海南岛热带山地雨林天然次生林的功能群划分

The identification of functional groups in a secondary tropical montane rain forest of Hainan Island,south China

热带林极高的物种丰富度使许多生态分析非常困难,把功能相似的物种划分为不同功能群,将为热带林的生态研究提供新的途径。以物种的7个功能特性因子(生长型、分布的海拔高度、分布的林型、木材密度、喜光性、演替地位和寿命)和9个林分结构因子(相对生物量、相对胸高断面积、相对树高、相对密度、相对频度、相对冠幅、相对更新数、相对死亡数和相对萌生数)为基础,应用数量化分析的方法,对海南岛典型的热带山地雨林天然次生林群落进行了功能群的划分。结果表明:(1)应用CCA分析林分结构因子时,可将山地雨林天然次生林的物种划分为6类功能群,它们的相对生物量、相对密度、相对频度、相对更新数、相对萌生数和相对死亡数等,随胸径和高度的增加而呈现有规律的变化;(2)应用CCA分析物种功能特性因子时,可将山地雨林天然次生林的物种划分为5类功能群,它们的功能特性都随演替过程而呈现有规律的变化;(3)在综合考虑两个不同角度CCA分析的基础上,最后将热带山地雨林天然次生林的物种共划分为11类功能群,它们能充分体现物种随胸径和高度结构的变化特点及其在演替过程中所处的阶段;(4)演替初期的灌木类功能群与各不同演替时期的乔木功能群共同分布于的中下层,但其大多处于死亡状态;(5)演替初期与演替中后期的乔木功能群则共同组成的主层林,但其死亡数量也较高。可见,海南岛热带山地雨林天然次生林目前正处不同功能群的激烈竞争阶段。

The difficulty of ecological analysis in tropical forests due to high species diversity is a big problem. Therefore, to aggregate species with similar functional traits into functional groups for analysis is a new way to solve the problem. In this study, based on the certain functional traits （growth form, succession status, longevity, wood density, shade tolerance, elevation and forest type） and stand structural characteristics （relative biomass, breast area, height, density, frequency, canopy size, regeneration, mortality and germination）, quantitative ordination analysis were used to identify the functional groups in this forest. Collected information is however summarized as follows ： （ 1 ） By applying CCA （ Canonical Correspondence Analysis） to analyze the factors of forest structure and species were classified into 6 functional groups, and changes were found in the related factors such as relative biomass, density, frequency, regeneration and mortality responding to the varieties of the diameters and heights of the stand; （2） By applying CCA to analyze plant functional traits, the species were classified into 5 functional groups and the related factors such as light demanding, succession status and wood density were found to be changing with the successional process ; （ 3 ） based on integration of twice CCA analyses, the species of the secondary tropical montane forest could be classified into 11 functional groups, which could well represent the change of species with the forest structure and successional stages of the stand; （4） the functional group of shrubs in the early successional stage, which mainly distributed in the under-storey layer of the forest, died almost completely, coexisting with the functional groups of other successional stages ; （5） the functional group of trees in the early successional stage also have high mortality, which distributed in the main canopy layer coexisting with the functional groups of the later successional stage. At present, the tropical montane secondary forest in Hainan island is in the intensive competitive stage of different functional groups.