Work is taking place at South Barrule Plantation to remove storm damaged trees.
DEFA expects the work to take several months to complete, with fencing and public notices in place to show any diversions or restrictions.
The department said it's aiming to keep the main forest roads open, but some restrictions will apply at times.
The Viking mountain bike trail will be closed throughout the works.
South Barrule's outdoor activity businesses will operate as normal.
Three freed from crashed vehicle
Firefighters say they freed three people from a vehicle after a crash this afternoon.
Yellow weather warning for icy conditions overnight
Ronaldsway Met Office has issued a weather warning about freezing conditions tomorrow.
MHK wants April's minimum wage rise halved
Onchan MHK Julie Edge will ask Tynwald members to introduce the Island's minimum wage rise in phases when the court sits in January.
Declassified photo shows Russian spy ship off Island's coast
The UK government has declassified photos of a Russian spy ship off the Island's coast last year.
Manx student to climb Kilimanjaro for charity
A local student plans to climb mount Kilimanjaro next year to raise money for charity.
Island could see snow later this week
The Isle of Man could be set for snow in the New Year.
How much are board members paid at the meat plant?
An MHK wants to know how much Isle of Man Meats pays its board members.
Government wants your input on proposed homelessness laws
The government's asking you to share your views on planned laws to help homeless people.
