Scientists Help Trees Migrate North to Survive Climate Change

Trees migrate just like animals do, but they move so slowly that climate change is leaving them behind.

When temperatures shift, tree species naturally expand into new territories through wind and animal-dispersed seeds. But here's the problem: climate change is happening at least 10 times faster than trees can naturally move, which historically was only 12 to 25 miles per century.

Scientists across the United States are now giving trees the boost they need. They're collecting seeds from locations that will soon become too warm and planting them in cooler regions farther north where conditions will be ideal in the coming decades.

Katie Nigro, a postdoctoral fellow with the Oak Ridge Institute for Science and Education, explains that a Douglas fir thriving in Colorado today might struggle there in 30 years. But planted farther north now, it could flourish for centuries.

The challenge is unique because trees live such long lives. "Trees live a long time and take a long time to get to reproductive age," says Mike Battaglia, a research forester at the USDA's Rocky Mountain Research Station. Unlike faster-growing species, trees don't get many chances to naturally adapt through evolution.

Researchers use climate models to predict future temperatures, humidity, and wildfire patterns for specific locations. They then match those conditions with tree seeds already adapted to similar climates elsewhere, sometimes selecting different populations within the same species.

The work happens primarily during reforestation efforts after wildfires, disease outbreaks, or logging. Robert Slesak from the Pacific Northwest Research Station says it makes practical sense to plant climate-adapted seedlings when replanting is already underway.

The Bright Side

The Experimental Network for Assisted Migration and Establishment Silviculture is already implementing this strategy across multiple research stations. While the approach carries some risks, like potentially introducing pests or unsuitable genetics, researchers emphasize there's also a risk in doing nothing.

Recent projects have even moved California's coastal redwoods and giant sequoias to Washington state, potentially saving these iconic species from extinction as their limited range shrinks. The strategy considers not just temperature but also factors like reduced mountain snowpack, drier summers, and more frequent fires.

Forests cover vast amounts of land, but only a small fraction gets replanted each year. "It's kind of a no-brainer to just at least do what you can on the ground," Slesak says, and that practical optimism is helping secure forests for future generations.