菜阳河自然保护区山地雨林主要乔木种群分布格局研究

Spacial Distribution Patterns of Tree Populations in Montane Rain Forest in Caiyanghe Nature Reserve

采用方差/均值比的t检验法、负二项式分布指数K、平均拥挤度m、聚块性指数m x、丛生指标I、Morisita指数及最近邻体法对菜阳河自然保护区山地雨林的优势乔木种群的分布格局进行了研究。结果表明,该群落重要值在2.0以上的12种乔木种群中,4种呈聚集分布,8种呈随机分布,没有均匀分布。多数种群呈随机分布的状况表明,该群落已接近于演替的顶极期。各种群为争取更多的环境资源而随机分布在群落中,少数种群呈聚集分布则是由于生境的异质性或其本身的生物生态学特性引起的。在不同发育阶段,岭罗麦、光序肉实树的分布格局由聚集分布向随机分布过渡,滇南红厚壳则在不同的年龄阶段均呈随机分布。优势种群在不同发育阶段分布格局的变化,显示出它们在群落中为争夺有利的生长环境而长期竞争的关系。

Using the methods of t-test of s^2 ratio, negative binomial parameter K, mean crowding index, patchiness index, Morisita index and the method of nearest neighbor, the spacial distribution patterns of the main tree populations in montane forest in Caiyanghe nature reserve were studied. The results showed that among 12 main tree populations （important value 〉2.0） in the community, there were 4 populations showed clumped distribution and the other 8 populations were all randomly distributed, no one showed uniform distribution. The fact of most populations were random showed the community had been close to climax of succession, in these populations could get more environmental resources only when distributed randomly. Some populations showed clumped distribution was due to the different conditions or the biological and ecological characteristics of their own. In different stages of development, spatial distribution patterns of Rubia wallichii and Sarcosperma kachinensis var. simondii changed from clump to random, however that of Calophyllum polyanthum kept random all the time. The variation of spatial patterns of dominant populations in different times reflected their competitive relationship in scrambling for more environmental resources.