Abstract: The Asian elephants in Xishuangbanna,Yunnan have frequently walked out the nature reserves to massively destroy crops and seriously injure human and cattle in recent years.This may result from the nature reserves fragmentation and isolation of the distribution of bamboo and wild banana,which are the main resource of foodstuff.For Asian elephants,having no natural enemies and being well protected,the population has rapidly developed from 101 to about 250 since 1976.Nature reserves fragmentation and lack of foodstuff supply forced the Asian elephants to walk out of the nature reserves.By comparison,in the areas which are uncontrolled by elephants,with strong breeding capacity and fire tolerance,bamboo and wild banana have developed quickly and became dominant species in abandoned shifting cultivating lands and degraded ecosystems,causing great decrease of species diversity.The conservation strategy for Asian elephants has been discussed as well.

Key words: Qinling Mountains, Sharp tooth oak, Clustering analysis, PCA