We may not know the exact sum figures of biodiversity, nor the precise percentages of species decline. It may also be irrelevant. Although ecology is in fact all about counting – we have to become aware that we are loosing something we don’t yet realize we value, at rates we may never be able to count.

It’s a magazine for scientific publications, like Science or Nature, but even when you say ‘Philosophical Transactions of the Royal Society of London’ you’re not fully done. You still have to distinguish between ‘A: Mathematical, Physical and Engineering Sciences’ and ‘B: Biological Sciences’. If you’d opt for the latter – and open their new special edition – you would find another interesting publication on biodiversity – one of many, as the UN process has a climax this week, with government delegates joining in on the big conference of the United Nations Convention on Biological Diversity, that is being held in Nagayo, Japan and has its final day tomorrow.

The Royal Society publication bundles 16 different studies – and then add their philosophical touch: “Ecology is in essence a quantitative discipline. It is underpinned by careful observations of the natural world, revealing for example that insect species richness is higher in tropical habitats than in temperate ones (Bates 1863), and that ecological communities invariably have a few common and many rare species (Darwin 1859),” the publication starts.

The authors however reach the conclusion that Earth’s biodiversity record is still very much incomplete. And although quantitative tools are indeed needed to better understand large-scale changes, the scientists also point to the fact that we need to accept the severity of these changes, even when exact numbers may be lacking.

This is not to say ecologists aren’t trying hard to come up with good estimates of biodiversity and the actual threat to species. The IUCN just did its bit with a study on vertebrates. The Global Census of Marine Life was published earlier this month, preceded by a threat analysis on plant life.

They all reach the same two conclusions: the quantity of total biodiversity is magnificent. And The Sixth Mass Extinction, the Holocene Extinction, is on.

The Royal Society scientists raise a few specific concerns with respect to the quantitative analyses: if you burn down tropical forests, but later allow a (secondary) forest to re-grow, “how many species would be able to re-colonize”?

Oceans form another obscure territory. “Fisheries in some areas are expected to collapse in response to repeated acute disturbance and increasing temperature,” a special sub-paper says. Ecologists however have no exact precedent to this warming. Which species may be able to adapt and which ecosystems will be hit beyond a possible recovery, is simply hard to predict. All we know is shellfish don’t like acidulous oceans [and coral, crustaceans, plankton, fish – come to say, any organism that depends on the formation of calcium carbonates, whether skeleton or shell-forming].

Want more considerations about the importance of biodiversity? Listen (podcast) to UNEP chief Achim Steiner – “Sometimes we have to get back to an intuitive understanding. When we talk about biodiversity we talk about life on Earth – it is as simple and complex as that” – on BBC One Planet today – or read our attempt to ethically define biodiversity.

© Rolf Schuttenhelm | www.bitsofscience.org