Author: Y. Buckley
In a Nature article this week Davis et al. argue apparently we need to get over the “invasives are all bad & evil” mind-set. I’m broadly in agreement with the authors in that we’ve been saying for years now that focussing solely on the invader as a management objective is doomed to failure and instead we need to have conservation and restoration management objectives that specifically focus on what our true management goals are (Buckley 2008). Management of invaders may be part of the strategy for getting there but shouldn’t be the only reason for management.
It’s easy to see however, how articles like Davis et al. will stir up all kinds of back-lash. On Radio National this morning it was painted as a very black & white argument with one side being implied to have “given up” on invader management (Davis, Hobbs) and the other side staunchly defending the management of invaders (Mike Archer). Davis & Hobbs actually had a more nuanced argument that said that damaging invaders should be managed, but that we need to be pragmatic and focus our management efforts and dollars on invaders with proven impacts.
So where does this leave pre-border management? Management pre-border or in the very early stages of a potentially damaging invasion can be the most cost-effective action if it prevents serious damaging and unmanageable impacts later on (e.g. Yokomizo et al. 2009). We therefore need to get better at predicting what kinds of species will have the kinds of impacts we’re worried about on economic activities and on the natural environment. We are still a long way from that predictive science of impacts, especially in rapidly changing ecosystems. However our recent work has shown that non-native grassy and herbaceous plant species broadly maintain similar dominance hierarchies and abundances in both their native and non-native ranges (Firn et al. 2011). We should therefore be able to infer some aspects of how non-natives will function in their new ranges from observations in their native ranges.
Buckley, Y. 2008. The role of research for integrated management of invasive species, invaded landscapes and communities. Journal of Applied Ecology 45:397-402.
Firn, J., J. L. Moore, A. S. MacDougall, E. T. Borer, E. W. Seabloom, J. HilleRisLambers, W. S. Harpole, E. E. Cleland, C. S. Brown, J. M. H. Knops, S. M. Prober, D. A. Pyke, K. A. Farrell, J. D. Bakker, L. R. O’Halloran, P. B. Adler, S. L. Collins, C. M. D’Antonio, M. J. Crawley, E. M. Wolkovich, K. J. La Pierre, B. A. Melbourne, Y. Hautier, J. W. Morgan, A. D. B. Leakey, A. Kay, R. McCulley, K. F. Davies, C. J. Stevens, C.-J. Chu, K. D. Holl, J. A. Klein, P. A. Fay, N. Hagenah, K. P. Kirkman, and Y. M. Buckley. 2011. Abundance of introduced species at home predicts abundance away in herbaceous communities. Ecology Letters 14:274-281
Yokomizo, H., H. Possingham, M. Thomas, and Y. Buckley. 2009. Managing the impact of invasive species: the value of knowing the density-impact curve. Ecological Applications 19:376-386.