ABSTRACT
Many cases of invasion by nonnative plants arise in areas where the native ecology has been disturbed by natural or anthropogenic means (Gill and Williams 1996, Lake and Leishman 2004, Alston et al. 2006). Disturbances typically cause fluctuations in the available resources, especially light and nutrients. Davis et al. (2000) proposed the “fluctuating resource theory of invasibility” in which invading species are more successful where and when they do not encounter intense competition from native species for the available resources. After a disturbance, reduced competition and increased resource availability may result in a disequilibrium of resource supply and uptake that leads to higher susceptibility of the community to invasion. In other words, greater net availability of resources results in greater susceptibility to invasion (Davis and Pelsor 2001). Several studies support this theory by showing that invasion is facilitated by increases in the availability of water and nitrogen (Seabloom et al. 2003), as well as light (Matlack 1994, Panrendes and Jones 2000).
