元宝山两类森林群落的乔木物种多样性

TREE SPECIES DIVERSITIES OF TWO FOREST COMMUNITIES IN YUANBAO MOUNTAIN

对元宝山保存的广西最古老、最原始、最完整的常绿落叶阔叶混交林和针阔混交林进行了乔木层物种多样性研究 .结果表明 :1)两类群落的物种多样性特征和群落各物种的重要值变化以及群落优势度反映出来的特征相一致 ;2 )物种重要值和个体数作为测度指标所得结果相近 ;3)随着面积由 5 0 0～ 30 0 0m2 的变化 ,物种多样性指数差异不大 ,标准差和变异系数均较小 ,在不受面积大小影响 ,正确反映群落多样性方面 ,Shannon -Wiener指数优于Simpson指数 ;4 )常绿落叶阔叶混交林和针阔混交林的多样性指数均较高 ,Shannon -Wiener指数分别为 5 .35 0 7和 4 .5 395 ,与北热带季节性热带雨林、南亚热带季风常绿阔叶林和中亚热带典型常绿阔叶林物种多样性比较 ,未表现出明显的纬度梯度特征 .图 4表 4参 2

Tree species diversities of evergreen-deciduous broad leaved forest and coniferous broad-leaved forest in the Yuanbao Mountain which are the most antient,primal and intact forests in Guangxi were studied. The results showed that (1) the tree species diversity characters of the two communities accorded with the characters reflected by their species importance value variation and community dominance index; (2) the results were similar to those when IV (important value index) and individuals were used to measure community diversity; (3) the diversity indices did not show evident difference with variation from 500～3 000 m 2 of the plot area,especially Shannon-Wiener index,which indicated it was superior to Simpson index in the aspect of community diversity; (4) the diversity indices in evergreen deciduous broad-leaved forest and coniferous broad-leaved forest were both high,compared with those of the north-tropical seasonal rain forest in Yunnan Province,the south-subtropical seasonal monsoon evergreen broad-leaved forest and med-subtropical typical evergreen broad-leaved forest of Guangdong Province,indicating that the species diversity had no evident character of altitude gradient. Fig 4,Tab 4,Ref 20