The community diversity at different secondary successional stages on the abandoned cropland in Taibaishan,the peak of Qinling Mountains,was measured and studied using the methods of species abundance,Shannon Wienner index,Pielou's evenness index and Alatalo evenness index.The results show that the diversity indices arose steadily when the succession developed from the annual herbosa to the mixed broad leaved deciduous forest,After the stage of the mixed broad leaved deciduous forest,the indices decrease...