Species Diversity of the Main Forest Community Undergrowths in the Huanglong Mountain

Through typical plots investigation,species diversity indices,richness indices and evenness indices of the shrub layers and the herb layers of the main forest communities in the forest stands(Quercus liaotungensis forest, Pinus tabulae formis forest,Betula platyphylla forest,P.stabulae-Q.liaotungensis mixed forest,Q.liaotungen- sis-B,platyphyUa mixed forest and P.stabulae-B.platyphylla mixed forest)in the Huanglong Mountain forestry region in Shaanxi Province,were systematically studied.The results showed that:1)the species diversity indices, richness indices and evenness indices of the shrub layers of the main forest communities in the forest stands were higher than those of the herb layers.It demonstrated the importance of the shrub layers in the temperate zone forest communities;2)In the six forest communities,the shrub layers and the herb layers of Q.liaotungensis forest showed the highest species diversity and the B.platyphylla forest showed the lowest species diversity.It revealed that the Q.liaotungensis forest was the main vegetation and the B.platyphylla forest which tended to degenerate would be substituted by other forest communities;3)The species diversity indices,richness indices and evenness indices of the shrub layers and the herb layers of the six forest communities on the sunny slope in the forest stands were higher than those on the shady slope.The reason was that the environment factors of the sunny slope such as light,heat,temperature,water and so on were better than those on the shady slope.In the future forest manage- ment,reasonable measures should be adopted according to the characteristics of species diversity in the Huanglong Mountain to achieve economical and ecological benefits.