The greening of the arctic tundra

On the north slope of Alaska’s Brooks Range, Isla Myers-Smith knelt in the green vegetation of recently thawed land. She had just laid eyes on the treeless arctic tundra for the first time earlier in the day. Until then, his life had been defined by the trees. She was a master’s student in Fairbanks studying the impacts of wildfires on climate change. Before that, she grew up in Vancouver, British Columbia, among the huge trees of the coastal rainforest. But sitting there on the ground, clutching the leaves of a shrub that even then was visibly reacting to climate change, an idea took root in her mind that the open tundra landscape was where the work might be. of his life.

That day was almost twenty years ago. Today, the tundra landscape is changing more dramatically as temperatures change and warm seasons lengthen, with lines of trees soaring in elevation and plants growing to new heights in what we call “the greening of the Arctic”. And Myers-Smith, now a PhD ecologist, National Geographic Explorer, and professor at the University of Edinburgh in Scotland, is leading a team of researchers studying this change. They focus on shrubs, woody tundra species that seem able to react relatively quickly to warming conditions. Her fieldwork takes place primarily in the Canadian Arctic of the Yukon Territory. However, in recent years, due to pandemic travel restrictions, her team has been conducting research in an area closer to home: the Cairngorm mountains in Scotland, home to the last remaining patches of tundra in the UK. At the warm edge of the tundra biome, patches like these on top of the mountains slowly shrink as the trees grow upwards.

Among other things, Myers-Smith and his team are studying the leaves of individual plants to understand how shrubs are responding to warming. Root behavior is also an important piece of science history, but in this ecosystem where the ground freezes and thaws all year round, it’s impossible to leave a camera underground to film what’s happening under the ground. floor. Instead, the team is taking soil core samples – essentially the roots of shrubs growing in peat soils – to a lab to measure how the roots respond to warming over the course of a season, as well as from year to year. For this, the Myers-Smith team uses a printer with a high-resolution flatbed scanner, in this case a printer equipped with Epson’s Heat-Free technology which consumes little energy. Choosing to use a more efficient device is no accident; this helps to minimize the team’s impact on the environment in their research. Just as Myers-Smith’s research encompasses both landscape and micro-scales, our efforts to mitigate climate change must involve both large-scale solutions. and the daily actions of individuals, such as choosing energy-efficient appliances in our homes and workplaces.

“Coordinated actions will lead to more climate change mitigations,” acknowledges Myers-Smith. “But individual actions allow you to have power and to get involved in the issues, which is still just as important. I think about that a lot when I’m in the Arctic, about the people who live there and the actions they take. For them, it’s often about sharing what’s going on up there with the rest of us. So what we can change our ways of life and also advocate for change on a larger scale.

While Myers-Smith and his team typically work primarily in the Canadian Arctic, tundra permafrost covers almost a quarter of all land in the northern hemisphere, including Alaska, Canada, Greenland, Iceland, Scandinavia and Russia. His team compiles data from scientists from all these regions.

“If you find something on your own fieldsite, that doesn’t mean it’s happening on the next fieldsite,” says Myers-Smith. “But if you have people working in, say, sixty different locations across the Arctic, and most of those locations are seeing the same kinds of changes, that convinces me that’s a general signal.”

The Arctic has warmed more than twice as fast as the rest of the world, in part because of the cycle of change studied by Myers-Smith. As temperatures warm, the permafrost thaws, releasing some of the 1.7 trillion tonnes of carbon, nearly double the amount in the atmosphere, stored there, mostly in the form of animals and partially decaying ancient plants. And as the ground warms, plants grow taller and denser, capturing snow that acts as a blanket to insulate the ground and further accelerate warming to release more carbon. Myers-Smith also studied a factor in the fight against the warming of greening tundra: this new shade from taller plants could keep the ground cooler during the summer. “Summer shading offsets winter warming a bit,” she explains, “but the question remains whether it will continue to do so as we see more and more warming in this system.”

As the tundra greens, Myers-Smith says we are seeing strong implications for wildlife, especially the animals that people care about and depend on. When plants turn green in the spring influences when caribou begin their migration, where they end up in the Arctic, and the nutrients in their milk for their calves, all of which could affect caribou numbers. Other animals, such as moose and beaver, also move north out of the boreal forests as the tundra greens.

But just because these noticeable impacts are happening regionally doesn’t mean those of us who don’t live in that landscape can ignore what’s happening.

“A lot of us think of the Arctic as this very distant, remote place. But almost everywhere in the world there is someone,” says Myers-Smith. whose global systems are working means accelerated tundra warming will eventually head south.”Change matters everywhere, and so do our actions.”