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p-forum: Andrew Balmford, Leon Bennun, Ben ten Brink, David Cooper, Isabelle M. Côte, Peter Crane, Andrew Dobson, Nigel Dudley, Ian Dutton, Rhys E. Green, Richard D. Gregory, Jeremy Harrison, Elizabeth T. Kennedy, Claire Kremen, Nigel Leader-Williams, Thomas E. Lovejoy, Georgina Mace, Robert May, Phillipe Mayaux, Paul Morling, Joanna Phillips, Kent Redford, Taylor H. Ricketts, Jon Paul Rodríguez, M. Sanjayan, Peter J. Schei, Albert S. van Jaarsveld, and Bruno A. Walther ECOLOGY: The Convention on Biological Diversity's 2010 Target Science 2005; 307: 212-213 [Summary] [Full text] [PDF]

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Good news and bad news for the 2010 biodiversity target

Daniel P Faith, S. Ferrier, NSW Department of Environment and Conservation   (17 March 2005)

Good news and bad news for the 2010 biodiversity target 17 March 2005
Daniel P Faith, Research Scientist The Australian Museum, S. Ferrier, NSW Department of Environment and Conservation Respond to this E-Letter: Re: Good news and bad news for the 2010 biodiversity target	We sometimes wonder whether the best 2010 biodiversity target would be a “significant reduction” in the rate of production of new indicators. But we agree with Balmford et al. (Science, Policy Forum, 14 January 2005) on the need for additional biodiversity indicators for 2010 that better incorporate socio-economic factors. We have been exploring such indicators, based on the curves that track land-use changes in the “trade-offs” space of regional planning (1). Such trade-offs suggest some good news – and bad news – for the 2010 target of a significant reduction in the rate of loss of biodiversity. First, the down-side. A typical curve tracing loss of biodiversity (say, under some constant rate of habitat conversion to non-conservation, human-use, areas), shows that the rate of biodiversity loss generally will increase over time (3). Indeed, this “curse of the curve” means that even a reduced rate of habitat conversion could be accompanied by an increased rate of biodiversity loss (1, 2). Conventional indicators for 2010 based on rates of area change therefore may not indicate much. Now, the up-side. These same properties of curves suggest ways to make measurable progess towards the 2010 target – and, sensibly, credit the reductions in the rate of biodiversity loss that could arise from adoption of conservation strategies providing good trade-offs and synergies with other needs of society (1, 2). For example, adopting systematic conservation planning (4) could limit the overlap of new human-use areas with the areas most needed for biodiversity conservation, and so shift the region to a new curve with a lower rate of biodiversity loss (3). Thus, one positive indicator for 2010 could credit any new take-up of strategies providing effective regional trade-offs/synergies. More detailed indicators will need to overcome awkward aspects of these curves. For example, the rate of biodiversity loss still increases over time even for the best-possible curve (3). Any such curve, made possible by a strategy implemented now, arguably has to represent sufficient improvement so that the lower rate of loss has not totally disappeared by 2010. Ironically, it might be easier to record a reduced rate in 2010 if the new strategy was not implemented too soon! Equally disconcerting are curves where we can obtain a (fleeting) reduction in rate of loss in 2010 simply by converting lots of high-biodiversity-value land now. These considerations suggest that we need to evaluate the longer term gains from any strategy, to avoid artifacts from any “snapshot” taken in 2010. References and Notes D. P. Faith, Global Environmental Change 15, 5-8 (2005). J. McNeely et al., in Responses Assessment, Vol. 13 (Millennium Ecosystem Assessment Series, Island Press, Washington DC, in press). view 2010 trade-offs figure. This figure shows two land-use change curves for Panama (for background and related analyses of these data, see (5)). Both curves illustrate how a constant rate of habitat loss (horizontal axis) would imply an increasing rate of biodiversity loss (vertical axis). The lower curve is for a case where the choice of places for conversion is not balanced with conservation needs, and disproportionately targets certain habitat types. The upper curve is for a case where new human-use lands are selected so as to minimize conflict with regional biodiversity conservation. C. R. Margules, R. L. Pressey, Nature 405, 243–253 (2000). D. P. Faith, et al., Journal of Biogeography 31, 1207-1217 (2004).