贺兰山东坡低山区植被种类组成区域分异与植被性质的分析

本文以定量和定性分析相结合，分析了贺兰山东坡海拔1200—1900m低山区范围内植被种类组成的区域分异、植被性质及生态条件的区域分异特点。结果表明，该范围内务主要植被类型具有荒漠草原或荒漠草原化的共同特点，其种类组成均在北、中、南不同地段存在一定差异。此差异反映出本区海拔1600m以上的中部地段及其以下的北部地段分别是生态环境最湿润和最干旱的区域．

ANALYSIS OF THE REGIONAL DIFFERENCES OF FLORISTIC COMPOSITION AND THE NATURE OF VEGETATION IN THE LOWER ZONE ON THE EASTERN SLOPE OF THE HELAN MOUNTAIN RANGE

In this paper, by using quantitative and qualitative methods, the regional differences of floristic composition and the nature of vegetation in the lower zone on the eastern slope of the Helan Mountain Range have been analysed, and the relationship between the species groups as a result of the ordination and ecological environments in the zone has also been discussed. The resuls of analysis show that all the main forms of vegetation in the zone have the common characters of desert or desertified steppe vegetation and the composition of the vegetation is different in the northern, middle and southern parts of the zone. Those differences reflect that, in the zone, the most humid area and the most arid area are respectively the middle part above the altitude of 1600 meters and the northern part below it. Therefore, in the zone,it is necessary to make use of and to conserve the vegetation resources in different ways.