Abstract:

In order to understand the species structure and diversity of vegetation communities around 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.-Schima 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 species diversity 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 suggested that plant diversity index could be predicted by the mid-domain effect (MDE).