喀喇昆仑山-昆仑山地区植物的生活型组成

THE CHARACTERISTICS OF PLANT LIFE FORM SPECTRA IN THE KARAKORUMKUNLUN MOUNTAINS

喀喇昆仑山－昆仑山地区植物生活型组成以地面芽植物为主，约占４５．１％。其次是隐芽植物（包括地下芽植物、水生植物和沼生植物），约占１９．６％。一年生植物、地上芽植物、高位芽植物分别占１５．８％、１０．５％、９．１％。然而，不同地段的植物生活型谱存在着明显的差异。昆仑北翼山地的３个地段（Ⅰ２、Ⅰ３和Ⅰ４）俯瞰着极端干旱的塔里木盆地，又有海拔３０００ｍ以下的山地荒漠带和山地荒漠草原带，其生活型谱比较相似，表现在一年生植物所占比例均在１５％以上，高于其余５个地段的约１０％；这３个地段地面芽植物的比例约为４０％，低于其余５个地段的约５２％。植物生活型谱随海拔高度的变化规律是，高位芽植物、一年生植物和隐芽植物在生活型谱中所占比例随海拔升高而下降，地面芽植物和地上芽植物所占比例随海拔升高而增加。这个结果说明一年生植物比较适应荒漠气候条件下降水量少、年变率大的特点，而不适应高寒地区低温、生长季短的气候特点。与此相反，地面芽植物和垫状、匍匐状地上芽植物比较适应寒冷地区气温低、生长季短的气候特点。

The 45 percent of the taxa in the KarakorumKunlun Mountains were Hemicryptophytes, and therefore they were the dominating components in the plant life form spectrum in the area. Cryptophytes, Therophytes, Chamaephytes and Phaenerophytes accounted for 196%,158%,105% and 91% of the taxa,respectively. The spectra differed among the eight sections of the region, especially between the southern and the northern flanks of the Kunluns. As the altitude ascends, the proportions of Therophytes and Cryptophytes descend while the proportions of Hemicryptophytes and Chamaephytes increased. The results suggest that Therophyte had been evolved to tolerate the desert climate characterized by small rainfall and great variation in annual precipitation. Hemicryptophytes as well as cushion and prostrate plants adapted well to the alpine climate characterized by low temperature and short growing season. 