Invasive Plants Versus Their New and Old Neighbors: A Mechanism for Exotic Invasion

• DOI: 10.1126/science.290.5491.521
• Publication Date: 2002-07-27T09:47:44Z
• Authors: Ragan M. Callaway; Erik T. Aschehoug
• Keywords: Centaurea; Noxious weed; Native plant

Invading exotic plants are thought to succeed primarily because they have escaped their natural enemies, not of novel interactions with new neighbors. However, we find that Centaurea diffusa , a noxious weed in North America, has much stronger negative effects on grass species from America than closely related communities which is native. 's advantage against American appears be due differences the its root exudates and how these affect competition for resources. Our results may help explain why some so successfully invade plant communities.