中国喀喇昆仑山十字花科多样性与区系分析

Analysis on Species Diversity and Flora of Cruciferae in the Karakorum Mountains of China

中国喀喇昆仑山十字花科植物共有32属66种1变种,其中单种属20属20种,寡种属9属22种,多种属3属24种,单种属与寡种属共占90.63%,在属级水平上占优势,三者在种级水平上差异不大。生活型以地面芽植物为主,高达69.69%,其次为一年生植物,占28.79%;其区系地理成分可分为8个分布区类型和6个变型,北温带分布及其变型占首位,达33.33%,区系温带性质比较明显;与邻近地区相比,该区与中国帕米尔高原十字花科植物属、种相比,相似性系数最高,分别为71.64%和52.62%,与东喜马拉雅、阿富汗的属相比相似性系数次之,分别为45.82%和26.87%,属间联系较密切,但种的相似性系数较低。

There are 66 species and 1 variety in 32 genera of Cruciferae in the Karakorum Mountains of China,in which there are 20 species in 20 monotypic genera,22 species in 9 oligotypic genera and 24 species in 3 multiplicate genera.At the level of genera,the proportion of monotypic genera and oligotypic genera is dominant（90.63%）.At the level of species,the difference among them is not significant.Hemicryptophytes of Cruciferae are dominant（69.69%） in the study area,and therefore they are the dominating components in the plant life form spectrum in this area,then followed by annual plants,and their proportion is 28.79%.The flora contains 8 areal types and 6 subtypes,the proportion of north temperate elements is as high as 33.33%,and the main distribution type is temperate nature in this area.Compared with the peripheral regions,the similarity coefficients of the Pamirs and the Karakorum Mountains of China are the highest at the level of genera and species,accounting for 71.64% and 52.62% respectively,and then those of the east Himalaya and Afghanistan,accounting for 45.82% and 26.87% respectively at the level of genera,but their similarity coefficients are low at the level of species.