库姆塔格沙漠不同区域种子植物物种组成与区系特征研究

库姆塔格沙漠是我国西北荒漠地区较典型的沙漠之一,本文基于实地调查并结合遥感资料,对该地区植被的物种组成及种子植物区系特征进行了研究。结果表明:(1)库姆塔格沙漠地区共有种子植物29科91属143种;该地区植物物种贫乏、生活型简单,主要以灌木、一年生及多年生草本植物为主。(2)库姆塔格沙漠地区的植物组成受水分、高温以及土壤盐分等因子影响,形成了3个主要的种子植物分布区(阿奇克谷地、阿尔金山山前洪积扇戈壁、西湖湿地),且各区的物种组成差异显著。(3)从3个主要植物分布区的物种组成与生活型组成来看,阿尔金山山前洪积扇戈壁区域植物生活型比阿奇克谷地和西湖湿地丰富;因阿尔金山山前洪积扇戈壁环境复杂,在3个区域中其物种相对丰富,科、属、种的种类较多;阿奇克谷地和西湖湿地植物的属、种相似度较高;3个区域的植物属、种总体上相似度较低。(4)库姆塔格沙漠地区种子植物区系表征科主要为藜科(Chenopodiaceae)、菊科(Compositae)、麻黄科(Ephedraceae)等;3个主要植物分布区科的分布型均以世界分布为主,属的分布型以北温带分布和地中海区、西亚至中亚分布为主,具体表现为:阿奇克谷地和西湖湿地植物属的分布型以地中海区、西亚至中亚分布为主,阿尔金山山前洪积扇戈壁植物属的分布型以北温带分布为主。(5)库姆塔格沙漠地区种子植物以旱生种所占比例较高,物种类型具有明显的残遗性;由于环境条件特殊,形成了库姆塔格沙漠地区特有的植物类群和区系特征。本研究结果为库姆塔格沙漠地区植物组成及区系研究提供了基础资料。

Composition of Seed Plant Species and Flora Features in Different Areas of the Kumtag Desert of China

We studied the flora and composition of seed plant species in the Kumtag Desert, a typical region in northwest China, by field investigation and remote sensing. The results showed that: (1) There were 143 plant species belonging to 29 families and 91 genera. Among these species, annual and perennial plants were the main life forms. The species composition was deficient, and plant life-form was simple. (2) The Aqik Valley, piedmont alluvial-pluvial fan of the Arjin Mountain, and Xihu Wetland formed three distinct seed plant distribution areas in the Kumtag Desert, which were influenced by water, high temperature and soil salinity. The differences in species composition for the three regions were significant. (3) The life forms in the piedmont alluvial-pluvial fan of the Arjin Mountain were richer than those in the Aqik Valley or Xihu Wetland. Additionally, the piedmont alluvial-pluvial fan of the Arjin Mountain had the richest families, genera and species. Higher similarities in genus and species were observed between the Aqik Valley and Xihu Wetland. (4) Chenopodiaceae, Compositae and Ephedraceae were the dominant families in the Kumtag Desert. The main distribution pattern of the families in the three regions was Cosmopolitan. The main geographical elements of all genera in the Kumtag Desert were Mediterranea. W. Asia to C. Asia in the Aqik Valley and Xihu Wetland, and North Temperate in the piedmont alluvial-pluvial fan of the Arjin Mountain. (5) Compared with the near desert regions, the ratio of xerophytes was higher in the Kumtag Desert, and the relic nature was more obvious. Special seed plant taxa and flora features were formed because of the particular Kumtag Desert environment.