濒危植物七子花种内与种间竞争的数量关系

The quantitative relation of intraspecific and interspecific competition in endangered plant Heptacodium miconioides

七子花为国家 2级重点保护植物 ,现野生资源极少。利用Hegyi单木竞争指数模型对分布在浙江天台山的七子花种群的种内、种间竞争关系进行定量分析。结果表明 :七子花种内竞争强度随着林木径级的增大而逐渐减小 ,种内竞争较之与其伴生树种间的竞争剧烈。七子花种内、种间竞争强度大小顺序为 :种内 >苦枥木 >红脉钓樟 >青钱柳 >青榨槭 >暖木 >细齿绸李 >柳杉>赤杨叶。竞争强度与对象木的胸径大小服从幂函数关系 ,利用模型可预测七子花种内、种间的竞争强度 ,从预测结果可知当七子花的胸径达到 2 0cm后 ,竞争强度变得很小 。

Heptacodium miconioides is a Chinese special monospermous plant under state Grade-Ⅱ protection and now the wild resource was few. Using Hegyi individual tree competition index model, the relation of intraspecific and interspecific competition in Heptacodium miconioides distributed at Tiantai mountain of Zhejiang Province was quantitatively analyzed. The results showed that the intraspecific competition intensity in Heptacodium miconioides decreased gradually with the increasing of forest tree diameter class and the interspecific competition in Heptacodium miconioides was stronger than those in associated tree species. The degressive order of the intraspecific and interspecific competition intensity in Heptacodium miconioides was interspecific competition, Fraximus insulsris, Lindera rubronewia, Cyclocarya paliurus, Acer davidii,Meliosma veitchiorum, Prumus vaniotii ,Crytomeria fortunei and Alniphylium fortunei. The relationship between the competition intensity and the diameter at breast height of objective tree obeyed power function. The intraspecific and interspecific competition intensity in Heptacodium miconioides could be prognosticated using the model. The predicated results showed that the competition intensity became small and the range was not too large when the diameter at breast height of Heptacodium miconioides reached 20 cm.