We recently published a paper in Nature showing how it is possible to dramatically improve the performance of protected area systems by replacing a small number of poorly performing sites with more cost-effective ones. This benefit to conservation is delivered without spending a single extra dollar.

Protected areas are one of the most important tools in modern nature conservation, with over 100,000 sites covering about 12 per cent of the land and territorial waters of countries worldwide. Enormous efficiency gains could be achieved by modest and careful adjustments to a protected area system. A more flexible approach to the expansion of a protected area system could ultimately protect much more biodiversity.

The contribution of Australian protected areas to conserving vegetation types relative to their rarity (B) is positively related to the estimated cost of acquisition and management of the sites (C). However, there is a great deal of scatter in cost-effectiveness among the 6,990 protected areas; here the least cost-effective 1% of sites (70 protected areas) are denoted by crosses.

Our modelling has shown that replacing the least cost-effective 1 per cent of Australia’s 6990 strictly protected areas could triple the number of vegetation types that are adequately protected. This huge benefit occurs because of the enormous variation in cost-effectiveness among existing sites. The figure on the left shows that some sites are delivering very little biodiversity protection given the level of investment needed to purchase the land.

The paper has sparked controversy because many conservationists view protected areas as sacred sites that shoud be protected in perpetuity. However, the reality is that many protected areas are in the wrong places, regions not needed for agricultural or urban expansion. Some of our reserves simply aren’t making the best use of this expensive form of conservation to protect our key natural values.

We can do much better if we reverse the protection status of the least cost-effective sites and use the resulting capital to establish and manage new protected areas. The rate of investment in new protected areas has slowed globally in recent years. Ensuring that the best places are protected is now more important than ever.

Fuller, R.A., McDonald-Madden, E., Wilson, K.A., Carwardine, J., Grantham, H.S., Watson, J.E.M., Klein, C.J., Green, D.C. & Possingham, H.P. 2010. Replacing underperforming protected areas achieves better conservation outcomes. Nature, 466, 365-367.

Link to the paper: http://dx.doi.org/10.1038/nature09180

Link to a commentary on the paper by Peter Kareiva: http://dx.doi.org/10.1038/466322a