Fight to save our mighty oak

3:55pm Friday 22nd August 2008

Comments (0)   Have your say »

Five hundred years ago, North Yorkshire was so heavily wooded that it was said a squirrel could travel from Skipton to Knaresborough without touching the ground. Now, the Yorkshire Dales have the unenviable reputation of being one of the least wooded areas of England.

Those huge forests were felled for the obvious reasons - timber for housing, ship-building and just to keep people warm in much more severe winters than we experience now - and the less obvious, like charcoal burning. But by far the biggest culprit was the humble sheep: thousands of acres were cleared to make way for sheep walks because wool was Britain's most profitable export. Thankfully, it never reached the same intensity as in Scotland, where it led to the Highland Clearances, but it left the land so denuded that the Yorkshire Dales National Park has launched a major project to persuade landowners to plant new woods.

This is a pretty sad story already, but I fear I must report it could get worse. Some of England's finest trees, the mighty oak, the statuesque horse chestnut - provider of our conkers - and the stately beech are all under threat from a lethal combination of imported disease and climate change.

And although these diseases are, so far, mainly restricted to the South of England, horse chestnuts on the Duke of Devonshire's estate at Bolton Abbey have already died from a virus-spread canker which is estimated to have hit two million trees throughout England. Foresters on the estate - one of the few ancient woodlands in the Dales to have survived the depredations of the 18th and early 19th centuries - are keeping an anxious watch on the Laund Oak, a 600-year-old specimen in Strid Wood which is so famous that its acorns have been sent to many different parts of the UK to seed new oak plantations.

The cause for concern here is sudden oak death which, despite its name, can also kill beech trees, which are already weakened by long wet winters and are said by experts to be one of the first likely tree victims of climate change. Sudden oak death - caused by a fungus which blocks a tree's ability to draw up water from its roots - was first recorded on the far west coast of America in California. It arrived in Britain via Cornwall. How it crossed North America and the Atlantic is anyone's guess, but it probably came in on timber imported from America. It has now spread across large areas of southern England and South Wales and is moving steadily north.

Such is the concern at this threat to the oak - the very symbol of English steadfastness - that a team of scientists from Imperial College, London, have been commissioned to come up with, if not a cure, at least a plan to stop its spread.

Unhappily, these scientists have turned back to the last arboreal tragedy which still leaves gaping holes on our landscape, Dutch elm disease, which killed many millions of trees - possibly as many as 20 million - when it galloped through the countryside from the 1970s onwards.

Dr Clive Potter, one of the researchers leading the study at Imperial College, explains why learning lessons from the past is important. "We are looking back over archives, maps and reports from the 70s which haven't been studied before.

"We're finding a number of reasons why Dutch elm disease had such a dramatic impact on our countryside, from the sudden emergence of a new, highly virulent pathogen that the authorities weren't prepared for, to complications in deciding who was responsible for containing it and low public awareness of the disease in its early stages.

"Unfortunately, by the time the public became interested in saving the elms, it was too late for most of them."

I hate to join the doom and gloom brigade when it comes to discussing the future of our countryside, but that last sentence sends a chill down my spine. If the oak and the beech join the elm in the rural graveyard, only ghosts will stride our landscape.

Let's hope the boffins can come up with some answers before the Laund Oak and Strid Wood are under full frontal attack.