新疆科克苏湿地自然保护区维管束植物区系

Study on the Floras of Vascular Plants in the Koksu Wetland Nature Reserve in Xinjiang

科克苏湿地自然保护区共有维管束植物65科259属551种,与西北其它荒漠地区相比,植物种类非常丰富。该区维管束植物科的组成以寡种科和区域性单种科为主,占总科数的66.2%,菊科、禾本科等较大科仅占总科数的15.4%,但所含物种数达到63%,在本区植物种的组成中占据重要地位;属的组成以小型属和区域性单种属占优,占植物总属数的94.6%。植物生活型以地下芽植物占绝对优势,达到40.1%,其次为一年生植物,为35.8%,这种组成比例与科克苏湿地的环境条件有着密切的关系。所有种子植物分属于11个分布区类型,以北温带、地中海与西亚、中亚和旧世界温带成分占明显优势,反映出该区植物分布的北温带性质,同时与地中海、西亚和中亚植物区系关系极为密切。

Located in the piedmont desert plain of the Altay Mountains, the Koksu Wetland Nature Reserve （47°38＇-47°43＇N, 87°28＇-87°30＇E, 476-496 m a. s. 1., 3.1 × 10^4 hm^2 in area） is an important desert wetland in northwest China, where the annual and the extremely maximum and minimum temperatures are 4.0 ℃, 39.5 ℃ and - 46.7 ℃ respectively, the annual accumulated temperature -10 ℃is 2 794.7 ℃, and the annual sunshine duration varies in a range of 2 825-2 960 hours; the annual precipitation and evaporation are 112.6 mm and about 2 000 mm respectively; in average, the frost-free period is from September 29 to May3; the soils including brown soil, meadow soil, aeolian sand soil, damp soil and bog soil change with the moisture and vegetation conditions. According to our preliminary statistics, there are 551 vascular plant species in 259 genera and 65 families in the Koksu Wetland Nature Reserve, and the plant species are much more abundant compared with that in other desert regions in northwest China. The composition of vascular plants in the Koksu Wetland Nature Reserve is dominated by depauperate families and endemic families, and their proportion is as high as 66.2% of the total, whereas the proportion of the large families containing more than 15 species in each family, such as Asteraeeae and Gramineae, accounts only for 15.4 % of the total, but the proportion of their species occupies 63 % of the total. The genus composition of vascular plants in the nature reserve is dominated by small genera and endemic genera, their proportion accounts for 94.6% of the total. The dominant life forms of vascular plants are mainly geophytes and therophytes, their proportions are 40.1% and 35.8 % respectively, and such composition is closely related to the environmental conditions in the nature reserve. The seed plants belong to 11 types of distribution areas and are dominated by the north temperate, Mediterranean, West Asian, Central Asian and Old World temperate elements.