Louise Sallé, edited by Alexandre Dalifard 06:11, December 28, 2022
Mild winters, like the one we are currently experiencing, are not without consequences for trees.
The National Forestry Office (ONF) is concerned about the disruption of the biological cycle that this could cause.
The buds risk, in fact, to appear too early, and to weaken at the slightest cold snap.
Temperatures are on the rise again this Wednesday, as we have just experienced the second hottest Christmas on record in the country.
New Year's Eve should also break records, Météo-France announcing temperatures above 15 ° C on Saturday afternoon, and up to more than 20 ° C in the Southwest.
A pleasant thaw for us, but fatal for nature, in particular the trees which suffer significant consequences.
Summer drought is not the only scourge linked to global warming that damages forests.
Mild winters are just as dangerous.
Buds already present?
The buds risk, in fact, to appear too early, and to weaken at the slightest cold snap.
Xavier Bartet, deputy director of the research, development and innovation department of the National Forestry Office (ONF) has already noticed their presence.
"Yesterday I felled a tree and saw that the buds of the tree were opening," reports the forest engineer.
"I wonder if, in fact, the significant heat of recent days has not caused a winter outbreak of buds," he wonders.
"It's something completely anachronistic compared to the usual cycle of the tree", underlines Xavier Bartet.
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A need for cold to respect the "dormancy" period of the tree
Trees also risk producing nothing at all, forgetting to come out of their "dormancy", that is to say their period of hibernation.
“When the tree is in its vegetative rest, it needs several weeks of fairly severe cold so that the buds can then develop,” says Xavier Bartet.
"If ever there is a disturbance in these episodes of cold, the lifting of dormancy risks not being done, and we can observe the following year completely devastating effects on the cycle of the tree", he continues. .
An unstable climate also harmful for Mediterranean species
Finally, winter heat is also problematic for new species from the South, such as maritime pine, which are introduced in France to help forests better resist heat and adapt to climate change.
However, the sudden alternation of mild periods and much cooler ones harms the growth of these trees.