海南岛甘什岭特有植物无翼坡垒种群结构与动态

无翼坡垒（Hopea reticulata）又称铁凌、铁垒,为中国特有种、国家二级重点保护植物,仅自然分布于海南三亚市崖州区与保亭县交界的甘什岭一带,但在分布区域内,其种群密度很大,并形成了一片以它为优势的单优热带雨林。对海南岛甘什岭无翼坡垒天然种群进行调查,通过建立种群静态生命表,绘制种群存活曲线描绘该种群的结构特征,利用种群数量动态预测和时间序列分析法定量探究其未来的发展走势。结果显示,海南岛甘什岭无翼坡垒种群发展稳定,为增长型种群。种群静态生命表分析表明,无翼坡垒种群Ⅱ龄级小树阶段个体死亡率较低,Ⅲ龄级中树阶段死亡率最高;种群存活曲线趋向于Deevey-Ⅱ型;死亡率和消失率曲线变化趋势一致。生存分析表明,无翼坡垒种群具有前期生长状况良好,中期竞争压力大,后期整体发展趋于平缓的特点。时间序列预测结果表明,发展成熟的无翼坡垒种群其抵抗力稳定性较强,一旦度过了由Ⅲ龄级中树阶段向Ⅳ龄级老树阶段发展的过渡期,其种群便能十分稳定地发展。因此,建议在目前建立自然保护区的基础上,加强对无翼坡垒中龄植株的保护,提高存活率,使其能有更多数量的个体进入下一龄级的生长发育阶段,有利于该种群的发展壮大。

Population Structure and Dynamics of Hopea reticulata,a Plant Endemic to Ganshiling,Hainan Island

Hopea reticulata is an endemic specie of China and the second-class national key protected plant. It is only naturally distributed in Ganshiling Region where is at the junction of Ya County and Baoting County in Hainan. But it has a high population density and forms a single dominant tropical rainforest with itself as advantage. In order to investigate the natural population of H. reticulata in Hainan Ganshiling, we drew the population survival curve and described the features of the population structure by means of establishing the static life table of this population, as well as conducting the quantitative study on its future development trend with the use of dynamic prediction of the population quantity and time series analysis. The results showed that the development of H. reticulata population in Hainan Ganshiling was stable, which is the growth form population. The analysis of population static life table indicated that the individual death rate of H. reticulata population in the stage of Ⅱ age-class sapling was low, and the death rate in the stage of Ⅲ age-class medium-sized tree was the highest; the population survival curve tended to Deevey -Ⅱ type; the curve of death rate and disappearance rate showed a consistent variation trend. The survival analysis showed that the H. reticulata population had the characteristics of well growth in the early stage, high competition pressure in the middle stage and gentle growth tendency in the late stage. The result of time series prediction indicated that the well-developed H. reticulata population had better stability of resistance, once going through the transitional period from the stage of Ⅲ age-class medium-sized tree to the stage of Ⅳ age-class grown tree, the population could develop very steadily. Therefore, it is suggested that on the basis of establishing nature reserves at present, the protection of middle-aged plants of H. reticulata should be strengthened to improve the survival rate and enable more individuals to enter the growth and development stage of the next age class, so as to ensure the normal renewal of the population.