Assisted migration refers to the practice of facilitating the movement of populations of long-lived organisms, such as trees, across geographic areas from where the population currently exists to an area where the climate is likely to be suitable for the population in the future. Plant populations evolve over long time scales to adapt to changing conditions through the process of natural selection. However, due to the predicted pace of climate changes, and because trees take many years to reach reproductive age, there may be cases where naturally regenerated forests become maladapted to their site. Assisted migration methods may include planting genotypes from a different seed zone, introducing pollen from a different seed zone, or planting new species altogether. Assisted migration is still largely in the research and development stage. Assisted migration should be carefully thought out and should incorporate climate models, as well as site-specific information.
Suggested further reading: St. Clair, J.B. and Howe, G.T. Genetic Options for Adapting Forests to Climate Change. Western Forester, 54(1): 9-11, 2009.
Amy Grotta, Assistant Professor and Cooperative Extension Forester, Oregon State University
