海南岛尖峰岭卵叶樟种群结构与分布格局动态研究

卵叶樟(Cinnamomum rigidissimum H. T. Chang)是樟科(Lauraceae)樟属(Cinnamomum Trew)植物,是第一批被列入<国家重点保护植物名录>的二级重点保护物种1],具有重要的经济和科研价值.根据以往调查,卵叶樟在海南尖峰岭的数量较少,一般生长在海拔6001 000 m的热带山地雨林中,这与森林商业性采伐和盗伐等人为干扰活动导致森林环境变迁有关2-3].种群是群落构成的基本单位,种群结构不仅对群落结构有直接影响,而且能客观地体现群落的发展趋势4].研究种群空间格局及其动态可为研究森林群落演替趋势、森林生态系统可持续经营提供基础理论,其数量分析指数还可为生物多样性保护、森林可持续经营评价等提供可靠依据5].本文通过探讨卵叶樟种群结构和分布格局及其动态的数量特征,为探讨其濒危机制及合理保护提供理论依据.

The Population Structure and Distribution Pattern of Cinnamomum rigidissimum in Jianfengling, Hainan Island

Contiguous grid quadrates method was used to set up permanent plot to analyze the population structure and distribution pattern of Cinnamomum rigidissimum in Jianfengling, Hainan Island. The results show that the age structure of C. rigidissimum follow a pyramid form. And it is a steady increasing population with relatively more young trees. For the population distribution pattern, the number of individuals from seedling to big tree reduces step by step. And only few individuals can become big trees. At the stage of big tree, the competitiveness of C. rigidissimum enhances and mortality decreases. The number of survival individuals in the stage of super big tree are larger than those in the stage of big tree. The dynamics of population distribution pattern of C. rigidissimum changes from aggregation to random, when trees grow up gradually. For the young trees, the population distribution follows a clump pattern, which is mainly decided by the biological characteristics of themselves and the environment conditions. For the big trees, the population distribution follows a random pattern, which is mainly decided by interpopulation competition and environmental resources conditions.