Sections of a "globally rare habitat" will be deliberately set alight on Dartmoor in an attempt to help endangered bird species.
The legal burning of prime heather moorland in Devon will help create a suitable habitat for species including ring ouzels and skylarks, the national park authority has said.
It will allow fresh heather to grow and provide new nesting sites, it added.
Plots of about 300 sq m (about 3,200 sq ft) will be burnt from Monday.
The moor is home to about 30 breeding pairs of ring ouzels and is the only upland in the south of England where they breed.
Head ranger Rob Steemson said: "The burning will also help skylarks, which are nationally in decline.
"Fire will remove all the old vegetation and allow the nutrients to go back into the soil to encourage fresh growth.
"Within four years, ring ouzels should be nesting in the heather," he added.