Bilberry plants at a Staffordshire beauty spot have been infected by a rare fungal disease.
Phytophthora pseudosyringae has killed some plants near Roach End on the Roaches Estate, near Leek. The disease does not harm humans or animals.
People have been asked to help prevent the disease spreading by avoiding contact with the shrubs, although the area remains open to the public.
Managers have been preparing to treat the infected site.
'Difficult to control'
Experts from the Peak District National Park Authority and Natural England are taking advice from scientists at the Food and Environment Research Agency as they work to deal with the disease.
Signs have been put up requesting people to avoid contact with bilberry plants, stay on the main footpaths and keep dogs on short leads.
Richard Campen, director of operations for the Peak District National Park Authority, said this particular fungus had only very recently been confirmed in Britain on bilberry plants.
He said: "It is not harmful to people, wild animals or livestock, even when eaten, but it can kill large areas of bilberry.
"It is tricky because it's a fungus disease and fungal diseases are difficult to control because they can spread quite quickly.
"The worse-case scenario would be that it would remove this plant or reduce the amount of bilberry in the Peak District, which [would] have a knock-on effect for all the insects and animals that are dependent on it."