Investigation And Analysis Of Landslide Vegetation In Severely Damaged Areas After Wenchuan Earthquake

From2011to2013, we consecutively investigated the fixed-point places in the following counties:Haimianjiao protection zone in Jushui Town An County, Xuanlanggou Village in Mianyang City, Fengmaoping Village in Mao County, Bingli Village in Wenchuan County, Tangjiashan barrier lake in Beichuan County, Xiejiadianzi Village in Pengzhou City, Jiuding Mountain spot in Shifang City, Longchi spot in Dujiangyan City, Shuiguan Village in Pingwu County, Donghekou in Qingchuan County. Based on the statistical method of the vegetation community in quadrats, the damaged matrix is categorized according to the earthquake disaster types of plots and the topsoil structures of damaged matrix, the vegetation are respectively analyzed on variance. The results are as followings:1. The vertical structure of the plant communities in typical damaged matrix has mainly two layers:shrub layer and herb layer. The richness of herb is larger than shrub, the herb percentage in severely frangible areas is larger than that in mildly frangible areas;2.The community similarity of different damaged bodies is between grade2and grade3,its average CJ value is0.8lager than the control, and there is significant difference between damaged bodies and the control.It indicates that earthquake and its secondary disaster change the composition of communities and the damaged communities display higher similarity;3. The a species diversity of different damaged bodies are analyzed on variance analysis, the results show that, the values of Wenchuan County and Maoxian County are becoming less annually, the others are opposite. There is significant difference between the different damaged bodies, in Simpson index, Shannon index, and Pielou index. There is significant different between damaged bodies and the control in Shannon index.In summary, from2011to2013after Wenchuan earthquake, the landslide vegetation in damaged areas is in favourable recovery period (except for Wenchuan County and Maoxian County), the number of rhizome semi-woody and woody plant species is becoming larger gradually. The vegetation on landslide surface is in the mild transition farom herb to shrub. However, the composition of the community species varies from the control.