Plant Community Resistance To The Invasion Of Eupatorium Adenophorum In Southwest China

As an important component of global change, biological invasions have evoked increasing attentions and community invasibility is one of its core and hottest issues. Croftonweed is a troublesome invasive weed native to Mexico and has spread rapidly across southwest China. First, the plant communities invaded by croftonweed in southwest China were classified. Second, we discussed the effects of topographical factors, native plant diversity and environment gradients on the resistance of plant communities to the invader. Finally, we simulated and predicted the spatial distribution pattern of this invasive plant. At the small scale, invasion success of croftonweed was negatively correlated with native plant diversity indicating that resource availability might be the dominant factor regulating community invasibility at this scale. In addition, native plant diversity also inhibited croftonweed over the course of community succession and at the early stages of invasion. At the large scale, variations in physical environment outweighed the importance of intrinsic biotic factors and positive relationships between diversity and invader success were found. Roads and streams were the major conduits for the spread of croftonweed in southwest China. Resources availability was the dominant factor for the invasion resistance of communities along roads and streams. The abundance centers of croftonweed were Cangyuan, Yuanjiang and Xichang; Leye, Chongqing and Luding, which were at the edge of its range, would shape new centers, composing propagule pressure on the regions north and east to them. At present, the range of this invasive plant in China was mainly located on the Yunnan and Guizhou Plateau and the prediction indicated that this region would also be the core area of its potential distribution.