Overview

• Assisted migration, a climate adaptation strategy, is being increasingly adopted in the Pacific Northwest to help native trees adapt to climate change.
• There are three forms of assisted migration: assisted population migration, assisted species migration, and range expansion.
• Assisted population migration, which involves moving a native species' seeds within its current growing range, is currently the only form practiced nationwide by the U.S. Forest Service due to its fewer ecological risks.
• Assisted species migration, which involves moving a species well outside its existing range, is seen as risky due to potential disruptions to the ecosystem, such as native caterpillars not eating the leaves of migrated nonnative tree species.
• Despite the risks, assisted migration is being increasingly adopted by public and private groups in the Pacific Northwest due to the growing effects of climate change.