Bark beetle continues its march in Switzerland

A bark beetle in flight Beat Wermelinger, WSL

Scientists are sounding the alarm after the bark beetle damaged 320,000 cubic metres of spruce in 2017 – 3-4 times more than in the period 2008-2012. They are warning of a worsening situation this year.

The Swiss Federal Institute for Forest. Snow and Landscape Research WSLExternal link said the rise in damage caused in 2017 was “worrying”, in a statementExternal link released on Thursday.

Storm, snow and the hot summer weather have stressed the spruce further, leaving them more susceptible to attack by the pest species, which prefers weak or not-long-dead trees for breeding, the WSL said.

“Even if there are some regions which have little beetle damage, we can no longer say that the situation has calmed down,” experts were cited in the statement as saying.

The WSL expects an increase in the beetle population this yearExternal link. The winter storms, such as Burglind, of earlier this year have already caused damage to the spruce population. 

A storm and beetle-damaged tree Waldschutz Schweiz, WSL

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

+ Read more about storm Burglind here

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, the WSL says.