Agricultural expansion and the fate of global conservation priorities

Abstract

Non-governmental organizations have proposed nine different global prioritization schemes, some of them focusing on areas with low vulnerability (a proactive reasoning) and some others targeting areas with high vulnerability (a reactive reasoning). The main threat to the remaining natural habitats of these areas is the expansion of agriculture. We evaluated the spatial congruence between agricultural land cover and global conservation priority areas in the present and in the future using a spatial model of land use cover change from 2000 to 2100. We showed that by the year 2000, the extent of agriculture was larger in reactive priority areas than in the rest of the world, while it was smaller in areas highlighted as important under proactive approaches. During the twenty-first century, we found a general increase in agriculture area and the difference between the approaches of conservation schemes is expected to hold true, although we found that high-biodiversity wilderness areas (HBWA), a proactive scheme, may be specially affected in certain scenarios of future change. These results suggest an increase in conservation conflicts over this century. In face of agricultural expansion, both kinds of prioritization approaches are important, but different strategies of protection are necessary (e.g., reactive approaches need the urgent protection of remnant habitats, while proactive ones have space to create megareserves). Further, conservation organizations must include agriculture expansion data and their uncertainty in conservation planning in order to be more successful in biological conservation.