May 31, 2010

Global biodiversity: (biased) indicators of recent declines

Stuart H. M. Butchart and coauthors write in Science (Global biodiversity: indicators of recent declines):
Only three indicators address trends in the benefits humans derive from biodiversity (Fig. 1 and Table 1): (i) population trends of utilized vertebrates have declined by 15% since 1970, and aggregate species’ extinction risk has increased at an accelerating rate (as shown by the Red List Index) for (ii) mammals, birds, and amphibian species used for food and medicine (with 23 to 36% of such species threatened with extinction) and (iii) birds that are internationally traded (principally for the pet trade; 8% threatened). Trends are not yet available for plants and other important utilized animal groups. Three other indicators, which lack trend data, show (iv) 21% of domesticated animal breeds are at risk of extinction (and 9% are already extinct); (v) languages spoken by fewer than 1000 people (22% of the current 6900 languages) have lost speakers over the past 40 years and are in danger of disappearing within this century (loss of linguistic diversity being a proxy for loss of indigenous biodiversity knowledge); and (vi) more than 100 million poor people [suffering from undernourishment] live in remote areas within threatened ecoregions and are therefore likely to be particularly dependent upon biodiversity and the ecosystem services it provides.
This is all they have to say about indicators of the benefits humans derive from biodiversity, and it is biased. They do not mention that we now have the highest ever (iv) rate of production of new animal breeds, (v) rate of production of biodiversity knowledge, as measured, for example, by the number of scientific publications, and (vi) number of people (more than 6.5 billion) who are "not particularly dependent upon biodiversity and the ecosystem services it provides." They also fail to mention that food supply per capita and the number and proportion of well-nourished people have steadily increased since 1970.

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