Wood fossil a glimpse of Northern Canada’s forested past
Laval researcher sees branch in the snow on Bylot Island
MONTREAL — Another remnant of Nunavut’s warmer past, of a time when forests covered the Far North, has been uncovered on Bylot Island near Pond Inlet.
Some two million years ago, birch and spruce trees flourished on what is now a barren plateau, located not far from a valley filled with towering sandstone formations called hoodoos.
Last summer, a young researcher from Université Laval in Quebec City was walking by the river that runs through this valley and saw a branch sticking out of the melting snow.
“Since there are no trees on Bylot Island, it immediately caught my interest,” said geographer Daniel Fortier.
The wood had apparently washed down from a nearby slope. Later, Fortier walked up the slope and found several other small pieces of wood on the hillside.
But he couldn’t pursue the trail. His camp was on the other side of the river, which, because of the spring melt, soon became impassable except by helicopter.
He was forced to wait for three weeks before a helicopter became available.
Touring over the terrain, Fortier and his companions found more pieces of wood and, finally, came on the apparent source on a windswept plateau, 400 metres high.
“When we were on top, we saw a piece of wood,” Fortier said.
Erosion had likely caused this wood to surface, as other researchers had previously been in the same place and not noticed a thing.
After digging down through a layer of sediment, they uncovered another layer of well-preserved vegetable matter, or peat, comprised of plants, leaves and wood.
“The state of the peat is like that of peat 200 years old,” Fortier said.
Its well-preserved state means the peat was probably submerged quickly in deep water. This water protected it from the passage of the huge glaciers, that eventually covered the land.
Analyses of the peat show it includes parts of birch and spruce trees and is about two million years old.
The forest lies inside Sirmiliq National Park, and Parks Canada has been advised of the new discovery within the park’s borders
“We know it will be well protected,” Fortier said.
It’s not the only forest in Nunavut where ancient trees and plants are petrified, that is, turned to stone, or mummified.
Forests grew in the high latitudes from about 45 million years ago to approximately two million years ago when a colder, glacial period started.
Some plants and trees from these long-vanished forests didn’t turn to stone or oil, but, stored in the polar deep freeze, kept their original form and tissue and remained nearly as fresh as today.
Forest layers the same age as Bylot Island’s have also been found on Axel Heiberg Island, Ellesmere Island and Banks Islands.
But Bylot Island’s new forest is the most southerly fossil forest found in the High Arctic.
“It fits a pattern,” said Jim Basinger, a paleo-botanist from the University of Saskatchewan who has studied Axel Heiberg’s fossil forest. “But it extends the range a heck of a lot to the southeast.”
Scientists still don’t understand how forests grew through the polar night, because there are no similar forests growing today where trees have to sit in the dark for three months.
A further study of these ancient forests may provide a better understanding of how they grew and what their presence says about the impact of climate change.
Despite the potentially catastrophic nature of climate change, global warming may bring back productive forests — the lungs of a healthy planet — to the high latitudes.