Viewing invasive species removal in a whole-ecosystem context.

Zavaleta, Erika S., Richard J. Hobbs, and Harold A. Mooney. 2001. Viewing invasive species removal in a whole-ecosystem context. Trends in Ecology & Evolution 16 (8) (8/1): 454-9.

One of the main points of this paper is that many eradication efforts have unintended effects, even when they are successful in removing an invasive species. Another invasive species may then become more of a problem, or a native species may have come to depend on that invasive species. They suggest applying food web ideas to invaded systems, including concepts of trophic cascades and predator-prey/herbivore-plant interactions, and then give many clear examples of situations in which eradicating an exotic may have unintended negative consequences for native species and even to ecosystem functions. I admit that this seems obvious to me; why wouldn't you apply ecological theories like this to an invaded system to understand better what the consequences of potential restoration plans might be? But that seems to be one of the lessons of this class: we need better communication between scientists and planners/managers (also this paper is from 2001, and is highly cited, so that's a good sign). One thing I like about this paper is that again we do a little thinking about animals as well as plants and I believe that complements all the plant community ecology in the core papers. It's clearly written and presents a number of concrete examples of applications of the theories to invaded systems. I would be really curious to hear whether this approach of evaluating potential eradication plans has actually been adopted on the ground since the paper came out in 2001. Shortcomings of the paper include an emphasis on eradication as a method for restoration (how often is this really the strategy of choice, and when is it even practical other than on islands?) and a call for more monitoring and pre-evaluation but of course no suggestions for how to make this practicable.