Zavaleta, ES; Hobbs, RJ; Mooney, HA. 2001. Viewing invasive species removal in a whole-ecosystem context. TRENDS IN ECOLOGY & EVOLUTION 16 (8): 454-459.
The authors discuss the importance of considering the potential secondary effects of invasive species eradication efforts in ecosystems where multiple invaders interact or where exotics have eliminated native species and replaced their functional roles. These secondary effects are particularly likely when efforts are focused on non-island ecosystems. The paper goes on to describe a valuable conceptual framework for evaluating the risk of unintended secondary effects. Yet, something is missing—while the authors acknowledge that global change is altering systems, their framework does not include this temporal challenge. Instead, they focus on species interactions & current ecosystem functions. Adding climate change’s temporal impacts to this framework requires one not just to evaluate short-term secondary effects, but also to assess whether climate conditions will continue to support the ecosystem restoration being attempted. In other words, if one manages to eradicate an invasive without unintended consequences, is that ecosystem likely to be more resilient than it would have been had we not attempted the eradication at all? The authors note a dearth of data in existing literature on the long-term performance of ecosystems in which “successful” invasive extirpations have occurred—a major challenge for planners.
Photo Credit, Lori Oberhofer, National Park Service.