How fast are we losing species anyway?

28 03 2011

© W. Laurance

I’ve indicated over the last few weeks on Twitter that a group of us were recently awarded funding from the Australian Centre for Ecological Synthesis and Analysis – ACEAS – (much like the US version of the same thing – NCEAS) to run a series of analytical workshops to estimate, with a little more precision and less bias than has been done previously, the extinction rates of today’s biota relative to deep-time extinctions.

So what’s the issue? The Earth’s impressive diversity of life has experienced at least five mass extinction events over geological time. Species’ extinctions have kept pace with evolution, with more than 99 % of all species that have ever existed now gone (Bradshaw & Brook 2009). Despite general consensus that biodiversity has entered the sixth mass extinction event because of human-driven degradation of the planet, estimated extinction rates remain highly imprecise (from 100s to 10000s times background rates). This arises partly because the total number of species is unknown for many groups, and most extinctions go unnoticed.

So how are we going to improve on our highly imprecise estimates? One way is to look at the species-area relationship (SAR), which to estimate extinction requires one to extrapolate back to the origin in taxon- and region-specific SARs (e.g., with a time series of deforestation, one can estimate how many species would have been lost if we know how species diversity changes in relation to habitat area). Read the rest of this entry »





International Congress for Conservation Biology 2010 overview

18 07 2010

A few posts ago I promised a brief overview of the 2010 International Congress for Conservation Biology (ICCB) that I attended last week in Edmonton, Canada. Here it is.

While acknowledging that it is impossible for any single individual to attend all talks at a congress of this size given that there were usually around 6-8 concurrent sessions on most days, I can provide only a synopsis of what I saw and what I heard from others.

I’ve been lukewarm about the two SCB conferences I have attended in previous years (Brasilia and Chattanooga), and I expected about this same this time around. However, overall the presentations were generally of a higher quality, the audio-visual was professional and the schedule was humane (I really, really, really like 09.00 starts; I really, really, really hate 08.00 starts).

For me, highlights certainly include Tyrone Hayes‘ plenary on the evils of atrazine, Fangliang He‘s description of the perils of overestimating extinction rates from species-area relationships, Mark Burgman‘s account of the crap performance of ‘experts’ in returning truth, Stuart Pimm‘s advocacy of scientific advocacy, Bastian Bomhard‘s sobering account of our failure to meet the 2010 Convention on Biological Diversity targets, Rob EwersBioFrag software, Tom Brook‘s account of vertebrate threat patterns, Rob Dietz‘ presentation on the Centre for Advancement of the Steady State Economy, Guy Pe’er‘s review of population viability analyses, and of course, the Conservation Leadership Programme salsa party! Read the rest of this entry »