Oscar Venter 1 , 2 , * , Richard A. Fuller 2 , Daniel B. Segan 2 , 3 , Josie Carwardine 4 , Thomas Brooks 5 , 6 , 7 , Stuart H. M. Butchart 8 , Moreno Di Marco 9 , Takuya Iwamura 10 , Liana Joseph 2 , 3 , Damien O'Grady 11 , Hugh P. Possingham 2 , 12 , Carlo Rondinini 9 , Robert J. Smith 13 , Michelle Venter 1 , James E. M. Watson 3 , 14
24 June 2014
Meeting international targets for expanding protected areas could simultaneously contribute to species conservation, but only if the distribution of threatened species informs the future establishment of protected areas.
Governments have agreed to expand the global protected area network from 13% to 17% of the world's land surface by 2020 (Aichi target 11) and to prevent the further loss of known threatened species (Aichi target 12). These targets are interdependent, as protected areas can stem biodiversity loss when strategically located and effectively managed. However, the global protected area estate is currently biased toward locations that are cheap to protect and away from important areas for biodiversity. Here we use data on the distribution of protected areas and threatened terrestrial birds, mammals, and amphibians to assess current and possible future coverage of these species under the convention. We discover that 17% of the 4,118 threatened vertebrates are not found in a single protected area and that fully 85% are not adequately covered (i.e., to a level consistent with their likely persistence). Using systematic conservation planning, we show that expanding protected areas to reach 17% coverage by protecting the cheapest land, even if ecoregionally representative, would increase the number of threatened vertebrates covered by only 6%. However, the nonlinear relationship between the cost of acquiring land and species coverage means that fivefold more threatened vertebrates could be adequately covered for only 1.5 times the cost of the cheapest solution, if cost efficiency and threatened vertebrates are both incorporated into protected area decision making. These results are robust to known errors in the vertebrate range maps. The Convention on Biological Diversity targets may stimulate major expansion of the global protected area estate. If this expansion is to secure a future for imperiled species, new protected areas must be sited more strategically than is presently the case.
Under the Convention on Biological Diversity (CBD), governments have agreed to ambitious targets for expanding the global protected area network that could drive the greatest surge in new protected areas in history. They have also agreed to arrest the decline of known threatened species. However, existing protected areas perform poorly for coverage of threatened species, with only 15% of threatened vertebrates being adequately represented. Moreover, we find that if future protected area expansion continues in a business-as-usual fashion, threatened species coverage will increase only marginally. This is because low-cost priorities for meeting the CBD targets have little overlap with priorities for threatened species coverage. Here we propose a method for averting this outcome, by linking threatened species coverage to protected area expansion. Our analyses clearly demonstrate that considerable increases in protected area coverage of species could be achieved at minimal additional cost. Exploiting this opportunity will require directly linking the CBD targets on protected areas and threatened species, thereby formalizing the interdependence of these key commitments.