两种园林绿化植物的分枝格局

Branching Structures of Two Garden Plants

了解并研究绿化植物夹竹桃（Nerium indicum Mill）和鸡蛋花（Plumeria rubra cv acutifolia）的生态空间利用能力,旨在更好地制定、实施种植培育策略.以校园种植的夹竹桃与鸡蛋花为研究对象,各选取样木分别采用分枝结构参数分析法,以及WEB模型水平分枝法进行测量分析,在此基础上,探讨这两种园林绿化植物的分枝结构特征.研究结果表明：①不同基径大小的夹竹桃和鸡蛋花分枝数目普遍为4～5枝,两种植物的总体分枝率均在0.90～1.10之间,分枝能力基本一致.②夹竹桃各级分枝长度所表现出的组间差异性整体上要比鸡蛋花情况复杂.各级基径大小的夹竹桃平均分枝角度变化范围在34.00°～46.33°之间,鸡蛋花的平均分枝角度变化范围在56.00°～78.33°之间,且两种植物各级分枝角度在组间的差异较小.③根据WEB模型的假设计算夹竹桃和鸡蛋花的分枝半径指数a和分枝长度指数b值,结果显示夹竹桃a均为正值,且与理论值1/2不存在显著差异;而鸡蛋花的a则均与理论值差异显著.然而夹竹桃和鸡蛋花的b值,由于存在子枝分枝长度大于母枝分枝长度的情况,因此得到的结果出现异常负值,与WBE模型假设存在出入.

The abilities of utilizing ecological space of oleander （Nerium indicum Mill） and frangipani （Plumeria rubra cv acutifolia） were studied to formulate and implement the planting and cultivation strategy preferably. Sample individuals were chosen respectively and analyzed by using horizontal branching structure parameters method and WEB model analysis method. On this basis, the branching structural characteristics of the two plants were probed into. The results show that：①Different basal diameter of oleander, frangipani had the similar branching number, which was mostly 4-5. And both of the overall bifurcation ratios were between 0. 90 and 1. 10, the branching probabilities were basically the same. ②The branching length of differences between groups of oleander was more complex than that of frangipani as a whole. The mean branching angle of different basal diameter of oleander was between 34. 00°-46.33°, and the mean branching angle of different basal diameter of was between 56.00°-78. 33°. The differences of the two plants＇ branching angle between groups are small at all levels.③The branching radius index ＂a＂ and the branching length index ＂b＂ of oleander and frangipani are calculated according to WEB model, the results indicated that, ＂a＂ value of oleander were all positive, and there were no differences with the 1/2 of theoretical value; while all ＂a＂values of frangipani appeared significant differences with the theoretical value. However, due to existing situations that secondary branches were longer than primary branches, ＂b＂ values of both oleander and frangipani exhibited abnormal negative, this had a discrepancy with the assumption of WEB model.