March Review for F1000

 This month we found something addressing the ongoing debate about the relationship between invasibility and diversity of native species; however, this study takes a new angle and looks at the relationship through time rather than across space.  Our biggest disappointment with this paper was that it makes a large assumption that abundance of a single species = diversity, which is not necessarily the case.  Therefore to really prove the conclusions of this study about this general hypothesis, the authors need to either test this assumption thoroughly or undertake a study focusing directly on invasive species diversity in relation to native diversity. 

Our Review:
Parry H, Lonsdale M: 2011. F1000.com/9274956 

This is the first study of note that attempts to examine the relationship between invasibility and native species diversity across temporal scales. The diversity-invasibility relationship has intrigued researchers interested in invasion ecology because a paradox has arisen, as the relationship appears to flip at different spatial scales.

Embracing Invasives

Embracing Invasives is the title of a recent article in Science.  So, it seems the pro-invasive band-wagon is growing!  In this article, Science take the case of the Galapagos - viewed by many as the world's most pristine environment - and highlight that scientists trying to eradicate invasives on these islands are now admitting defeat, ready to 'embrace' the presence of alien species.  Given the damage invasives such as Guava and Blackberries are known to do to this environment, I do wonder what the real reasons might be for giving up the fight? I think there is more to this story than given in this article.  Maybe I am cynical, but I would suspect budget cuts from struggling world economies that support such initiatives are to blame, rather than a scientific turnaround, which they are now trying to justify.  I'm afraid I am yet to be convinced that unquestioningly 'embracing invasives' is a well thought-out strategy, in the Galapagos or anywhere.  Not enough research has been done to really understand what the implications of allowing non-natives free-reign might be and until that is the case in a region then it would seem best to err on the side of caution.  However, I am getting an increasing feeling that there is a growing movement that suggests we err the other way - to allow non-natives free-reign until proven guilty.  I tend to think this is driven by economics and the needs of growing human populations, rather than science.  Without doubt, there is mounting and explosive controversy as general philosophy and practice in this area is undergoing dramatic changes at this time.

 Blackberries: Overwhelming ecosystems in the Galapagos.  Also a big problem in Australia.

New commission to address threats to food security from Climate Change

A New commission to address threats to food security from Climate Change has been set up in the UK, to look at Global food security issues.  "Chaired by the United Kingdom's Chief Scientific Adviser, Professor Sir John Beddington, the Commission will in the next ten months seek to build international consensus on a clear set of policy actions to help global agriculture adapt to climate change, achieve food security and reduce poverty and greenhouse gas emissions."

Looking on the bright side

There seems to be a recent trend in articles looking on the bright side of introduced species.  In my previous post I linked to the controversial New Scientist article 'Aliens to the rescue', which puts forward the case that there are "Friendly Invaders" and "Alien Species Save Ecosystems".  Another article along similar lines, although without the tabloid phrasing, has now appeared in Conservation Biology:


SCHLAEPFER, M. A., SAX, D. F. and OLDEN, J. D. , The Potential Conservation Value of Non-Native Species. Conservation Biology, EARLY VIEW doi: 10.1111/j.1523-1739.2010.01646.x

Such papers seem to me to be putting forward the 'pros' of introduced species as if the idea that non-natives have benefits is a new thing - but haven't we been growing 'non-native' wheat across the world for thousands of years, introducing bees for pollination etc etc?  This article frustrated me as the way it was conducted reviewed mainly only the positive effects of non-native species, not balancing their examples with negatives.  They do point this out, justifying it by saying such negative cases have been presented elsewhere, but really perhaps they should have put their examples  into context with some balance rather than simply leaning so far to the 'pro-non-native' camp that seems to be emerging.   Perhaps these articles are simply looking for citations, to say 'there are some good things about non-natives, quote...', or maybe academics are setting themselves up a Straw Man - making themselves an easier target to shoot down, by taking the pro- non-native argument to extremes.