Fungus kills pine trees weakened by last year's drought

Anyone who travels around the rolling countryside of Central Bohemia these days will be greeted by a sorry sight: hundreds of brown patches marring the perfect greenery of the mixed forests of that hilly region. Thousands of fir trees are dying in Bohemia but what exactly is causing them to wither and how serious is the situation? Pavla Horakova reports.

Fungus kills pine trees weakened by last year's drought

On a few day trips I have recently made to places around Central Bohemia I could not fail to see the brown-orange conifers dotting the green wooded hills. It is a sight that Czechs were used to in mainly the 1980s when entire forests in the mountains in the west and north of the country turned brown and died as a result of industrial air pollution. This time it is only individual trees that are dying.

I spoke to Frantisek Soukup, a forest protection expert from the Research Institute of Forest Management and asked him what exactly was wrong with Czech conifers.

"The trees in question are the European black pine and the Scots pine. They were severely affected by last year's drought. The trees are weakened as a result of several periods when there was hardly any rain and they are more susceptible to disease or parasites. They have been affected by two fungi: it is pine tip blight or Sphaeropsis Sapinea in the case of the black pine and the Scots pine is predominantly affected by a fungus called Cenangium Ferruginosum."

Healthy trees can resist the fungi. Only weak ones succumb.

If more than half of the branches are dry, there is very little hope that the tree will regenerate even if the water reserves in the soil are replenished. Dr Soukup says such trees have to be felled and removed from the forest as quickly as possible.

"It is necessary not only for aesthetic reasons but also the quality of the timber deteriorates if the dead tree isn't felled quickly. But what's more important: the dying trees can become infested with bark beetles or other woodworms. If the insects multiply excessively, they can infest the living, healthy trees as well."

Pines are dying mainly in certain areas of Central, North and West Bohemia. I asked forest protection expert Frantisek Soukup just how serious the situation was.

"We can say it is a disaster of unusual size. There were several such disasters in the 20th century but on smaller areas. This year, a larger part of the country is affected - it goes to hundreds."