Swiss forests under attack from bark beetle

Bark beetles often attack trees that are already weakened by disease, drought, or physical damage. Keystone

The level of spruce trees in Swiss forests damaged by the bark beetle has reached its highest in more than a decade.

A survey by the Federal Institute for Forest, Snow and Landscape ResearchExternal link found that 735,000 cubic metres of spruce suffered damage last year – more than twice as much as in the previous year.

Experts say the worsening situation is due to hot and dry weather as well as storms that have weakened the trees, leaving them susceptible to attack by the beetle which prefers dead wood for breeding.

The institute says it might take some time for the situation to improve as climatic conditions have allowed the beetle to develop up to three generations.

Forestry experts recommend removing damaged and beetle-affected trees as soon as possible to limit the spread of the bark beetle.

Spruce makes up around a third of the growing stock in Switzerland. It is the most important timber tree in the country and spruce forests often have a protective function in the mountains.

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