Community-level assisted migration for climate-appropriate prairie restoration

Abstract

Climate change threatens the long-term survival of highly fragmented habitats such as North American tallgrass prairie. De novo plantings into former agricultural sites can contribute to efforts to conserve prairie biodiversity, but past planting practice (including our own) has focused on the use of local species and genotypes. Climate change makes this “local-only” practice obsolete because of rapidly shifting species' ranges. We propose that new prairie plantings incorporate assisted migration at the community level; all species and genotypes that are viable in the changed climate and potentially could reach the site in an unfragmented landscape should be considered for inclusion. Selecting and sourcing species for climate-appropriate restorations is possible with minimal additional cost or expertise. Based on best-available estimates of current and future climate, species richness of future prairie plantings at our Minnesota study site could be increased by over one-third (26 new species). Potential risks to such extensive use of assisted migration are offset by the drastic conservation challenge of highly fragmented communities under climate change.