Species Diversity Characteristics of Rhododendron Community in the Sejila Mountain in Tibet

In this paper the research is directed toward the rhododendron community which are distributed in the Sejila mountain in Tibet.Species diversity characteristics of rhododendron community were analyzed by spot-quadrat investigation method.The results indicated that there were 14 species of woody plants in shrub layers.The species diversity indexes decreased with the altitude increasing.There were 40 species of herbs in ground layers,and the herb diversity indexes on sunny slope were higher than those on shady slope.The species diversity of the ground layer was more or less than that of shrub layer in rhododendron community.The difference of diversity indexes was relatively small in shrub layers,but it was larger in ground layers.The Patrick index,Shannon-Wiener index,N1 index between shrub layers and ground layers had no significant difference,Simpson and N2 indexes had a significant difference,and Pielou and Heip indexes had a very significant difference.The research results showed that the environment conditions had a large influence on the species diversity of rhododendron community.The research results established the foundation for protecting and managing the rhododendron resource.