论草划原区和荒漠草原区在宁夏东部的界限

 以盐池县为主的宁夏东部草原地区，地处典型草原向荒漠草原的过渡地带，饲养着全自治区近五分之二的二毛裘皮滩羊，是区内重要的畜牧业生产基地之一。这一地区在1955—1961年间曾由不同的专业队进行过多次自然资源综合考察6,8,10,17]，主要单位有中国科学院黄河中游水土保持综合考察队，中国科学院治沙工作队，中国科学院内蒙古宁夏综合考察队以及自治区综合勘察队和宁夏农学院等。虽然积累了一些有关这一地区草原植被方面的资料，但正式发表的不多，并且在草原界线的划分上由于认识的不同，分歧较大。如划分界线时有的主要考虑地形或土壤因子8]，而对植被本身的差异注意得不够，甚至建群针茅的种类也还没有搞清楚17];还有的把隐域植被(沙生植被)与地带性植被混同起来，并过分强调少量入侵的荒漠植物(刺叶柄棘豆)的作用。1977年以来我们连续在这一地区进行草场植被资源调查和草原生态定位研究，现就我们的认识对宁夏东部草原的属性、界线及其资源特征，提出一些看法。

Demarcation Line and Principal Character of Steppe Vegetation Types in the Eastern Part of Ningxia

Under climatic conditions of semi-dry and near warm temperate zone steppe in the eastern part of Ningxia, situated in the transitional region between typical steppe and desert steppe. There are different points of view concerned with the demarcation line between these two steppes. In accordance with structure and component of the vegetation, distribution and sere of Stipa bungeana and Stipa breviflora steppe. The demarcation line between these two steppes has been suggested. Besides, how to divide the line in the transitional region of steppe and its meaning in the use of grassland were described.