
The world’s boreal forests have been largely earthworm-free since the last Ice Age. But as invaders arrive and burrow into the leaf litter, they free up carbon and may accelerate climate change. Cristina Gonzalez Sevilleja
In my daily scan for information related to the environment, I invariably learn something that surprises me. Like the fact that the earthworm, which provide valuable ecosystem services, can also represent danger on a global scale:
‘Earthworm Dilemma’ Has Climate Scientists Racing to Keep Up
Worms are wriggling into Earth’s northernmost forests, creating major unknowns for climate-change models.
Earthworms recently have spread to Alaska’s boreal forest. In some areas, the biomass of earthworms is 500 times greater than that of moose, a keystone species. Lance King/Getty Images
Cindy Shaw, a carbon-research scientist with the Canadian Forest Service, studies the boreal forest — the world’s most northerly forest, which circles the top of the globe like a ring of hair around a balding head.
A few years ago, while conducting a study in northern Alberta to see how the forest floor was recovering after oil and gas activity, she saw something she had never seen there before: earthworms.
“I was amazed,” she said. “At the very first plot, there was a lot of evidence of earthworm activity.”
Native earthworms disappeared from most of northern North America 10,000 years ago, during the ice age. Now invasive earthworm species from southern Europe — survivors of that frozen epoch, and introduced to this continent by European settlers centuries ago — are making their way through northern forests, their spread hastened by roads, timber and petroleum activity, tire treads, boats, anglers and even gardeners. Continue reading






















Intelligence Squared has an app that allows you to listen to their debates and lectures at your own convenience, on your phone or wherever, whenever you choose. If, like us, you have found the rewilding debate interesting, this is one you will want to listen to:











