Plate and the Eurasian Plate.