关键词: 植物多样性, 区系组成, 科水平, 属水平, 墨脱地区

Abstract:

The analysis of flora diversity and floristic composition are of great significance to understand floristic origin and
distribution. On the basis of plant distribution data at large scale, this paper examined the plant diversity and floristic composition in
Motuo region in Southeast Tibet at the family and genus level, respectively. The results showed that the studied area harbored a total of
1 049 species of seed plants, subordinated in 512 genera, 128 families. The studied area may be one of the plant diversity centers in the
Tibet region, with only 2.6% of the total land area. Flora at the family level showed strong tropical traits, while we observed significant
floristic transition at genus level. This vast contrast of proportions of temperate and tropical elements may be on account of the different
geological histories reflected by floras at families and genus level and the uplift of Qinghai-Tibet Plateau. It's also found that compared
with Southwest Yunnan regions, Southeast Yunnan regions and South Yunnan, flora of Gongshan regions in Northwest Yunnan showed
much stronger associations with the floristic composition and origin in the studied area.

Key words: plant diversity, floristic composition, family level, genus level, Motuo region