WHAT could be the decisive battle for Askham Bog is under way.

The first skirmishes began yesterday between developer Barwood on one side and City of York Council and the Yorkshire Wildlife Trust on the other at the opening of a 12 day public inquiry into Barwood's plans to build more than 500 homes on land at Moor Lane, next to the bog.

Opening the case for the developer, David Manley said there were 'complex arguments' over the potential impact of the development on the bog that would be the subject of expert debate later in the inquiry. But he stressed that 'very special circumstances' existed to justify Barwood's plans.

"York is in the midst of a housing crisis," he said. "In order to meet its housing needs... development will have to occur on a significant scale."

But Stephen Morgan, for the council, warned that if the development went ahead there would be 'very significant harm' to the ancient bog.

And Emma Fenelon, representing the wildlife trust, said the bog was 'irreplaceable'. "So much of the natural word is in peril and now, more than ever before, ancient places like Askham Bog must be protected," she said.

So the battle lines have been drawn. The arguments will rage for the next 11 days at the Citadel on Gillygate. Or possibly for even longer: planning inspector Paul Clark has warned that the inquiry, called after Barwood appealed against the city council's refusal of its planning application, could take longer.

So what is at stake? Nothing less than the future of a unique landscape that has taken shape over countless centuries.

Askham Bog formed on the site of an ancient lake left behind by a retreating glacier 15,000 years ago.

The lake was colonised by sphagnum mosses. Over thousands of years, layer upon layer of moss grew up, eventually forming a dome of peat up to 15 metres thick.

Once, there would have been a lot more peat than there is now. But the Romans began cutting the peat to burn, and by medieval times monks were also using it as fuel, reducing the dome of peat to its present level.

That practice of peat-cutting - which ended something like 300 years ago - actually added to the bog’s richness and diversity.

The result of the action of the glaciers, the gradual growth over millennia of a dome of peat, and the centuries of man-made intervention in the form of peat-cutting, was the evolution over time of an extraordinary mosaic of habitats, including peat bog, ponds, fen meadow, woodland and the remains of drainage ditches, all in one small nature reserve.

More than 300 plant species are to be found there, including the rare royal fern, plus marsh orchids, marsh violet and meadow thistle - not to mention a host of insects, birds, frogs and newts, and small mammals.

In fact, nowhere in Yorkshire is there a greater diversity of plant and animals species than at Askham Bog, according to the Yorkshire Wildlife Trust.

So important is the bog that in 1946 it was bought by Francis Terry and Arnold Rowntree - members of York's two most famous chocolate families - and presented to the newly-formed Yorkshire Naturalists' Trust (now the Yorkshire Wildlife Trust) as a gift. It was the Trust's first nature reserve, and the Trust has managed it ever since.

Following the conclusion of the public inquiry, it will ultimately be up to a government minister (acting on planning inspector Paul Clark's recommendation) to decide whether the Barwood proposals do constitute a threat to the bog - and, if so, whether the proposed new housing justifies that.

Many people in York - and far beyond - have already made up their minds, however.

More than 7,000 people signed a petition against the Barwood plans, Sir David Attenborough himself condemned them, and a Yorkshire Wildlife Trust appeal to raise a 'fighting fund' to contest the public inquiry raised more than £28,000 in short order.

Among those appalled at the prospect of new homes next to the bog is former TV cameraman Keith Massey.

Keith, who lives in Bishopthorpe, has for years enjoyed taking quiet walks around the bog.

"It is such a beautiful, quiet, unspoiled place," he said. "It is so near - in just five minutes you can get away from the hurly burly and be in this lovely, tranquil place: just yourself and nature."

Over the years, he has taken numerous photographs of the bog - including a few from the air using a low-flying drone. And so appalled was he at the prospect of the bog being damaged that he put them together into a 'photo essay' that is effectively a love-letter to the bog.

It is Keith's photographs that have been used on these pages today. They capture the full, lush beauty of this unique nature reserve.

But for now, it is back to the public inquiry...