It is an all-too familiar scene of environmental destruction. Deep in a forest, heavy machinery has felled a giant swath of trees to leave bare scrubland and a handful of stumps as forlorn memorials. The timber has long gone and cattle now pick their way across the clearing.

But the scene of this environmental vandalism is not Indonesia or the Amazon; it is affluent Surrey. And those responsible are not illegal loggers, but one of Britain's largest and most influential conservation groups. If it has its way, a forest near you could be next for the chop.

"Scots pine, Corsican pine, Japanese larch. There are clues in the names. These trees are not native to southern England," says Mike Coates, a project manager with the Royal Society for the Protection of Birds.

In a controversial move, the RSPB has set its sights on England's non-native woodlands, which it wants to demolish to find space to restore a different type of English habitat, the open and rugged heathland immortalised in the novels of Thomas Hardy. Dominated by heather and scrubby plants, such heathland is an increasingly rare sight in England, and so is the wildlife that relies upon it.

Coates says: "Woodland is very common compared with heathland. But re-creating heathland is so much better for wildlife than a conifer plantation. Lots of the birds that live in the conifer forests are common and can survive elsewhere. Heathland stuff needs heathland, and much of it is very rare."

Restoring heathland will help birds such as the nightjar and woodlark, he said, as well as rare insects, plants and reptiles, including the elusive adder, Britain's only venomous snake. The RSPB has made a start on its Farnham Heath reserve in Surrey, where it has cleared some 60 hectares (150 acres) of conifer forest to make way for heathland, but it has bigger plans. Ministers are poised to decide whether the Farnham Heath experiment should be repeated nationwide, across tens of thousands of hectares of government land run by the Forestry Commission.

The RSPB is lobbying hard that it should be. It wants the government to double the 55,000 hectares (135,000 acres) of lowland heathland in England by chopping down the non-native conifers that stand in the way.

Nick Phillips, RSPB's biodiversity policy officer, says it is a "once in a generation" opportunity to revive heathland on a large scale. Many of the trees in question were planted after the second world war, on cleared heathland, and are due to be harvested soon. The old heather seeds are still in the ground, he says, but will not survive much longer.

"All you've got to do is get the trees off to expose the buried heather seeds, get some sunlight and water and, bingo, in five years you've got a heathland. If you replant [conifers] after the trees are harvested, you've blown it. You can't restore heathland without it being much more difficult and time consuming."

At a time of increased awareness of climate change and the merits of protecting forests to reduce emissions, it strikes some, including the Green party, as a strange move to chop down trees in the name of protecting the natural world. The government's own figures suggest such a large-scale clearance could increase Britain's carbon emissions by up to 0.1%.

Stuart Goodall, chief executive of the Confederation of Forest Industries, calls the idea "absolutely crazy". He adds: "The government is highlighting the importance of combating climate change and planting trees to lock up carbon, and here we have a proposal to chop trees down, release carbon and lose jobs, all for an environmental benefit that you can get from better management of existing heathland. It just doesn't add up."

British companies have come to rely on the regular supply of softwood from the conifer forests, he says, which is used for construction, furniture and wood products such as fencing and pallets. "The forestry sector is small and we can struggle to get our voice heard. We are an easy target for the RSPB to pick on."

He adds: "It is a fallacy to think that certain types of trees have no biodiversity benefit. It's just that conservation bodies don't like them. But plenty of local people like walking in these woods."

Coates is unrepentant. "It should be the right tree in the right place. A field of barley is a field of grass, but it's not a meadow; it's a crop. In the same way, these are areas of land dominated by trees, but they are not woods, they are crops."

Heathland restoration will help Britain to adapt to global warming, he says, by providing habitats for species such as the Dartford warbler to spread north with rising temperatures.

At the centre of the debate is the Forestry Commission, which is drawing up several policy options for ministers to choose from this autumn on the back of a summer consultation exercise.

Dominic Driver, of the commission, says that between 6,000 and 30,000 hectares (15,000 and 75,000 acres) of conifer forest are likely to be removed over the next 10 to 15 years. Privately-owned forests could also be converted, with the help of government grants. Driver says lost trees will be replaced somehow. "We can't have deforestation in the UK."