Rangers at Hardcastle Crags are on the lookout for the first signs of the disease that is threatening ash trees across Europe.
Chalara has been making its way across the continent and was recently found to have affected trees in Huddersfield putting staff at the National Trust park on alert.
Judith Patrick, at Hardcastle Crags, said: “We are surveying them to make sure we don’t have any problems. We are concerned as it is an issue and something that we’ve seen spreading across Europe on a daily basis.
“The ash trees were a species of tree introduced here in the 1800s so they only make up about two per cent of our trees.”
Ed Brightman, ranger, said: “We’ve been going round and plotting where we have our ash trees. Marking the trees and hope that they will be ok.
“If there is anything that’s been spread it will be on the leaves and in the leaf litter.
“It’s not a natural site for ash, some were planted over 100 years ago. Those that are planted are mature specimens so it would be sad to see them go.”
Ian Wright, plant health adviser at The National Trust, said he is concerned about the amount of infection but as we enter winter the infection rate will slow down but also makes it harder to spot infected trees.
He said: “There is no sporination at the minute which makes it harder for the infection to spread.
“We must use this period between now and June to come up with any credible ways forward if there are any.
“When the foliage comes through it will make it far easier to spot infected trees.”
Ash trees make up between five and 10 per cent of the total tree matrix in the country.