In wildfire season, sometimes you can’t see the tundra for the trees. Most Northwest Territories communities facing any kind of wildfire threat are the ones in the boreal forest. For obvious reasons, the forest gets all the attention. That’s where the fuel and danger is. As a result, nobody has really been counting the tundra fires that occasionally appear north of the treeline. But those fires may be evolving, and that may have consequences that warrant our attention.
Tundra fires burn across stretches of barren grassland. Nunavut had a brush with a tundra fire last year when one was seen near Bathurst Inlet, but they are mostly quite small and far from any community. As a result, recording them is tricky. If a fire rolls across the tundra and nobody sees it, who’s to say it ever happened? Matthew Hethcoat and his colleagues are trying to answer that. Hethcoat and colleagues at Natural Resources Canada’s Northern Forestry Centre began by studying satellite images from 1986 to 2022.
They trained software to know the difference between burned and unburned pixels of those images, then asked the software to find potential fires that nobody noticed over those decades. After that, humans reviewed the software’s suggestions to make sure there were no false positives. The result? Before this work, there were around 60 recorded tundra fires north of Canada’s treeline between 1986 and 2022. The team found 209 new ones that hadn’t previously been noticed. In the grand scheme of things, over more than 30 years, that’s not many – about six a year that had gone unrecorded.
Hethcoat and his colleagues are sure there are more tundra fires to be found that their technique didn’t pick up. Their first attempt, published in the journal Remote Sensing this month, is just the start, he said.
