Community diversity features of different damaged stages in typical regions of Wenchuan earthquake affected area:A case study in Beichuan, Sichuan Province of southwestern China.

To study the characteristics of different damaged stages in typical regions of Wenchuan earthquake area, Sichuan Province of southwestern China, field surveys and laboratory experiments were carried out in Subaohe and Wenjiagou watersheds as typical regions of Wenchuan earthquake area, including four vegetation types of restored grassland, damaged forest, bare land and nonedamaged place. The results showed that different damaged communities had significant differences in species composition, species number, vertical structure and level distribution,etc. Simpson index and ShannonWeinner index of herb layer in restored grassland were higher than that of other communities with the highest Pielou index in bare land. The diversity indices of shrub layer and tree layer had the highest values in nondamaged forest. Based on the diversity indices, average height and average coverage of different layers, general diversity indices of communities were calculated and the highest value appeared in nondamaged forest, whereas the lowest in bare land. According to the results, the living condition of vegetation deteriorated due to secondary geohazards, so vegetation restoration would be improved by manual intervene to increase its species diversity and restoration potentials.