Autumn comes early this year to Europe's trees
Autumn leaves, Velebit, Croatia.
Yellow leaves are lining forest paths throughout Europe — an unusual sight in August. Deciduous trees are losing their leaves on average 6–8 weeks earlier than usual. This is a reaction to the severe stress brought on by lack of rainfall and high temperatures this year in Europe. It is also a sign that trees are weaker and could become severely affected by insects and diseases next year. The combination of fires and drought this year following floods last year highlights the rapid changes in climate in Europe that forests have to deal with. Before governments adopt emergency measures to react to the situation, WWF is calling on all European governments to take a longer-term view and to assess the risks of climate change on their forests and implement adaptation strategies in the forest as a matter of urgency. A key solution will be to encourage more natural forests and natural processes which are more resilient to climate changes.Forest fires have raged across Europe during the long summer heatwave, as far north as Sweden and as far east as Russia. In Spain, Portugal, Italy, and Greece, the average total burnt area has quadrupled since the 1960s, with this year the worst year on record. The fires have been made worse by the very dry conditions in the forests. However, a new emerging threat is becoming known. All over Europe the soils have dried out. In many regions of Europe, only half the usual rate of rain has fallen between March and July, and much of this in short heavy downpours. Worn out by drought and fire, Europe´s trees can now no longer cope. They are showing severe stress symptoms. Dropping their leaves is one of them. Yellow leaves on the ground is usually the first sign of autumn — but in August? “Dropping leaves is an emergency reaction by trees. But it only shows us the tip of the iceberg. Many trees are severely affected, especially those that do not grow in their natural environment,” says Duncan Pollard, Head of WWF's European Forest Programme. “Governments need to take urgent action to help our forests cope with these unusual weather patterns.”The crisis is most obvious in hardwood trees, which protect themselves by shedding leaves which take a lot of moisture from the tree. However, trees which will incur the most lasting damage are those with short roots like spruce. The effect is even worse if such trees are planted in areas where they normally don’t grow. WWF fears that the stresses which Europe´s forests are subjected to could make them more vulnerable to pests and insects. “Diseases typically attack weakened trees. Drought stresses the trees which makes them more susceptible to diseases,” said Duncan Pollard.As a long-term measure, WWF calls on governments to reduce greenhouse gas emissions which speed up global warming. However as a short- to medium-term measure, governments need to assess the risks posed by climate change and, in reacting to the events of this summer (drought and fire), prepare adaptation strategies that will have lasting success. Forest administrations and foresters need to be aware of the effects of climate change and adapt their management and their species choices accordingly. Concrete measures should include:
• Restoring natural forests, which are generally more stable and can better regulate their microclimate. Currently only 2-3 per cent of Europe´s forests can be classified as natural.
• Increasing the diversity of forests, as the more diverse and natural a forest, the more resilient it is to climate change.
• Avoiding multiple stress situations in the forest.
• Reducing fire risk and improve fire management.
• Implementing adequate and effective restoration measures after forests have been damaged by fire and drought. This includes replanting with native, fire-resistant species, for example cork oaks in Portugal rather than pine and eucalyptus.
• Accepting that if trees die in a forest, they should be left as valuable homes for a very wide range of insect, fungus, and bird species. Dead trees in forests add greatly to the forests resilience and biodiversity.
For further information:
Communications Officer, WWF European Forest Programme
Tel: +43 1 48817 217 or +43 676 83 488 217 (mobile)