退化喀斯特森林自然恢复过程中的冠层结构特征及其动态变化

Structurd characteristics and dynamic changes of canopy in the process of natural restoration in degraded Karst forest

采用空间代替时间的方法,利用CI-110冠层分析仪研究退化喀斯特森林不同恢复演替阶段（灌木林阶段、灌乔林阶段、乔木林阶段和顶极群落阶段）的森林群落冠层结构特征及其动态变化。结果表明：1）在不同恢复演替阶段的森林群落冠层结构变化中,叶面积指数变化范围为1.56~2.92,其值的变化规律是从灌木阶段到顶极群落阶段,先减小后增大,但只有乔木林阶段与其他几个阶段达到差异极显著水平;2）在不同恢复演替阶段的平均叶倾角变化差异均不显著;3）冠层空隙度的变化中,灌木林阶段、灌乔林阶段和顶极群落阶段的变化差异均不显著,乔木林阶段的值最大,与其他几个阶段的变化差异达到极显著水平;4）对几个冠层结构指标进行相关性分析,叶面积指数与冠层空隙度之间存在着极显著的负相关关系。

By employing the method of using space as a substitute for time, we studied the characteristics of canopy structure and dynamic changes of forest communities at different restoration/succession stages of degraded Karst forest, namely, shrub stage, shrub-tree stage, tree stage and climax stage, using a CI- 110 Plant Canopy Imager. The results show that： 1 ） Among the changes of forest canopy structure in different succession stages, leaf area index ranged between 1.56 and 2.92, and its value initially decreased and then increased from shrub stage to top climax stage, and only at tree stage did it achieve extremely significant differences with that of other stages. 2） There were no significant differences in the variations of mean leaf angle at different succession stages. 3） The variations of canopy gaps were not significant among the shrub stage, the shrub-tree stage, and the climax stage. It reached the maximum value at the tree stage, and there existed extremely significant differences between the tree stage and other succession stages. 4） The correlation analysis of several indexes of canopy structure showed that there was a highly significant, negative correlation between leaf area index and canopy gap.