After the ash trees, the beech trees are also victims of a disease that is gaining ground in Quebec and is worrying the experts.
Posted at 12:00 a.m.
Julie Bouchard, forest pathology biologist at the Ministry of Forests, Wildlife and Parks, has been closely following the development of the disease for years now.
Beech bark disease, she explains, is the result of “an interaction between an insect, the beech mealybug, and two pathogenic fungi.”
“Although the disease is most often associated with the presence of these insects, climatic stresses, including summer drought events, high temperatures and extreme cold, make beech trees more vulnerable,” she continues.
The disease, which is first visible on the trunk of the tree, is constantly gaining ground, so while some areas seemed spared during the last survey in 2019, this may very well no longer be the case.
The extent of the damage is still very variable. In most of Estrie, for example, the disease was already present in 2019, but we were not yet “at the most advanced stage of the infection”, explains M.me Bouchard.
PHOTO PROVIDED BY THE MINISTRY OF FORESTS, WILDLIFE AND PARKS
Beech bark disease is most often associated with the presence of an insect, the beech mealybug.
In this region, out of 13 sampling stations, one outbreak was significant and at the last stage of the disease in La Patrie and another, in Chaudière-Appalaches, very close to Estrie (in Saint-Hilaire-de -Dorset).
“The disease is now moving north, continues Mr.me Bouchard. Half of the Laurentians is in the second stage of infection of the disease”, the disease being particularly advanced in Prévost.
Beech scale and the causative fungus are exotic species that were accidentally introduced near Halifax Harbor in 1890. The first symptoms of the disease were detected in natural forests in 1911 and the first mention of the disease , near Lake Témiscouata, dates back to 1965.
Beech, important for the black bear
Although beech is not “a very sought-after species”, all of this is worrying, continues Mme Bouchard, who has this tree at heart. “This is a species native to Quebec and plays a super important role in the natural forest”, in particular because the presence of beech has an impact on the birth rate of the black bear, which eats its fruit. .
What should be done ? Can we still save the beeches? Alas, there is no miracle cure, answers Mme Bouchard, who advises those who have them on their land to be attentive to changes and, if necessary, to cut branches.
What to do with beech in your yard?
Jacques Brisson, professor of biology at the University of Montreal, says that the fight against the disease is not easy and that it is impossible on a large scale, in a forest.
However, he suggests to citizens who want to save their tree – often unloved, especially in maple groves, he also notes – to send a fairly powerful jet of water on the bark, each year. If the problem is taken care of early enough and if a lot of scale insects are dislodged, Mr. Brisson is hopeful that this can save the tree. “But when the fungus has entered and has already done a lot of damage, then it’s more complicated. »