滇南片断热带雨林植物物种多样性变化趋势

The changing tendency of plant species diversity in the fragmental tropical rainforest in Southern Yunnan,China

采用群落样方（５０×５０ｍ）调查分析法，探讨滇南西双版纳曼仰广龙山片断热带雨林群落中木本植物物种多样性１９５９～１９９１年间的变化趋势。结果表明，该片断森林经３０多年的演化，物种数变化不大，但物种多样性指数降低２４％。在片断热带雨林中，物种的消失率与新增率虽相对平衡，但由于物种的生物学、生态学特性不同，呈现明显的消长变化趋势，即：在群落的不同层次中，物种消失率和新增率都是乔木（Ａ．Ｂ．Ｃ）＜灌木（Ｄ），在乔木层中则是Ａ＜Ｂ＜Ｃ；就物种的不同确限度而言，消失率和新增率都是特征种＜适宜种＜随遇种＞外来种。此外，本研究认为群落内小气候由“凉湿效应”向“干暖效应”转化，是片断热带雨林物种多样性变化的一个重要环境因素。

he changing tendency of woody plant species diversity in 1959～1991 was investigated by the method of survev and analvsis of community sampling(50 ×50 m )in fragmental tropical rainforest of Manyangguang Holy Hill Forest,Yunnan. The result of the research showed that the species number has a slight change over 30 years in the fragment,while the index of species diversity decreases by 24%。Even if the disappearing rate and increasing rate of species in the fragment are relatively equivalent over 30 years,they have obviously changing tendency due to the biological and ecological characteristics of species:both species disappearing rate and increasing rate in arbor plant(storey A.B.C)are higher than shrub(story D);while in the arbor storeys,A>B>C. On the other hand,both species disappearing rate and increasing rate in different species exclusiveness of communities are:character species<preferrent species<indifferent species>exotic species.Moreover,the microclimate of the fragment changed from“cool and wet effect”to“dry and warrn effect”is one of the important environmental factors which make the change of species diversity.