Woodland managers with larch trees and rhododendrons across the area have been urged to be on their guard after a new disease was found at Glen Dye, south of Banchory.
The outbreak is of concern because the fungus-like pathogen Phytophthora ramorum (‘Ramorum’) which causes the disease has so far been confined to the west coast of Scotland where the wetter climatic conditions are more suited to it.
The Glen Dye site consists of four symptomatic larch trees adjacent to a public road but there are also subtle signs of the disease adjacent to these trees.
A spokesman for the Fasque and Glendye Estate, who owns the woodland in question said: “Once it had been confirmed that the trees had the disease, we decided to take swift action to prevent it spreading. We arranged for the removal of all the Larch trees within a 100m radius of the site the following day, in line with Forestry Commission advice.
“Biosecurity has been of paramount importance to contain the disease and all vehicles have been washed down with the appropriate chemicals to prevent its spread. We will be working with the Forestry Commission over the coming months to do what we can to ensure that this remains an isolated case.”
P. ramorum is causing extensive damage and mortality to larch trees and other plants across the Uk - and in Scotland there are now 137 larch sites with confirmed infections, extending to some 420ha (out of a total larch area of 65,000ha), almost all of which have been on Japanese larch. About 75% by area of the outbreaks are in Galloway.
Hugh Clayden, Tree Health Policy Adviser, for Forestry Commission Scotland, said: “This outbreak is in a part of the country that is considered to be less climatically suitable for Ramorum - and which is also far from the nearest infected larch crops.
“We are currently investigating how the disease arrived at this location but one possibility is through unintentional transfer on vehicles using the public road.
“We will be extending our aerial surveillance to include Glen Dye and other high risk locations in east Scotland and I would urge all land and woodland managers everywhere to remain vigilant for Ramorum disease on their larch and to seek advice as soon as anything suspicious comes to light.”