滇东喀斯特植被恢复演替过程中物种多样性研究

Species Diversity in the Process of Vegetation Succession in the Karst Area in Eastern Yunnan

将滇东喀斯特石漠化地区植被自然恢复演替过程分成草丛阶段、草灌阶段、灌木林阶段、次生乔林阶段、滇石栎和高山栎林阶段、麻栎和高山栎林阶段、高山栎林阶段.以空间代替时间选取典型样地,分析了各演替阶段群落的物种组成;应用物种丰富度、Simpson指数、Shannon指数和均匀度指数分别研究各演替阶段草本层、灌木层、乔木层和群落总体的物种多样性.结果表明:滇东喀斯特地区植被恢复演替过程中,草本层和灌木层物种多样性表现为波浪式前进趋势;乔木层的多样性先上升到滇石栎和高山栎林阶段达到最大,然后下降并逐渐趋于稳定;群落总体的多样性也表现为先上升后下降的变化趋势.除滇石栎和高山栎林阶段灌木层的多样性大于草本层外,其余各阶段均为草本层多样性大于灌木层并大于乔木层,乔木层多样性最低.云南松作为乔、灌层的先锋种,作用突出;壳斗科植物则为乔木层的建群种.

The process of natural succession of restoring vegetation in Eastern Yunnan after rocky desertification in Karst area appearing was divided into the herbosa stage, the stage of herbosa-shrub, the shrub stage, the stage of subaltern tree forest, the stage of Lithocarpus dealbatus-Quercus aquifolioies forest, the stage of Sawtooth oak-Quercus aquifolioies forest and the stage of Quercus aquifolioies forest. Typical quadrats were set up by using space instead of time. Species composition was analyzed in each stage and the species diversity in the layers of herb, shrub, tree and community at different successional stages was measured by the methods of species abundance, Simpson index, Shannon index and Pielou＇s evenness index. The results showed that the species diversity in the herb layer and the shrub layer transformed in a waveform. The species diversity in the tree layer rose steadily when the succession developed from the shrub stage, reached the maximum in the stage of Lithocarpus dealbatus-Quercus aquifolioies forest, then decreased gradually and went to level off. The diversity of community rose firstly and then decreased gradually too. The species diversity in the tree layer was the least and that in the herb layer was bigger than that in the shrub layer in the process of natural succession except the stage of Lithocarpus dealbatus-Quercus aquifolioies forest. The action of Pinus yunnanensis for community was very outstanding. The plants of beech family were the chief dominant tree species.