Here’s some good news for the animals that live in Eastern Canada’s boreal forest and the forestry industry that operates there — the trees that dominate the boreal forest can do just fine in the warmer, drier temperatures expected with global climate change.
Black spruce are found across North America from Newfoundland to Alaska, and are the most common tree in the eastern boreal forest.
A new study has found that in Quebec north of the 49th parallel, black spruce seem to thrive and grow better in warmer, drier years, which are expected to become more frequent with climate change.
“That area might be a refuge for all these migrating birds or all these species that use this habitat — it is good news,” said Loïc D’Orangeville, lead author of the new study, published this week in the journal Science. D’Orangeville is a post-doctoral researcher at the University of Quebec in Montreal and Indiana University.
Animals that rely on the eastern boreal forest include many songbirds that nest there, caribou, snowshoe hare, lynx and sable, he said, adding that black spruce are also important commercially for use in the pulp and paper industry.
Unfortunately, the new study shows that Quebec trees south of the 49th parallel, which require more water due to the longer growing season, grew less well during warmer, drier years. That’s similar to what’s been found for black spruce farther west, where there is less rain.
Still, the study predicts that between 2041 and 2070, based on median climate warming projections, about 70 per cent of Quebec black spruce trees between the 49th and 52nd parallels should grow better than they do now.
They could also spread north. Already, they grow in patches up to the 58th parallel, D’Orangeville said, “so we don’t see really massive obstacles that would inhibit them moving northwards.”
However, he cautioned that the study only looked at the trees’ direct response to higher temperatures and drier conditions and not the impact of side-effects of climate change such as an increase in forest fires and insect outbreaks: “These could really change the portrait.”
Growth of 16,000 trees studied
The study looked at the growth of 16,000 trees across 583,000 square kilometres of Quebec south of the 52nd parallel between 1960 and 2004. D’Orangeville and his colleagues examined the growth rings in core samples drilled by Quebec’s Ministry of Forests, Fauna and Parks across the province over many decades.
The ministry takes pencil-shaped “biopsies” from the trees and looks at the rings from just the past few years to monitor the health and productivity of commercial forests.
D’Orangeville analyzed decades of rings with the help of a computer program.
He said that normally researchers have access to hundreds of samples at most. The much larger data set in this case generates more complete, reliable results.
“That really emphasizes the importance of government funding into this monitoring work and the long-term data, how important it is to get a good grasp of how ecosystems doing,” he added.
The new findings will be useful to conservationists and foresters.
“The productive forest is migrating north,” said D’Orangeville, noting that the industry is already aware of that and recalibrating where logging is allowed.
People also need to consider where millions of black spruce trees are going to be replanted each year to replace stands that have already been logged.
“In terms of conservation,” he added, “if you want to protect, for instance, the black spruce ecosystem in Quebec, you have to think about the future of the ecosystem, where it’s going to be in the coming decades.”