BBC News Isle of Man by Ellan Vannin 14 January 2014
Aerial surveys by the Forestry Commission in 2011 showed the affected areas (photo).
Work to fell hundreds of thousands of infected larch trees in the Isle of Man will begin this week after an "explosion" of a deadly tree disease.
According to the Manx government about 50% of the island's larch population is currently infected by Phytophthora ramorum.
Forester Jason Bolt said the essential work will have a "huge impact on the island's landscape".
The Forestry Division plans to fell 450 hectares (1,111 acres) of larch.
Senior forester John Walmsley said the disease, first detected on the island in 2010, had "exploded" since March.
In July, a survey by the Manx Forestry Directorate showed a "considerable spread" of the disease in the north of the island.
Since then it has spread to the south, east and west.
Mr Bolt said: "Larch makes up around 20% of our forests and in the short term it will have a major impact."
Environment Minister Phil Gawne said it was a "vital step" for which "quick action was needed".