The spring muirburn season has once again led to controversy with campaigners complaining about the practice, despite it being subject to a strict code.
The burning of coarse heather to encourage new growth benefits hill sheep, but it also helps grouse populations.
This has provoked Revive, a coalition for grouse moor reform.
Revive campaigner Max Wiszniewski said: “Footage we captured recently in the Cairngorms is extremely disturbing, showing vast swathes of heather upland on fire with flames and smoke billowing for miles, all for the single purpose of protecting grouse which will subsequently be shot for entertainment.”
Revive and other campaign groups claim that muirburn is in direct conflict with the European Habitats Directive.
Dr Richard Dixon, director of Friends of the Earth Scotland, added: “There is more carbon locked up in Scotland’s peaty soils than in all the trees and vegetation in the whole of the UK.
“Urgent action is needed to reduce Scottish climate emissions and lock stored carbon into our environment.”
In response, Tim Baynes, of Scottish Land and Estates, said: “Muirburn is the traditional way to manage moorland and has been practised for centuries, resulting in Scotland’s renowned purple heather landscape. Muirburn is strictly regulated and the benefits of it recognised by Government and its agencies, as well as those who manage land.
“The mosaic habitat resulting from muirburn has also given us an extraordinary suite of rare birds and mammals which is the envy of other countries.”
Mr Baynes admitted muirburn could be very visible with the amount of smoke, even from small fires, being deceptive.
The public, however, should not be alarmed by the sight of smoke on the hills when there is a clear code of practice being adhered to.
“Recent research shows careful muirburn has minimal impact on the peat layer below and can actually be beneficial, because the charcoal formed by burning is a stable form of carbon storage, helping to prevent it being released into the atmosphere,” Mr Baynes added.
Muirburn is permitted in Scotland between October 1 and April 15.