Adaptation and gene flow are insufficient to rescue a montane plant under climate change.

Climate change increasingly drives local population dynamics, shifts geographic distributions, and threatens persistence. Gene flow and rapid adaptation could rescue declining populations yet are seldom integrated into forecasts. We modeled eco-evolutionary dynamics under preindustrial, contemporary, and projected climates using up to 9 years of fitness data from 102,272 transplants (115 source populations) of Boechera stricta in five common gardens. Climate change endangers locally adapted populations and reduces genotypic variation in long-term population growth rate, suggesting limited adaptive potential. Upslope migration could stabilize high-elevation populations and preserve low-elevation ecotypes, but unassisted gene flow modeled with genomic data is too spatially restricted. Species distribution models failed to capture current dynamics and likely overestimate persistence under intermediate emissions scenarios, highlighting the importance of modeling evolutionary processes. Editor's summary: Species stressed by climate change must move or adapt in order to persist. However, adaptation and gene flow between populations adapted to different climates are rarely integrated into models predicting how species will respond to climate change. Anderson et al. collected data on Boechera stricta, a common perennial plant, from five common garden experiments in the Rocky Mountains of the US to quantify the amount of migration needed to keep up with climate change and the potential for evolutionary rescue (see the Perspective by Aitken). Using integral projection models, they predicted a decline in adaptive potential and insufficient gene flow to keep up with climate change. This work shows the importance of accounting for evolution in ecological predictions and the limitations of species distribution models. —Bianca Lopez [ABSTRACT FROM AUTHOR]