用GIS技术研究中国簇毛黄耆亚属（豆科：黄耆属）的地理分布式样

用ＧＩＳ技术设计和绘制了豆科黄耆属（Ａｓｔｒａｇａｌｕｓ Ｌ．）簇毛黄耆亚属在中中的地理分布图。以种类和县级分面为基本构图单元。分布图形均呈斑块状。分布式样提示出亚属是一个集中分布在横断山和喜马拉雅，适应于高寒山地的特化类群。根据地理公布直观图及有关统计分析，认为横断山是这个亚属的分布中心、分化中心和特有中心。公布式样和直观图还揭示出一些种之间、组之间有趣的替代现象。

Studies on Geographical Distribution Pattern of the Subgenus Pogonophace (Fabaceae: Astragalus ) in China Using GIS Technique

The geographical distribution maps of the subgenus Pogonophace (Fabaceae: Astragalus ) in China were designed and drawn using GIS cartographic technique. The species of the subgenus and county of China were treated as the basic composition units in the GIS cartographic technique. Most of the distribution maps were shown in spots. The distribution pattern of the subgenus illustrates that it is a peculiar group to adapt the cold alpine environment and distribute mainly in Hengduan Mountains and Himalayas. According to the geographical distribution maps and some statistic analyses, Hengduan Mountains region is suggested to be the distribution center, differentiation center and endemic center of the subgenus. Some vicariance traces at levels of the species or sections are very interesting among the distribution patterns of the subgenus and shown clearly in the maps.