California’s redwoods are some of the oldest and largest trees in the world, and their habitats near the coasts and the Sierra Nevada are rapidly changing. In recent years, climate change-driven drought and wildfires have rapidly threatened their existence. Now a small group of activists and scientists is hoping to save them via “assisted mitigation,” the process of planting new redwood trees in other places.
For some in the scientific community, it’s controversial to introduce new trees in an unfamiliar environment. But others argue the redwoods are too legendary to not try something.
Two methods are involved in moving these trees, explains Moises Velasquez-Manoff, who recently wrote about this for the New York Times Magazine. You take a cone to a nursery, place it in a pot and grow it, then plant the new seedlings elsewhere. Or you create a genetically similar or identical clone of the tree, sprout the cutting so it can grow new roots, then put it in a pot and plant it somewhere else.
One Washington state resident, Philip Stielstra, is on a mission to plant millions of redwoods — mainly from nurseries — in the Pacific Northwest.
“I don't think anyone has quite figured out what the limit is in the Northwest of where you can and cannot grow these … as long as you start them out with water until they get established, and then they have their own momentum after a while,” says Velasquez-Manoff.
He points out that both California redwood species are well-adapted to moderately intense fires. “The coast redwood has really thick bark that protects it from fires. And the giant sequoia actually requires fires of moderate intensity … for its cones to fall from high up and into the ground and in a way to complete its life cycle. The problem is fires have been getting so intense that they hop up into the crown of the tree and just end up burning all the foliage and killing these trees.”
Also, when mankind interferes with nature, moving species around, unintended consequences could happen. “It seems unlikely, although you can't say for sure ... that there would be this unleashing of a giant tree invasion in the Pacific Northwest.”
Still, repopulating and moving around redwoods could mean more carbon capture.
“The guy who's heading this effort under the name Propagation Nation (that's his nonprofit), his selling point is … the carbon capture ability of coast redwoods in particular because they are extremely resistant to rot. … When they’re old growth, scientists have done these measurements, they actually store more carbon than even the Amazon rainforest.”