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Scientists from the University of Copenhagen are trying to find as many of the precious resistant trees as possible — likened to searching for needles in a haystack - in the hope that seeds and grafts can be gathered from them to produce nurseries of healthy stock.

One day saplings from such nurseries will be planted to replace the dying trees.

Which makes it deeply unsettling to walk through rustling leaves into a patch of 40 or so dead and dying trunks, most upright, some toppled; the diseased remains of what was only three years ago the biggest stand of healthy ash in a forest of beech and oak.

Scientists now think the disease is spread by fungus on dead leaves which lie on the ground all winter, then produce spores between July and September which are carried by the wind.

The disease probably travels through the countryside at about 20 miles per year.

“Children sing songs about the ash in school,” Mrs Olrik says.

“And according to the old stories, when the ash trees die, chaos follows.” The effect on wildlife is expected to be serious, and in some cases disastrous.