A mediocre month

Well, the last couple of months have been a bit of a disappointment really, I've not come across anything to get excited about in the literature.  Thats not to say Ive not come across anything, but what Ive found hasn't exactly knocked my socks off or has left me very disappointed.  Some articles I have picked up thinking they are full of promise, only to find that the data they use is really quite shaky on closer examination, or their findings are not really too far beyond common sense.  These are some that I considered...


Stigall AL (2010) Invasive Species and Biodiversity Crises: Testing the Link in the Late Devonian. PLoS ONE 5(12): e15584. doi:10.1371/journal.pone.0015584

This article reaches the intriguing conclusion that lower vicariant speciation due to species invasions was responsible for the late Devonian 'biodiversity crisis'.  However, I was left wondering exactly how Dr Stigall worked out that there was an increase in invasion in the late Devonian resulting in prolific invasive species.  The only explanation made is based on the work of other authors, who infer that the evidence of the reduction in endemism during that period is indicative of increased interbasinal species invasions at that time (p2).  As this underpins the study to some extent I wasn't happy enough with that explanation to review it fully, although her argument was persuasive enough to prompt a review in Science Daily 'Invasive Species Stop New Life'...!


Another study that seemed initially quite promising was Essl F. et al. (2011) Socioeconomic legacy yields an invasion debt vol. 108, no. 1, 203-207


However, the conclusion to this article really seems somewhat obvious, unless I'm missing something?: 'current patterns of alien-species richness may better reflect historical rather than contemporary human activities', well, these things do take a little time!  I wasn't very satisfied with the discussion, I would have liked the article to consider more how historic activities relate to contemporary activities, including impacts of defense and mitigation, instead of making the somewhat simplistic conclusion that more stringent protection measures are imperative.

Finally, I have to mention the New Scientist article 'Aliens to the Rescue' , which is a very provocative article that sent quite a ripple through the community of Invasion Ecologists.  Using somewhat sensationalist language to fight the corner for the aliens, Garry Hamilton argues that aliens 'may be our last line of defence against ecological destruction'!  Statements such as 'there has been a big emphasis on looking at the negative side of the ledger' seem to indicate that the considerable damage done by many invasive species is nothing compared to the good some of them might do.  Perhaps some of the impact of the article is in the terminology.  Hamilton refers to invasives as perhaps being the good guys - when really he should perhaps have termed them 'non-natives', 'invasives' by definition implies that the species is destructive and so arguing that we should not be concerned about them simply makes no sense. Though on the whole the article seems really not very well informed and frivilous, for example the argument on page 36 that the elimination of alien feral cats on Macquarie Island was a bad thing as it led to an explosion of the rabbit population... but, hang on, rabbits are also an alien pest!  Unfortunately, I feel this is a bad example of (somewhat irresponsible) tabloid science, with little awareness of how invasive species are carefully and extensively studied and managed - 'indiscriminate eradication' just doesn't happen.