Decision Support Project Bp-2

Crop wild relatives are an important source of genetic diversity for crop improvement. However, the survival of some of these wild plant species could be threatened because of climate change. We used current and projected future climate data for ~2055, and a climate-envelope species-distribution model to predict the impact of climate change on the wild relatives of peanut (Arachis), potato (Solanum) and cowpea (Vigna). We considered three migrational scenarios for modeling the range shifts (unlimited, limited, and no migration). Climate change strongly affected all taxa, with an estimated 16-22% of these species predicted to go extinct and most species losing over 50% of their range size. Moreover, for many species, the suitable areas become highly fragmented. Wild peanuts were the most affected group, with 24 to 31 (depending on the migration scenario) of 51 species projected to become extinct and their distribution area reduced by 85 to 94% over the next 50 years. The number of suitable areas changed by -19% to +4% and patch size decreased by 55 to 60%. For potato, 7 to 13 of 108 species were predicted to go extinct, and their range sizes were reduced by approximately 38 to 69%. The number of patches changed by -34% to 7% and patch size decreased by 20 to 37%. In terms of species extinction, Vigna was the least affected of the three groups, losing 0-2 of 48 species. The mean range size changed by -65% to 8%, with 8-41 of the 48 species losing more than 50% of their current geographic range. The number of Vigna patches increased by 12-115%, but the size of those patches shrank by 51-59%. Our results suggest that there is an urgent need to identify and conserve effectively crop wild relatives that are at risk from climate change. While increased habitat conservation will be important to conserve most species, those that are predicted to undergo strong range-size reductions should be a priority for collection and inclusion in genebanks.