荒漠植物持水力研究

持水力是表征植物耐旱性的一个重要指标。对62种荒漠植物，包括10种乔木、39种灌木和13种草本植物失水过程进行了测定，并对累计失水曲线进行逻辑方程的拟合，拟合方程的决定系数都在0.8以上。按照枝、叶构件所拟合的逻辑方程拐点不同，将荒漠植物分为弱持水型、中等持水型和强持水型。灌木和草本植物的持水能力较乔木植物强。从枝构件的分类结果分析，属于弱持水型、中等持水型和强持水型荒漠植物的植物种类依此为23种、26种及13种，说明多数植物枝条的持水能力不太强。而从叶构件的分类结果分析，依次有2种，19种和41种植物属于上述3种类型，说明大多数荒漠植物的叶片的持水能力较枝条强。

Water-retaining Capability of Desert Plants

Water-retaining capability is one of the important indexes that indicate drought resistance capacity of plants.The dehydration process of 62 desert plants,including 10 tree species,39 brush species and 13 herb species,were analyzed with fitting of Logistic curves, whose correlation coefficient are all more than 0.8.According to turn points(TP) distribution of different Logistic curves,those plants can be sorted into weak water-retaining capability type,medium water-retaining capability type and strong water-retaining capability type.The water-retaining capability of brush and herb species is stronger than that of tree species.Among the 62 desert plants there are 23 weak,26 medium and 13 strong species respectively based on classification of branch configuration,which indicates that the branch water-retaining capability of most species is not strong enough;whereas there are 2,19 and 41 species correspondingly according to classification of leave configuration,which suggestes that the water-retaining capability of leaves is stronger than that of branches.