塔里木荒漠优势植物——胡杨种内、种间竞争研究

采用逐步扩大范围的方法确定影响对象木的邻体最佳竞争范围,利用Hegyi提出的单木竞争指数模型对塔里木荒漠优势植物———胡杨种内、种间竞争强度进行定量分析。结果表明,在胡杨群落中,对象木的最适竞争距离为6 m,胡杨种内、种间竞争强度随着植株径级的增大而逐渐减小,种内竞争较种间竞争剧烈。竞争强度与对象木胸径服从幂函数关系,从模型预测结果可知当胡杨胸径达30 cm以上时,竞争强度变化很小。因此,应在此前采取适当的人工疏伐措施来促进植株生长和增强生态系统的稳定性。

Intraspecific and Interspecific Competitions of the Dominating Plant Populus euphratica in the Desert of Tarim

The method of gradual area expansion and Hegyi's competition model for individual tree were adopted to quantitatively study intraspecific and interspecific competitions of the dominating plant Populus euphratica in the desert of Tarim.It was shown that in Populus euphratica community,the optimal competition distance of the target trees was 6 meters,the intraspecific and interspecific competitions of Populus euphratica gradually become weakened with the diameter classes of the trees increased,and the intraspecific competition was more intense than the interspecific competition.The relation between the competition intensities and the diameters of the target trees at breast height followed a power function and the results predicted by the model revealed that when Populus euphratica had a diameter at breast height was more than 30 cm,the competitions varied little in intensity.Therefore,thinning measures should be adopted to enhance the growth of the tree plants and reinforce the stability of the eco-systems.