民勤荒漠植物枝系构型的分类研究

荒漠植物的枝系构型因素包括各级分枝角度、各级分枝长度、枝径比、逐步分枝率和总体分枝率、分枝分维数和计盒维数等16个指标。采用组内欧式距离法进行聚类，把荒漠植物依构型指标分为4个类型：第一类型包括霸王（Zygophyllum xanthoxylum）、黄刺条（Caragana frutex）等14种荒漠植物；第二类型包括秦晋锦鸡儿（C．purdomii）、荒漠锦鸡儿（C．roborovskyi）等11种荒漠植物；第三类型包括网状沙拐枣（Calligonum cancellatum）、黄花草木樨（Melilotus suaveolens）等9种荒漠植物；第四类型包括扁果木蓼（Atraphaxis replicta）、洋白蜡（Frawinus amerirana）等14种荒漠植物。不同的枝系构型类型反映了不同荒漠植物对于空间资源与环境的长期适应对策。

Classification of the Branching Architectures of the Desert Plants in Minqin County

There are sixteen parameters in the branching architectures of desert plants such as branch length and branching angle at different branching levels,branch-stem ratio,stepwise bifurcation ratio(SBR),overall bifurcation ratio(OBR),branching dimension and fractal dimension and box-counting dimension.The cluster analysis of the interclass Euclidean distances divides the parameters in the branching architectures of the desert plants into four types,the frist types including fourteen desert plants such as Zygophyllum xanthoxylum and Caragana frutex,the second type containing 11 desert plants including C.purdomii and C. roborovskyi,the third type consiting of 9 desert plants such as Calligonum cancellatum and Melilotus suaveolens,and the fourth type being composed of fourteen desert plants including Atraphaxis replicta and Fraxinus americana.The different branching architectures reflect the long-term adapting strategies of the different desert plants to spatial resources and environments.