元阳梯田核心区周边森林群落植物多样性研究

为了了解元阳梯田核心区周边植被群落物种、结构特征及多样性，揭示元阳梯田核心区周边森林群落结构及多样性特征，为元阳梯田核心区周边森林群落进行合理保护和利用提供依据，笔者通过样方法对元阳梯田核心区周边森林群落进行野外调查，利用物种丰富度指数、Shannon-Wiener指数、Simpson指数、Pielon均匀度指数、生态优势度等多样性指数，对森林群落植物多样性进行研究。结果表明：（1）草本层植物种类91种，灌木层67种、乔木层42种。草本层多样性最大，其Shannon-Wiener指数和Simpson指数分别为0.82、0.98、均匀度指数为0.18；灌木层多样性最小，Shannon-Wiener指数和Simpson指数分别为0.32、0.87、均匀度指数为0.08；（2）14个群落中，鸭公树-木荷群落多样性最大，其Shannon-Wiener指数和Simpson指数分别为1.38、0.92，均匀度指数为0.36；云南松群落多样性最小，Shannon-Wiener指数和Simpson指数分别为0.42、0.37，均匀度指数为0.16。不同群落类型间的多样性大小次序为：阔叶林群落>人工林群落>草地群落>针叶林群落；（3）多样性指数随海拔梯度变化，呈先增大后减小的变化趋势，其最大值出现在1850 m，体现了“中度膨胀“的垂直分布格局。

Species Diversity of Plant Communities Around Core Area of Yuanyang Terrace

In order to understand the species structure and diversity of vegetation communmes arouno core area of Yuanyang terrace, reveal the characteristics of the forest community＇s structure and diversity, provide the basis for protection and rational use of plant communities around core area of Yuanyang terrace, the relationships between species diversities in different plant communities in Yuanyang County were studied with richness index, Shannon-Weiner index, Simpson index, evenness index and ecological dominance. The results showed that： （1） some 91 species were in herb layer, 67 species in shrub layer and 42 species in tree layer. The highest species diversity index, which was Shannon-Wiener index 0.82, Simpson index 0.98 and evenness index 0.18, was observed in herb layer. The lowest species diversity parameters, which was Shannon-Weiner index 0.32, Simpson index 0.87 and evenness index 0.08, was observed in shrub layer. （2） In 14 plant communities, the highest species diversity parameters, which was Shannon-Wiener index 1.38, Simpson index 0.92 and evenness index 0.36, was observed in Neolitzea chuii Merr.-Sehima superba Gardn et Champ community. The lowest species diversity parameters, which was Shannon-Weiner index 0.42, Simpson index 0.37 and evenness index 0.16, was observed in Pinus yunnanensis Franch. community. The order of speciesdiversity parameters was broad-leaved forest community〉tea garden community〉grassland community〉 coniferous forest community. （3） Plant diversity index first increased and then decreased with elevation gradient. The maximum plant diversity index appeared approximately in elevation 1850 m. It was that plant diversity index could be predicted by the mid-domain effect （MDE）. suggested