Thousands of Courier Country trees are being checked for signs of a deadly disease.
An alert was raised after four cases of phytophthora ramorum were found in larch trees in Tayside. The disease attacks the wood, killing the trees.
Three of the cases are in forests on private land near Forfar and Dundee, while the fourth is near Perth.
Officials at Forestry Commission Scotland (FCS) have declined to reveal the exact locations involved but are to order the destruction of any larch within 250 metres of any infected tree.
Perth and Kinross Council has confirmed officers are looking at all trees in their jurisdiction for signs of the disease.
A spokeswoman said: “Our community greenspace staff will be monitoring our public parks and green spaces in Perth and Kinross for any signs of this disease, in conjunction with Forestry Commission Scotland staff.
“We would also support the advice from FCS for anyone visiting or working in woodland to help prevent any spread of the disease.”
Phytophthora ramorum has already devastated forests on the west coast of Scotland, but is less common in eastern regions.
Dr Anna Brown, Forestry Commission Scotland’s head of tree health, said: “Phytophthora ramorum can attack a wide range of trees and shrubs but has had a particularly devastating impact on larch in Dumfries and Galloway, as well as at a number of other sites in west Scotland.
“Although the disease is not unknown in the east of the country, it is considerably less common there due to the generally drier conditions.
“It is vital that we remain vigilant in these areas and do all we can to prevent the disease from reaching other nearby sites.”
As part of its Keep it Clean campaign, FCS is advising forest visitors to clean any dirt and mud from boots, bike wheels, paws and hooves before visiting a woodland.