It is not just fires that are ravaging our forests and especially our spruce trees. There is in fact another threat, silent and less spectacular but just as devastating: bark beetles. Fearsome insects that dig galleries in the bark of conifers to lay their eggs and decimate entire forests.
These beetles are pests for forest ecosystems. If the insect, very fond of conifers, first and mainly attacked the Grand-Est, it is now the whole of France which is gradually affected. Faced with the scale of the damage, the State has organized the response and is taking new drastic measures this Monday to try to eradicate this threat. The Minister of Agriculture Marc Fesneau, traveling in the Vosges, presented a national plan called “bark beetles and wood crisis” because the entire professional wood sector is endangered by these xylophagous attacks.
Who are these bark beetles?
These small, devastating creatures, a few millimeters long, with a brown shell, feed on wood. Bark beetles benefit from global warming and are particularly attracted to trees that have been weakened or stressed, particularly by factors such as drought, storms, fires or disease. They dig galleries under the bark of trees, thus disrupting the circulation of sap and gradually weakening the tree until it dies. Bark beetles can spread quickly through a forest, causing millions of trees to die in a short period of time.
A global attack
An impact on ecosystems, but also for professionals in the wood industry. Thus, since 2018 the volume of affected wood is estimated at 37 million cubic meters, and a fifth of coniferous forests are affected in the large North-East quarter. For the year 2020 alone, still in the Grand-Est region, it is estimated that 3.3 million m3 of decommissioned wood, that is to say which have lost their value, attacked by an insect or for another due to dieback, including 1.8 million m3 of spruce trees, estimates the National Forestry Office. Usually valued as timber for framing and joinery, spruce trees attacked by the bark beetle are downgraded by sawyers, in particular because of the development of a fungus which accompanies the bark beetles and which turns the wood blue. This unusual influx of dying wood in France, but also in Europe, led to a fall in sales prices and saturation of the market.
The choice of weapons
Chemical or alternatives, that is the question. Although most experts agree on the need to act quickly to control bark beetle populations, there is debate and controversy over the best strategies to adopt. Scientists are working on developing organic or ecological methods to reduce reliance on pesticides and other potentially harmful chemicals. However, the urgency of the situation fuels many debates.
Weapons of response
Faced with this growing threat, the authorities have decided to intensify their efforts. These measures included increased monitoring of its parasite populations. Government agencies and researchers are tasked with detecting any signs of infestation as quickly as possible and taking preventative measures. Surveillance, but also the establishment of quarantine zones in certain affected regions to limit the movement of infected trees and reduce the risk of spread of bark beetles. Finally, the State is trying to raise public awareness to inform them of the risks but also of the measures to take to prevent the spread of these parasites.
This Monday, the new “bark beetle and crisis wood” attack plan plans to improve the possibilities for using bark beetle wood, in order to promote their market. “It is essential to change our posture and be proactive, to demonstrate inventiveness and boldness to collectively find solutions that meet the challenges,” declared the minister.
The attacked trees can thus be used to power biomass power plants. For this, the government is putting in place a temporary exemption. Objective, to allow the replacement of fresh wood with crisis resinous wood (firs or spruces that are dry or attacked by bark beetles). Other measures announced include financing new trees planted, in return for encouraging the diversification of species during reforestation. Last but not least, help for woodworking professionals affected by bark beetles in order to finance the purchase of machines… Because cut and debark trees, to prevent bark beetles from spreading to other healthy trees nearby , it’s expensive…