Impact of excessive drought on regional sensitivity of Eupatorium adenophorum invasion in Yunnan province

It was exposed to excessive drought from winter in 2009 to spring in 2010 at Southwest China. Regional sensitive evaluation system of biological invasion was built up with indexes such as ratio of invasion area, diffusing distance, spreading manner and resistance of local biological community. And then the impact of excessive drought on regional sensitivity of Eupatorium adenophorum invasion in Yunnan province was analyzed. The research results indicated that the vigor of local aborigines was declined rapidly, and the resistance against biological invasion was sharply decreased according to the drought disaster. The normalized difference vegetation index (NDVI) at 1.19% of the province area in 2010 was overly decreased, and that of 49.19% strongly reduced compared with that in 2009. Then the conclusion was draw out that Dali, Dehong, Baoshan and the buffer area along rivers at Lincang, Puer, Yuxi and Honghe had been the most sensitive area to Eupatorium adenophorum invasion, and it should be spread broadly or break out after the drought disaster. And then the supervised advice was given out to keep from the biological invasion.