为了解汶川地震灾区典型区域不同受损阶段群落特征,采用野外调查和室内分析相结合的方法,研究了北川县苏保河和魏家沟流域4种植被类型(灾后恢复草地、受损林地、裸地、未受损林地)群落种类组成、垂直结构、多样性等特征。结果表明:不同受损阶段群落在物种组成、物种数量、群落分层等方面差异显著;灾后恢复草地草本层Simpson指数和Shannon-Wienner指数最大,Pielou均匀度指数则以裸地最大;灌木层及乔木层多样性指数均以未受损林地最大;总体多样性指数则表现为未受损林地〉受损林地〉灾后恢复草地〉裸地。基于以上分析结果,本文得出地震灾区植物生长条件严重衰退,在植被恢复过程中应采用人工辅助方式,增大其物种多样性及恢复潜力。
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