Anthony Taylor, a forestry professor at the University of New Brunswick, was heading down a highway in the spring of 2018 when his wife noticed clumps of red-colored trees.
Taylor recognized that they were dead balsam firs and so launched a research project to examine what was killing many Canadians’ favorite trees to decorate their homes at Christmas.
Six years later, in a paper recently published in the journal “Frontiers in Forests and Global Change,” Taylor and his co-authors identify the cause of mortality in western New Brunswick and eastern Maine as drought and high temperatures caused by climate change.
“Identifying large-scale climate anomalies, such as drought, associated with the sudden balsam fir mortality reported in 2018 could be useful in determining the likelihood of future mortality in response to climate change,” says the study.
Taylor said he was shocked by “so many” balsam fir deaths.
“It’s completely abnormal to witness such a large-scale death of these balsam fir trees,” he said in a recent interview. “And it really stood out.”
Balsam fir makes up about 20 percent of all trees in New Brunswick. But with its fragrant needles and triangular shape, the tree is most often associated with Christmas.
More than 95 per cent of Christmas trees grown in the province are balsam and about 200,000 of them are exported, mostly to the United States, Taylor said.
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After his observation of the highway, Taylor, along with James Broom of the University of New Brunswick and Loïc D’Orangeville of Laval University, began analyzing various causes that could have killed the trees, including pests and climatic data.
New Brunswick experienced a drought in 2017 with hot, dry days in summer and a warm fall, and their analysis showed that balsam fir is particularly sensitive to drought and high temperatures. “That dry, hot growing season the previous year significantly stressed these trees and led to their demise the following year, in 2018,” Taylor said.
The team also looked at historical data and discovered a similar weather event in 1986, when balsam fir trees died due to drought and heat the previous year. “This further reaffirmed our study … that climate was indeed driving the mortality we saw.”
Fred Somerville, president of the Canadian Christmas Tree Association, said the balsam fir is one of the most popular trees for Christmas, the others being Scots and white pines and the Fraser fir. The balsam fir, he says, likes cold winters and hot, humid summers.
Somerville, who has a farm in Alliston, Ont., about 90 kilometers north of Toronto, said climate change is making the weather unpredictable. “For now, it’s not so much the heat as the lack of rain that would hurt us,” he said. “Over the last decade, I would say we’ve had several dry years, drier than we would like. But the last two years haven’t been too bad.
A lack of rain kills young or even newly planted saplings, Somerville said. Older trees’ growth is stunted when they don’t get enough rain, and they don’t have that vibrant green sought after at Christmas, he said.
Matt Wright, a Christmas tree grower who runs M. Wright Farm and Forest Ltd. in Nova Scotia, said climate change and heat are affecting most conifers, including balsam fir. “The roots are having trouble because of the heat,” he explained, adding that new parasites are appearing and attacking the trees.
“Climate change has led to a shift in the population dynamics of some insects, especially those that overwinter in the ground, because we don’t get deep freezes or cold temperatures that regulate when they could emerge or even survive “Wright said.
Taylor said heat and drought have weakened balsam firs, making them more vulnerable to pests and diseases they could otherwise defend against. More research needs to be done to understand how climate change will affect pests and Christmas trees, he added.
Some ways to mitigate the effects of climate change include planting different species to improve forest resilience and monitoring weather conditions, he explained.
Last year was one of the hottest on record and 2024 is expected to surpass it, he said. Although the loss of balsam fir in 2018 is rare, it will likely become more common with global warming, he added.
“The Christmas balsam trees that we all love, you know, unless we do something about climate change, we’re going to have a lot less of them in 25 to 50 years,” Taylor said. “If we continue on this path, by the end of the century there will be very few balsam fir trees left. »
This report by The Canadian Press was first published December 8, 2024.
© 2024 The Canadian Press