You may remember my recent nibble on assisted migration. I also sent the link to the CropWildRelatives discussion group, which elicited this response from Nigel Maxted at the University of Birmingham:
This is indeed an interesting question. My first reaction was that it was a purely academic exercise that will do little to benefit overall biodiversity and probably could not be applied for a wide range of species even if this were economically and practically feasible. It might even do harm because government might use research like this to play down the impact of climate change and avoid the necessity of taking harsh economic decisions. This may well be the case, but for the key 500-700 globally important CWR I do think this is the sort of research we should enacting now. These critical 500-700 species will be so vital to future food security, not least to combating climate change itself, that we need to ensure that they are allowed to continue evolving in situ in the changing environment and make doubly sure we have these species’ genetic diversity adequately conserved ex situ. The research need not focus on the entire 500-700 CWR but could be passed through a modeled climate change impact filter first to identify those species most likely to be impacted in the short term and most likely to be successful in transposition. Perhaps as a community the time is right to systematically address this issue.
And this in from Prof. Vernon Heywood:
Assisted migration (McLachlan & al. 2006) or assisted colonization
(Hunter 2007; Hoegh-Guldberg), is a fairly drastic remedy and like
habitat restoration, a complex and potentially costly venture and
needs to be subject to careful cost-benefit analysis and perhaps used
only in exceptional circumstances. Moving species into new
environments is, as McLachlan & al. (2006) say, a contentious issue
and may involve considerable risks. It is a complex issue involving
not just scientific, technical and economic but sociological and
ethical considerations. It requires a sound and well thought out
policy framework before it is widely undertaken as a management
response to global change but might be prove to be appropriate in a
number of high priority species such as CWR of major crops.
Vernon
References:
Hunter, M.L. 2007. Climate change and moving species: furthering the
debate on assisted colonization. Conservation Biology 21: 1356–1358.
Hoegh-Guldberg, O., L. Hughes, McIntyre, S., Lindenmayer, D.B.,
Parmesan, C., Possingham, H.P. & Thomas, C. D. 2008. Assisted
Colonization and Rapid Climate Change. Science 321: 345 – 346.
McLachlan, J. S., J. J. Hellmann, and M. W. Schwartz. 2007. A
framework for debate of assisted migration in an era of climate
change. Conservation Biology 21: 297-302.
Thanks, Nigel and Vernon. This would indeed be a contentious, drastic and complicated business. I wonder if we could identify the highest priority candidate species: highly threatened (high altitude, coastline etc), relatively narrow endemic, close relatives of major crops, with a suitable recipient site(s). Then we could in a concrete way explore what would need to be done, and ways of overcoming the inevitable problems. It’s a little difficult to think about this in the abstract, as each species would be different. Any ideas?
Could there be a link to tourism? The Galapagos, for example, have an endemic cotton…
And from Suzanne Sharrock.
The topic of assisted migration is something that is also being discussed amongst the botanic garden community. It is obviously a complex subject – and something we don’t have any answers for at present. Just yesterday I attended a debate on the future of botanic gardens – and it was noted that botanic gardens have an important role to play in providing support (horticultural skills, plant materials, scientific expertise etc.) to efforts to conserve plant communities in the face of climate change. Given that the focus of botanic gardens is more specifically on conserving wild plants rather than crops – the issue of how wild plants can be conserved when their native habitats are no longer suitable for them is of great concern to botanic gardens. Assisted migration might work for some species – but again, this may not be appropriate in certain situations (old climatically-buffered infertile landscapes being cited as a case in point).
Assisted migration also raises the problem of invasive plants – how can we be sure we will not assist a plant to become invasive in its new habitat?
Anyway, just to say that this is a topic we are interested in – and we would be keen to be involved in future debate and practical actions to resolve some of the unknowns.
Suzanne
Each species is unique it is a major mistake to make them forcibly migrate to a different location. They might even die in the new location. Each species is genetically built to live in particular places if we disturb it we are probably going to loose it. I say we must take care of the problems that are affect the place that they live in at present.
And more from Nigel:
I agree with the various points made by contributors to the discussion thus far, but in response to your specific question – to do a thorough and appropriate job would require the funding of a grant application – who might fund such an international study? But from legume experience I can think of some obvious species to test
a. Vavilovia formosa (wild pea), found at about 10 sites in the Middle East all over 1800m always growing on limestone scree
b. Lathyrus belinensis (wild sweet pea), found at one site only on the Antalya coast of Turkey
c. Vicia hyaeniscyamus and V. kalakhensis found at about 7 and 3 sites respectively with basaltic soil on the Lebanon/Syria border
I am sure we could all come up suggestions for species to experiment with and as the Willis et al. paper and Vernon have pointed out there is a growing literature on the subject. I guess my point is I think we should also be experimenting with this ourselves in the PGR community for the most critical CWR species.
Changes in interdependence (i.e. between countries, departments, municipalities) should also be a guide to select not only species but also sites to which priority species could be shifted. Sites could be just a bit further or upper from actual zones where species are currently located.
Insects can migrate themselves (as in moths, for example); however, I guess that if we develop a model to select the most “useful” zone (nearby, most suitable, etc) for a particular plant species then we will be able to start testing to finally start the assisted migration process, won’t we?