Climate change could slowly alter local landscapeCanadian Forest Service re-measures plots established in 2007
Northern News Services
Thursday, July 27, 2017
Though it's a long process with many complicating factors, if the climate were to continue changing in accordance with recent trends, that could mean some significant landscape changes up and down the Mackenzie Valley.
The edge of this peat plateau south of Inuvik shows the impact of thawing surface permafrost. The dry, lichen-dominated surface of the peat plateau is replaced by very wet, mossy vegetation as the thawing causes the ground surface to sink approximately 50 cm. As can be seen to the right of the photo, this increasing surface wetness appears to have caused the death of some trees. - photo courtesy of Ruth Errington
Ruth Errington, technician with the Canadian Forest Service, was in Inuvik this month re-measuring peatland and forest plots around the community that were established in 2007 during the International Polar Year.
The service has 69 plots throughout the Mackenzie Valley, from the southern border to Inuvik. The Mackenzie Valley is predicted to be one of the most sensitive areas to climate warming in Canada.
Errington studies peatland and peat plateaus, which are permafrost-containing bogs or areas of near-surface, ice-rich permafrost. Basically, they are wetlands where the soils are so cold and wet that dead plants rot more slowly than new plants grow.
"It's a big sponge that when it freezes, the ice expands, like you'd see in an ice cube in a freezer," she said. "When it collapses, it loses volume."
Ruth Errington, technician with the Canadian Forest Service, has been re-measuring peatland and forest plots in the Mackenzie Valley this summer, part of a 10-year checkup after establishing the plots during the International Polar Year in 2007. - Stewart Burnett/NNSL photo
The collapse of the permafrost could lead to dramatic changes in vegetation and landscapes.
It's a long process for these sort of environment effects to take place, but if the permafrost were to thaw, lichen and trees would be lost, at least for a period of time.
"It's a very dramatic change on the landscape," said Errington. "You lose things like caribou forage in the lichens. You would lose the ability to move across the landscape area quickly too (because of how wet it is)."
After the thaw, areas would eventually drain out into rivers and the landscape would become much more dry.
On a long enough timescale and with current trends continuing, Errington predicts the landscape around Inuvik would start to look more like the Sahtu, which itself is starting to look more like the Dehcho once did.
"These things don't change overnight," said Errington. "There's inertia in the system. Things are adapted and you often need a disturbance to reset the ecosystem."
Sites this far north are very good at insulating permafrost and keeping it intact too, she added.
For now, Errington will be taking her research back to Edmonton to study it over the winter. She hopes to be able to re-check the plots again in another 10 years and better map the changes over time.
"I think for the most part Inuvik has been pretty stable," she said before being able to analyze her data properly. "But we'll see. It would be a subtle change at this point."