Neath Port Talbot Council has been served notice by the Forestry Commission that the fungal disease Phytophthora ramorum has been found in the Larch plantation within the Lower Neath Valley park.
The terms of the notice mean the authority is legally required to take actions to manage the issue and prevent it from spreading. This will entail cutting down and removing all the Larch contained within the Country Park.
Craig Gwladys Country Park will be closed to members of the public for health and safety issues reasons whilst felling operations are ongoing. The public rights of way network in the area will also be temporarily suspended during this time.
The felling programme will aim to ensure as many as possible of the regenerating broadleaf trees are protected, and the Council will be applying for grant aid to replant the felled areas with further native broadleaf trees.
The disease, which is not harmful to humans or animals, has previously lead to a mass felling programme within the Afan Valley.
Council Leader Cllr Ali Thomas said: "Woodland areas are amongst Neath Port Talbot's most important assets so it is vital that they are carefully maintained. Whilst it is sad to see the removal of these trees, it is a necessary step to minimise any further incidences of this disease."
"I would like to thank the public for their patience, understanding and cooperation whilst felling operations are in progress."