印楝人工林对植物多样性的影响

以种植在元谋不同年龄的印楝林为研究对象,对林内的植物群落种类组成进行区系分析,结果表明群落内的植物种类以泛热带分布和全世界分布为主。用Gleason丰富度指数、Simpson和Shannon Weiner多样性指数、Pielou均匀度指数对调查样地多样性进行分析,获得如下结果:(1)生物多样性指数随印楝林盖度的提高而逐渐下降,说明盖度是影响林下植物多样性的主要因子;(2)印楝林对林下植物多样性影响主要通过林荫,印楝盖度<40%时对林下植物多样性影响不明显,而当盖度>40%时,影响明显;(3)印楝林下植物生长好于对照,印楝枯枝落叶对林下植物生长没有抑制作用。

Influence of Azadirachta indica Plantation upon the Native Plant Diversity in Yuanmou County,Yunnan

Native plant species were studied in the neem(Azadirachta indica) plantation in Yuanmou County of Yunnan by analying the genus areal-types and four diversity indexes (Gleason index,Simpson's diversity index,Shannon-Weiner index and Pielou's evenness index). According to the genus areal-types, the main areal-types were Pantropic and Cosmopolitan , indicating that the tropical component was the most abundant.It was consistant with the climate of the Dry-Hot Valley in Yuanmou County. Four diversity indexes showed the same results: (1)the species richness, diversity indices and evenness declined with the increase of coverage of neem plantation; (2)the number of species and the number of each species were not influenced evidently by the shadow of neem plantation in low coverage(<40%),while this influence was very evident in high coverage(>40%); (3)the growth of other plant species was restrained by the defoliatation and deadwood of neem in the neem plantation, some species grew very well.