Around 80 per cent of ash trees in the Netherlands are infected with the fungal disease known as ash dieback, foresters have warned.

Staatsbosbeheer Nederland said the spread of the infection was a ‘disaster for Dutch woodlands’. ‘It’s very sad when you’re in the woods and you see that one in five trees are sick or dying,’ Harrie Hekhuis told the Radio 1 Journaal. ‘Often the roots are affected, which can mean they fall down.’

Ash trees make up around 5 per cent of the country’s tree cover and were planted widely in Flevoland, which has 43% of the Dutch ash population. The next largest concentration is in Groningen, with 12% of the total.

If the infection continues to spread the ash threatens to go the same way as the elm, which was virtually wiped out by Dutch elm disease in the late 20^th century. Elms are now injected with a vaccine but no such protection is available for ash trees.

‘The fungus is so aggressive that trying to combat it is pointless,’ said Hekhuis. ‘All we can do is give healthy specimens that seem to be resistant more space to grow and hope they make it.’