Conservation without frontiers

Protected areas are intended to mitigate pressures on biodiversity caused by anthropogenic factors such as habitat loss. To that end, an internationally agreed target aims to extend the protected area network to cover 17% of the world’s land area by 2020. But biodiversity is unevenly distributed between countries and habitats, raising the question of which areas should be protected to maximize the effectiveness. Federico Montesino Pouzols et al. show that internationally coordinated expansion of the protected area network to the 17% target could triple the average protection of species ranges and ecoregions. However, within-country prioritization is considerably less efficient. Moreover, taking into account projected land-use changes and consequent habitat loss until 2040, current levels of protection will not be feasible to maintain, and over 1,000 threatened species face reductions in their range of over 50%. Thus, the authors suggest that for effective biodiversity conservation, land-use policy and protected area decisions must be coordinated at an international level.