False economy in degazetting protected areas

Fuller et al (2010) claim that 'replacing underperforming protected areas achieves better conservation outcomes'. Their strategy is to ‘reverse the protection status of the least cost-effective sites’, But this approach may not be effective at identifying opportunities for new cost-effective protected area networks.

False economy?

We applaud the fact that Fuller et al. address the issue of inefficiency of existing protected areas (PA) networks, suggesting that protected areas expansion could do well if it moved away from considering existing PAs as fixed. In our own conservation planning work in Papua New Guinea (Faith et al., 2001; Pacific Conservation Biology) we found that, when we did not regard existing PAs as fixed, we could achieve our biodiversity representation goals at nearly 25% less cost.

But we anticipate problems in selling the idea of de-gazetting PAs to achieve supposed greater efficiency. We all would probably agree that, unless all the relevant costs and constraints are on the table, these ‘efficiency’ analyses are largely academic exercises. That is a concern particularly with regard to finding effective measures of biodiversity (as in our PNG study). Fuller et al. use percent targets, which have some well-known weaknesses (most recently highlighted at a pre-COP meeting). Without good information on biodiversity, these cost-effectiveness approaches can only efficiently pursue an inefficient solution. Surely, this provides no strong case for de-gazetting - there would be little reason to be confidant that the new PAs actually captured more biodiversity.

But even if we had a good list of all species and good cost estimates, Fuller et als proposed method does not provide a strong case for de-gazetting, because their method is not an effective way to find efficient solutions. Their suggested ‘radical approach’ is to ‘reverse the protection status of the least cost-effective sites’, and use that capital for new PAs. But that approach does not in general identify the set for de-gazetting that would result in greatest efficiency. The best set of PAs to remove depends on what is available for selection as new PAs. They ignore this.

Suppose we have the following 5 existing protected areas (perhaps part of a larger set), with species designated by letters, followed by cost of the area. Species a through f are unique to these listed PAs.

1. [ab] 10

2. [cd] 10

3. [ef] 10

4. [lmno] 15

5. [pqrs] 15

Outside the PAs, 7 species, t through z, are not represented in any PAs, but are available in one or more other areas, for a total cost of 30 units. Many copies of species l through s are available in these same areas. De-gazetting ‘the least cost-effective sites´ implies removal of areas 1, 2, and 3. Each has a complementary benefit of 2 species and cost of 10 units. Spending the released capital of 30 units on new areas then picks up 7 new species, t through z, for a total biodiversity score in the new PA set of 15 (species l through z).

The alternative approach (in the planning tools used in PNG and elsewhere) would recognise areas 4 and 5 as the best to remove, so that spending the same 30 units now means that new areas can pick up 7 new species, t through z, and replace l through s cheaply. Plus, we have retained species a through f, for a total of 21 (species a through f; l through z). Efficiency is greater.

The Fig 7a example in Faith (1995) Biodiversity and Regional Sustainability Analysis  illustrates this kind of problem, in a trade-offs space. A set of protected areas (hollow square) allocated without looking at what might be added to that protected set constrains all possible additions to the set to result in solutions falling along a curve with relatively poor efficiency.

Fuller et al.'s proposed strategy to ‘reverse the protection status of the least cost-effective sites’ perhaps could be modified to ‘reverse the protection status of that set of sites that best takes advantage of properties of available new PAs’. But, even with that improvement, de-gazetting will be a hard sell, given all the other factors that inevitably do not make it into these supposed ‘efficiency’ calculations.

Dan Faith, the Australian Museum
Kristen Williams, CSIRO
A modified version of this essay, along with the Fuller et al paper, can be found at Comments at nature.com

References

Faith D.P. (1995) Biodiversity and regional sustainability analysis. CSIRO, Canberra. ISBN 0 643 05764 1

Faith D.P., C.R. Margules and P.A. Walker. (2001) A biodiversity conservation plan for Papua New Guinea based on biodiversity trade-offs analysis. Pacific Conservation Biology. 6. (4): 304-324

Fuller et al (2010) Replacing underperforming protected areas achieves better conservation outcomes. Nature
doi:10.1038/nature09180


Dr Dan Faith , Principal Research Scientist
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