WORK has begun to remove diseased trees from two woodland areas near Sabden.
Black Hill and Churn Clough Reservoirs have seen a Ramorum infection spread through the woodlands, meaning an estimated 12,000 larch trees in total need to be felled to stop it spreading.
Contractors will start in Black Hill and remove between 300 and 400 tonnes of timber, which should take around a week.
They will then move on to Churn Clough, where they expect to remove the whole larch wood, around 2,000 tons of timber, in six weeks.
The footpath through Churn Clough will be closed and there will be temporary parking restrictions in Stubbins Lane during the work.
Ramorum disease is caused by a fungus-like pathogen and is particularly serious in Japanese larch trees and rhododendron.
The felled areas will be replanted with trees that are native to the area and the infected timber will be chipped and used for poultry bedding or firewood.
Dr John Morgan, head of the Forestry Commission’s Plant Health Service, said: "These new cases are cause for concern because they represent further evidence of the disease spreading to larch.
“We cannot be sure of the full implications of these outbreaks yet. Overall, the number and area of outbreaks on larch that we are finding this year are down on the previous two years.”
“However, these outbreaks in new regions demonstrate that the threat posed by this disease is still serious. "Anyone who suspects they have seen its symptoms should report it to us without delay.”
Coun Tim Ashton, Lancashire County Council cabinet member for highways and transport, said: "This is an important piece of work.”