Abstract: This paper discussed about species richness,species diversity index and evenness of higher plants of the Heptacodium miconioides community in the Tiantai Mountain of Zhejiang Province.The results showed that the species richness and species diversity index of the woody plants were obviously higher than those of the herbs, but there was no significant difference in the evenness. The relation between life form and species diversity of the plant showed that species richness and species diversity index of both the tree layer and shrub layer were higher than those of the herb layer. The difference of the evenness among the three layers not distinct. The diversity indexes of tree layer, shrub layer and herb layer was varied in the nine plots community. The variation in herb and shrub layer were significant, but relaively less in the tree layer.

Key words: biological soil crust, erosion region, acetylene reduction assay (ARA), nitrogenase activity, environmental factor.