木荷种群优势度增长动态规律研究

为了能够客观地表现种群消长的动态模式,以胸高断面积代替种群生物量,采用洪伟等提出的Logistic改进模型对木荷(Schima superba)种群的增长动态进行研究,运用改进单纯形对模型参数进行优化。拟合结果表明,木荷种群的最大增长速度出现在第4龄级至第5龄级之间,即胸径为32.5~42.5 cm时期。在所调查的林分中木荷种群基面积已达到17.463 7 m2/hm2,而木荷种群的平衡位置是基面积为15.031 1 m2/hm2的点,表明目前木荷种群还处在演替阶段,达到平衡状态还要经过一段时期。

Growth Dynamics of Dominance of Schima superba Population

In order to display the dynamic mode of population's growth and decline objectively,In this paper,Hong-Logistic model is proposed to approach the growth of tree basal area of Schima superba population.The method of modified model simplex was applied to optimize the parameters of the model,and the fitting results showed that Hong-Logistic model was suitable to display the actual growth trend of S.superba population,and the highest growth rate of basal area was between the forth and the fifth age classes,namely the phase when breast diameter was 32.5~42.5 cm.The population's basal area reached 17.463 7 m~2/hm~2 in the forest investigated,but the balance position of the population was at the point of 15.031 1 m~2/hm~2,which indicated that the population was in the stage of succession,and it would take some time for the population to reach the balance state.