摘要
对黑石顶自然保护区森林次生演替过程中的群落结构、物种组成及物种多样性变化的研究结果表明：在皆伐裸地恢复阶段最初的２～４ 年，先锋种、阳生性种及中生性种的幼苗同时大量出现于次生裸地上；演替至１０ 年时，群落中先锋种的数量占绝对优势，阳生性种保持稳定，中生性种趋于减少；针阔叶混交林阶段，先锋种趋于减少，阳生性种趋于增加；阳生性常绿阔叶林阶段，先锋种基本衰退，而阳生性种占绝对优势，同时中生性种趋于增加；演替至中生性常绿阔叶林阶段，阳生性种逐渐消退，中生性种的数量占优势。皆伐裸地恢复阶段为群落垂直结构的形成期，仅有Ⅲ级以下立木，乔木层无明显分层，群落的个体密度无明显变化；由恢复阶段进入针阔叶混交林初期为群落垂直结构分化期，群落中出现大量Ⅲ、Ⅳ级立木，乔木层可分为３ 个亚层，但群落的个体密度因自疏作用而显著下降；针阔叶混交林阶段为群落垂直结构的相对稳定期，Ⅴ级立木多度和胸高断面积呈演替系列的第一个高峰，同时群落的个体密度显著增大；阳生性常绿阔叶林阶段为群落垂直结构的变动期，群落中Ⅴ级立木多度和胸高断面积大幅度下降，个体密度无明显变化；中生性常绿阔叶林阶段为群落垂直结构的稳定期，群落中各立木级趋于更加完善。
Studying on the community structure, species composition and species diversities of the secondary succession of lower subtropical forest in Heishiding Natural Reserve, Guangdong Province, the following results were obtained. In 2～4 years of restored stage the seedlings of pioneer species, heliophytes and mesophytes occur simultaneously. In 10 years of restored stage pioneer species are superior as heliophytes maintain stable and mesophytes are being decreased. In the stage of mixed forest pioneer species are on the decreasing and heliopytes are on the increasing trend. In the stage of evergreen broad_leaved forest dominated by heliophytes pioneer species are being declined, heliophytes are dominant and mesophytes are being increased. In the stage of evergreen broad_leaved forest dominated by mesophytes heliophytes are being declined and mesophytes are superior. The vertical structure, horizontal structure, the structure of species composition determine stability of communities in secondary succession process. The vertical structure of community is building up in the stage of restoration. The community is composed of the stands under the third class. The forest canopy is not stratified. The individual density is stable. From restored stage to mixed forest the vertical structure of community is diversified. There are the third and forth class stands in community. The tree layer is divided into three sub_layers. The individual density declines rapidly because of self_thinning. In the mixed forest the vertical structure is relatively stable. The abundance of the fifth class stands and area of breast height reach the first peak in the succession serial. The individual density increases rapidly. In stage of evergreen broad_leaved forest dominated by heliophytes, the vertical structure changes largely. The abundance of the fifth class and area of breast height decline rapidly, but the individual density changes slowly. In the stage of evergreen broad_leaved forest dominated by mesophytes, the vertical structure of community is stable and the composition of every stand class becomes more stable. The area of breast height is the biggest in the succession serial. When succession develops, the coverage of communities increases gradually but the turnover rate of species declines. The species composition tends to be stabilized. The diversity of species and community evenness increase gradually thus, the ecological dominance declines gradually.
基金
国家自然科学基金
关键词
森林群落
次生演替
群落动态
Forest communities, Secondary succession, Community dynamic
