Canada’s swamps are the secret weapon in the fight against climate change, experts say – fr

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Canada’s swamps are the secret weapon in the fight against climate change, experts say – fr


They may be one of the most overlooked landscapes, but scientists say Canada’s marshes have an important role to play in the fight against climate change.
Peatlands, marshes and wetlands across the country are the secret stars of carbon capture, but most people don’t realize their value, said Christina Davy, a research scientist at the Ministry of Natural Resources and Forestry. Ontario.

“Because they look like big puddles of mud when you don’t understand how important they are, I think we don’t always give them the value they really deserve,” she said. What the hell host Laura Lynch. “And I think people understanding why they’re important is a big step forward in keeping them and slowing the rate of loss. “

Davy, who heads a conservation ecology lab at Trent University in Peterborough, Ont., Is among a number of scientists singing the praises of Canada’s carbon-catching swamps, sounding the alarm bells on the saving what is left and restoring them where possible.

Davy collects a water sample in a wetland. (Anne McCarthy)

Urban encroachment and agriculture have replaced about three-quarters of wetlands in heavily populated southern Ontario, she said, but there is significant loss of wetlands across southern Canada. .

Gail Chmura, professor in the Department of Geography at McGill University, studies the salt marshes around the Bay of Fundy, between Nova Scotia and New Brunswick. She describes these wetlands as “grassy meadows that are flooded by ocean tides twice a day.”

They are mostly herbal with a few wildflowers in the mix. “And that’s what makes them such a good carbon sink, because they have huge root systems that store the carbon dioxide that plants take from the air,” she told Lynch.

Geographer Gail Chmura studies the salt marshes around the Bay of Fundy, between Nova Scotia and New Brunswick. (Submitted by Gail Chmura)

Like all plants, they undergo photosynthesis, during which they extract carbon dioxide from the atmosphere and store it in the green part of the plant.

“But, also, three to five times more is stored in organic matter – in the roots of the soil. And those roots stay there in this type of ecosystem. They don’t break down much because the soil is so wet and they keep accumulating more and more soil as the sea level rises. ”

Since this has been happening for millennia, “we have 3,000 years of carbon stored in these swamps,” Chmura said.

By testing the soil at the site, she and her colleagues calculated that the swamps contain an amount of carbon equivalent to driving a vehicle 225 billion kilometers.

While 77% of the region’s marshes have been lost to dikes and drainage, Chmura said, their restoration is actually relatively straightforward. “If we open those dikes, the tidal water starts coming in and settles all that Bay of Fundy mud very quickly. “

Dipper Harbor Salt Marsh, located on the Bay of Fundy. (Submitted by Gail Chmura)

At a restoration site in Aulac, New Brunswick, they found the carbon capture to be “way above anything we expected” after just six years, she said.

“They immediately serve as huge carbon sinks – as good carbon sinks as the undisturbed marshes in the same region. “

On the opposite coast, where Mervyn Child’s Indigenous ancestors depended on the Kwakiutl First Nation wetlands for food and health, another effort is underway to restore and protect the region’s rich saltwater marshes.

This is not only good for carbon capture, but also for the local watershed and the wildlife within.

“There is so much waterfowl, of course, in there. There are a lot of migratory birds and there is salmon – chum, pink and coho in there – and a variety of trout, ”he says.

In March, the community won a grant from the Government of British Columbia to help reverse the effects of logging and erosion there.

Rising sea levels and increasing intensity of storm surges threaten the balance between fresh and salt water, Child said. Additionally, nearby logging filled a local river with so much debris that it diverted elsewhere through the forest, disrupting salmon habitat and completely wiping out a treasured local swimming hole from its youth.

Enhance wetlands

Part of creating the drive to protect wetlands is giving them an award, said Sheri Young, climate change and energy specialist from the town of Okotoks in southern Alberta.

“We decided to count all the natural assets… that provide services to the town of Okotoks – air quality, carbon sequestration and stuff like that. that goes for us as a city, ”Young told Lynch.

This figure was $ 3.2 million.

Now, when developers knock on the door, or when it’s time to figure out where to place a bike path, everyone has “a general idea of ​​its value.”

[Alberta] has many natural assets and we want to preserve them and put our roots deep in the ground… to preserve it.– Sheri Young, Climate Change and Energy Specialist

With a limited supply of water and a climate that has warmed to more than double the global average over the past 100 years, Okotoks has good reason to preserve its wetlands, which are helping to counter the warming ‘effect. urban heat island “of all these homes and roads,” Young says.

She said it was crucial to restore wetlands for their own good, but also to counter the 404,000 tonnes of carbon the city emits each year and to adapt to increasing storms and heat events there. -low.

“I live here. I have children here. I have roots here. And… there is nowhere better. Canada is a lovely place. Alberta is a wonderful place. It has a lot of great natural assets and we want to preserve them and drive our roots deep into the ground… to preserve it. ”


Written by Brandie Weikle. Produced by Molly Segal, Jennifer Van Evra and Serena Renner.

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