Swiss launch fight against forest pests

Bark beetles have destroyed two million cubic metres of spruces in Switzerland Keystone

The Swiss authorities are stepping up their efforts to combat bark beetles, which have ravaged Switzerland’s forests like never before.

Cantonal forestry bosses said their top priority was to stem the spread of the destructive insect in mountain forests, which act as a barrier against avalanches.

In 2003, bark beetles infested a record 17,000 new areas in Switzerland.

“Bark beetles are barely visible but the damage they cause can be enormous,” Walter Schwab, president of the cantonal forestry conference, told swissinfo.

“They reproduce exponentially and they can be endemic.”

Last summer, the five millimetre-long beetles destroyed two million cubic metres of spruce trees – the biggest amount ever – when record temperatures sparked a plague of bark beetles in the country’s forests.

Cantonal foresters said limited finances prevented them from launching nationwide measures and reforestation projects. Tackling the problem locally was their only option, Schwab explained.

The federal budget available to fight bark beetles has been cut to SFr18 million this year from SFr35 million in 2003 because of public spending cuts.

Timber production

On Friday, cantonal foresters said they planned to fell old trees in key areas to allow room for young trees to grow. Priority will be given to forests which protect against avalanches and rock fall.

“If nothing is done to fight the beetle, a high number of trees will die and it won’t be possible to maintain our timber production,” said Beat Forster, a scientist at the Swiss Federal Institute for Forest, Snow and Landscape Research.

Bark beetles are particularly attracted to spruces, which make up the majority of trees in Switzerland. But in some areas, nothing can be done to save the spruces – once the beetles have nested in the bark of a tree, it will eventually die.

Schwab also warned that the success of the campaign depended to a large extent on the climate.

Last summer’s hot and dry weather created perfect conditions for the beetles to thrive and reproduce in record numbers, while rain acts as a deterrent.

“We have to get used to the sight of red, discoloured forests,” he said.

swissinfo, Karin Kamp

Key facts

Bark beetles infested a record 17,000 new areas in Switzerland in 2003.
The insect destroyed two million cubic metres of spruce trees last year.
The beetle has an average life span of 18 months.