Mapping threatened ecosystems in Australia

This is an interesting map, recently published as part of the Bioscience article 'The Spatial Distribution of Threats to Species in Australia', Evans et al., BioScience, 61(4):281-289. 2011.

Figure 3: The distribution of the predominant threats to biodiversity across Australia. The “predominant threat” is the threat affecting the greatest number of species in each subcatchment. Where two or more threats affect an equivalent number of species, we consider there to be no predominant threat occurring in these subcatchments, displayed here in shades of gray.
Darker colors indicate a larger overall number of threats occurring in the subcatchment. White indicates areas where no threatened species occur.

 This is quite a novel way to highlight the range of threats to Australian ecosystems, putting them in a spatial context.  The article argues that the use of such a spatial and visual analysis will aid mitigation efforts and help identify location-specific threats.

Mother Nature's Melting Pot?!

The latest 'pro-invasive' article I've come across was from reading this post on my colleague Shuang's blog, linking to an article in the New York Times "Mother Nature's Melting Pot".  This article makes a pretty outrageous link (imho) between alien plant and animal species and human immigrants.  Hang on, Homo sapiens are a single species last time I checked, so perhaps its not too surprising we can live happily alongside one another - though then again, perhaps we could take a few lessons from ecology in that respect!

While the vanguard of the anti-immigrant crusade is found among the likes of the Minutemen and the Tea Party, the native species movement is led by environmentalists, conservationists and gardeners. Despite cultural and political differences, both are motivated — in Margaret Thatcher’s infamous phrase — by the fear of being swamped by aliens.

April review for F1000

This month we have found some good papers.  We decided to first review a paper that is very much in Mark's field of interest - what factors determine species invasion success.  This paper provides some evidence as to whether greater phenotypic plasticity of invasives is important. 


 AM Davidson, M Jennions, AB Nicotra (2011) Do invasive species show higher phenotypic plasticity than native species and, if so, is it adaptive? A meta-analysis. Ecol Lett 2011 Apr 14 4:419-31
DOI 10.1111/j.1461-0248.2011.01596.x

Our Review: Parry H, Lonsdale M: 2011. F1000.com/9268957 
Another review of this paper is also available at the above link, by Hao Wang and Mark Lewis of the University of Alberta, Canada. 


What are the determinants of success in invasive species? Tonnes of wood pulp have been expended in proposing predictors of invasion success, such as morphology, taxonomic relatedness and propagule pressure, which might help us to screen out dangerous species before it is too late.

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.