濒危植物泰山柳种内与种间的竞争关系

以整合的基径代替胸径,采用Hegyi单木竞争指数模型对灌木泰山柳进行种内与种间的竞争关系分析。结果表明:泰山柳的种内、种间竞争强度分别占总竞争强度(86.11)的35.01%、64.99%,说明泰山柳的竞争压力主要来自种间。随着泰山柳基径的增加,种内、种间竞争强度均逐渐降低。对泰山柳产生竞争影响的树木共9种,其竞争强度为泰山柳>花楸树>紫椴>油松>连翘>湖北海棠>天目琼花>金花忍冬>巧玲花。整个林分和伴生树种竞争指数都与对象木基径近似地服从幂函数关系(I C=AB-K),根据函数模型可以看出,当泰山柳基径达到10 cm后,竞争强度趋于平稳,而基径小于10 cm的泰山柳竞争强度激烈,可以清除其周围部分竞争木,给予足够的生存空间,从而达到保护的目的。

Intraspecific and interspecific competition of the endangered plant Salix taishanensis

The intraspecific and interspecific competition intensities of the shrub plant,Salix taishanensis,were analyzed using Hegyi′s single-tree competition index model and integrated basal diameter instead of diameter at breast height.The intraspecific and interspecific competition intensity of Salix taishanensis accounted for 35.01%and 64.99%of the total competition intensity(86.11),respectively,indicating that interspecific competition had a larger effect.The competition intensity of Salix taishanensis gradually increased along with basal diameter.There were nine main species of tree that exerted a competitive influence on Salix taishanensis.For those nine species,the competition intensity of intraspecific and interspecific competition with Salix taishanensis were ranked in the following order:Salix taishanensis>Sorbus pohuashanensis>Tilia amurensis>Pinus tabuliformis>Forsythia suspensa>Malus hupehensis>Viburnum opulus var.calvescens>Lonicera chrysantha>Syringa pubescens.The relationship of the basal diameter of objective trees and the competition intensity between competitive trees and objective trees in the whole forest and other competitive trees nearly conformed to the power function(I C=AB–K).According to the prediction of the model,when the basal diameter of Salix taishanensis reached 10 cm,the competition intensity tended to be stable.Salix taishanensis trees whose basal diameter was less than 10 cm,were under strong competition pressure,while for individuals whose basal diameter was less than 10 cm,some of the surrounding competitive trees could be removed to give them enough living space,and thereby conserve the species.