Forest assisted migration under uncertainty

Problem: Should we use seeds from warmer locations to adapt forests to climate change ? We define assisted migration as the project to translocate populations to compensate for observed or future climate changes. It is justified since the pace of climate change is too rapid for most populations to track changing climates. The idea of assisted migration questions the current paradigm in forestry management, which is that local provenances are always the best first choice. The cases of Oak and Pine populations in France illustrate the timeliness but also the dangers of this idea.Method: A decision-making framework based on imprecises probabilities and multiple worldviews is used, which accounts for rationality and precaution. We represent the deep uncertainty on climate change by using worldviews on long term climate change based on simulations of 3 RCP scenarios and 3 climate models.Data: Experimental data from the British Columbia Ministry of Forests and Range's lodgepole pine provenance test, which consists of 140 populations tested at 62 sites, were used. An incomplete testing design tested 60 of the 140 populations at each site, so that each population was tested at 30–40 sites. Total height was measured at 43 of the 62 sites in autumn 2005, after 32 field growing seasons (35 growing seasons from seed).Conclusions: We find that assisted migration is already a policy issue. Our work illustrates a decision making criteria that is both rational and precautionary, by focusing on trades between two options instead of focusing on a choice considering each option in isolation . Canadian data was much easier to access and use than French. Early results points that assisted migration could be considered in higher latitute stations.Early results for assisted migration in higher latitude stations