Warming Arctic climate may mean trees for Nunavut in 100 years
Fossil forest holds clues to future climate
A Université de Montreal graduate student studying a fossilized forest on Nunavut’s Bylot Island says the climate conditions that existed there about 2.7 million years ago are similar to what scientists predict will exist again in a hundred years.
In other words, what goes around, comes around: it’s possible that small trees, similar to the willow, pine and spruce that now grow at the treeline near James Bay in Quebec, might one day grow again in the High Arctic.
“I reconstructed the climactic conditions associated with this forest and these conditions were similar to what we expect at the end of the century with the advent of climate change,” said Alexandre Guertin-Pasquier.
“Maybe, at the end of this century, we will have the conditions that permit the growth of this kind of vegetation. You might be able to take a seed of something we found there and plant it. It’s not impossible that the treeline could reach Bylot Island in the near future.”
Pollen and seed transport, and the formation of soils, would have to take place first, he added, before the actual treeline marches fully north.
Guertin-Pasquier, an aspiring science journalist who did field work at the Bylot Island site in 2009 and 2010, presented his findings at the April 2012 International Polar Year conference in Montreal.
Located high atop a barren plateau on the south-western plain of Bylot Island, about 80 kilometres north of Pond Inlet, the fossilized forest, thought to be more than two million years old, was first discovered in 2001 by Daniel Fortier, then a Université Laval student.
Fortier happened to be walking by a river in a valley on the island when he noticed a branch sticking out of the snow. It had apparently become exposed through erosion on the banks above and washed down into the river valley.
Fortier and his colleagues later climbed the slope and found more perfectly preserved wood specimens near the top of the 500-metre plateau.
Guertin-Pasquier specializes in sedimentology, the study of sediments such as sand and mud, and how they get deposited, in an effort to understand the earth’s geological history.
The Bylot Island fossil forest site, which is contained within Sirmilik National Park, is layered with glacial till and organic units. The fossilized wood is contained in a layer of peat which is covered over with sand, gravel and rocks deposited by retreating glaciers. The lack of oxygen in the peat, the rapidity of burial and stability of the permafrost, all helped to preserve the wood, Guertin-Pasquier said.
He and his colleagues collected samples of the sediment to examine it for pollen and other preserved organic material. The age of the organic deposits ranges between 2.6 and 3 million years old, he said, based on scientific analysis.
When Guertin-Pasquier analyzed the pollen, he was able to paint a picture of a warmer and more humid environment, 10 to 15 degrees Celsius warmer than present, where pine, spruce, larch and willow species grew and even some leafy species such as oak and hickory.
Thirty-five wood pieces, most of them up to 25 centimetres in length and weighing up to a kilogram, were also collected.
“I was surprised by the height of some of the trunks we found here,” he said. “The biggest trunk we found was 2.5 metres and it wasn’t a full trunk so the tree was bigger than that, probably five metres high.”
It’s an odd thing to imagine on a bare landscape where today, nothing grows above your knee.
Amazingly, the specimens still smelled like wood, Guertin-Pasquier said, and some still had bark on them—similar, he said, to the wood samples collected at the Beaver Pond fossil forest site on Ellesmere Island.
It’s still unclear how the trees managed to live through the polar winter with no sun. Perhaps they entered a dormant period, he said, but scientists don’t know for sure.
While there, Guertin-Pasquier and his colleagues drilled several boreholes in the ground roughly 10 centimetres in diameter and one-to-two metres deep, to complete work begun in 2009 but much of the digging was done by hand, with shovels. Because of the density of the permafrost, progress was slow.
“We can dig only 10 or 20 cm a day. It takes a month to dig only seven holes,” he said.
“We also had to work with extreme wind which often occurred on the top of this plateau. Sometimes the wind was 80 km/h or something like that. On those days, we just took a break. It’s difficult to work under those conditions.”
The most enjoyable thing—aside from the spectacular 360-degree view atop the plateau and the meditative peace that comes from working in the field in 24-hour sunlight with little outside contact—was setting up an information table at the Tununiq Sauniq Co-op in Pond Inlet.
“Visitors were curious. They asked questions. Some Inuit told me that they also had dug up trunks of wood around Pond Inlet so maybe there are other fossil forests around there. Maybe a future project will be to find that other forest,” he said.
Mittimatalingmiut also told him they were concerned about changing vegetation, animal migrations and animal life cycles which they attributed to changing weather patterns over the past few decades.