阿拉善高原荒漠植被组成分布特征及其环境解释:Ⅱ.C_4植物组成、分布特征与环境的关系

研究了阿拉善典型干旱荒漠植被区C4植物的组成特征、空间分布及其与环境因子的相关性。发现C4植物主要集中在藜科(Chenopodiaceae)和禾本科(Gramineae),生活型以一、二年生草本为主,占到70%以上;旱生和旱中生C4植物所占比例较大,达到48.89%,其区系成分以世界成分、亚洲中部成分和古地中海成分为主。C4植物分布特征表现出不同的规律性:在垂直地带分布上与温度呈正相关关系、与降雨呈负相关关系;在水平经度地带分布上主要与降水呈正相关关系,与温度无显著相关,尤其是在极端高温、干旱(主要是额济纳戈壁荒漠区)地区,C4植物的生存受到了限制。这一结果对于揭示阿拉善地区C4植物的水分利用效率,及其与降水资源的空间分布之间的关系提供了一定的理论解释。

Environmental Effects on Distribution and Composition of Desert Vegetations in Alxa Plateau:Ⅱ.Correlation between C_4 plants distribution and environmental factors

This study aims to provide an analysis of vegetation and environment relationship in the Alxa Plateau of Inner Mongolia,China.Seventy species representing 46 genera and 16 families are collected.The largest families are Leguminosae,Polygonaceae,Gramineae and Compositae,representing 200%,157%,143% and 143% of the total flora,respectively.Phanerophytes and hemicryptophytes are the most abundant life form.Classification of the vegetation is conducted by using two-way indicator species analysis(Twinspan)techniq...