In a corner in a 7-acre Hampshire wood, I should have noticed that the English oak tree is ruling the forest. At least that was what the owner had in mind when they planted the oak tree, as well as all of its mixed cousins, back in the 1990s.

Unfortunately, the plant is now quite weedy and almost an oddity. The laceration extends from the knee to the top.

At 20 feet, the tree has grown two small limbs. However, the trunk is now dead because it lacks any bark.

‘We’ll have to take this one down next year,’ says forestry expert Colin Corkhill. ‘We might get a few logs out of it but not much else.’

He points out that there are more than 6,000 different life forms resident in an oak tree — lichens, different types of moss, insects galore — and others will take up residence in the dead wood which will be left on the woodland floor. It is a huge waste.

It has nothing to do w/ disease. It isn’t a Sudden Oak Disease case. This previously healthy oak was decimated by the gray squirrel, which is now the most serious threat to British forests. We have now reached the tipping point.

For at the very moment when the Government is urging us to plant more trees — both to save the planet and to celebrate next year’s Platinum Jubilee of the Queen — there has hardly been a less favourable time to do so.

You can clearly see the reason why this wood is so crowded, with identical thickets running up and down each side. You can see why the grey squirrel runs amok, chewing away bark from healthy trees, and then leaving them to die. Colin points out half-a dozen mauled field maples, which are in prime condition, but will be used as firewood soon.

Grey squirrels pose the greatest threat to British foresters at the moment. They eat the bark of trees, leaving them to die. Picture: Grey squirrel perched on a tree

It’s bad enough watching Britain’s ash trees wither from the ash dieback fungus now ravaging our countryside. We can only do so much. The squirrel is an exception to this rule. And it’s not just trees which are paying the price.

This pest kills songbirds, and also pinches nests. Worse still, our native red squirrel, which once roamed the entire country — without chewing trees to death — is now an endangered species, clinging on in pockets of Scotland and places such as the Isle of Wight.

The number of people living in the area is estimated to be around 200,000. Red Squirrel Survival Trust will make an announcement next month, with Red Squirrel Day on January 21.

Its patron, the Prince of Wales, loves the vanishing red so much that he has a squirrel-feeding table in the hallway at Birkhall, his home on the Balmoral estate (where he has also erected ‘Squirrel Crossing’ road signs).

Grey squirrels, on the other hand, are everywhere. The few that arrived from North America in 19 century were now on the verge of reaching three million.

It is larger and stronger than native red. However, it also carries the squirrel pox. This is fatal to both reds and greys.

Grays also love to chew broadleaf bark. This is a bigger problem. The grey chews the bark off broadleaf trees and gets into its phloem-cambium layers, which are the outside plumbing of the tree that delivers nutrients to the trunk.

The tree becomes susceptible to diseases once a squirrel chews off some bark. Once squirrels have eaten their way right round the trunk, the tree’s circulation is effectively cut off, so it dies.

Deer aren’t the only danger to trees. Even younger trees may be damaged by the deer. However, it’s relatively simple to place tubing around young saplings.

The squirrel however waits to eat the tree until it is at least ten or twenty years old.

Robert Hardman visited a woodland near Bentley in Surrey to witness the damage caused by grey squirrels which can be seen clearly on this tree trunk which has been stripped of bark

Robert Hardman went to a forest near Bentley, Surrey, and saw the destruction done by grey squirrels. This tree trunk has had its bark removed.

All of the trees which were damaged by 1987’s terrible storm have become prime target for squirrels.

Although some landowners try to trap and shoot the greys, they are not always successful. While you may be able to kill a few greys at a time, the rest will quickly return from unmanaged woods.

Successive governments have shied away from any tough action for the simple reason that a predominantly urban British public doesn’t like the idea of eradicating what many regard as a harmless, nut-gathering bundle of fluff.

‘When you live in a city and your only exposure to wildlife is a squirrel in a park, you might think it’s cute but you don’t see the damage it does,’ says Colin, a chartered forester who manages thousands of hectares for woodland experts Pryor & Rickett.

We now reach an abrupt halt. In order to achieve our climate change targets, the government has set unrealistic (some may say even hopelessly) ambitious goals for Britain. They want it to plant 75,000 acres every year in this Parliament.

Britain’s foresters say that it is an utterly pointless exercise unless we do something about the grey squirrel, which currently causes an estimated £40 million of damage each year.

The situation is particularly bleak in England since roughly half of the UK’s 12,500 square miles of woodland consists of broadleaf trees (oak, sycamore and so on), most of those are in England and grey squirrels much prefer broadleaf species to the hardy conifers (pine, fir and so on) which proliferate in Scotland.

‘As things stand, we are not going to hit any targets unless we face up to this grey, furry problem,’ says Caroline Ayre, a chartered forester and manager of the English arm of the UK Confederation of Forest Industries, known as Confor.

She has information about several estates in England, which refuse to plant one new broadleaf until the squirrel threat is eliminated.

In short, staff at the Department for Environment, Food & Rural Affairs (Defra) have a simple choice: if we are to plant millions of trees in order to save the planet, we need to eradicate the grey squirrel first.

They are supported by sound economic arguments. For, while forestry is a £2 billion industry employing 70,000 people in the UK, we remain more dependent on imported timber than any other country in the Western world.

The country's forestry is a £2 billion industry employing 70,000 people in the UK yet some areas are refusing to plant broadleaf trees until the grey squirrel threat has been neutralised

The country’s forestry is a £2 billion industry employing 70,000 people in the UK yet some areas are refusing to plant broadleaf trees until the grey squirrel threat has been neutralised

Only China imports more than the £10 billion of wood products which the UK ships in each year.

Although the Government would love to spend billions of dollars on becoming carbon neutral, it is spending less on the squirrel plague than on subsidies for the parliamentary catering service in one month.

In a speech earlier this year, Lord Goldsmith, Defra minister, promised that the government would continue to support research into a squirrel contraceptive program.

The project is driven by a broad coalition of rural interests — from the Woodland Trust to the Duchy of Cornwall — which have all signed up to the UK Squirrel Accord (UKSA).

Five years ago, the Prince of Wales set this up to improve the survival odds of red squirrels. Defra has now funded this scheme to the tune of £300,000.

‘This has demonstrated the Government’s confidence that this is a sound investment,’ says a spokesman.

However, Britain’s foresters say that it is going to take a lot more than an experimental squirrel contraceptive to fight an existential threat to the nation’s trees.

Which is why a separate charity, called the European Squirrel Initiative (ESI), has gone one step further and is now supporting a project which could sort out the grey squirrel problem once and for all — and humanely, too.

The ESI has teamed up with the world-leading Roslin Institute at Edinburgh University — creator of Dolly, the cloned sheep — to pioneer a new technology. Directed inheritance gender biases are possible using gene drive technology.

This skews sexes within a grey squirrel target population, so eventually you have just males. In this case, your population will eventually decline to zero in a matter of years.

New gene drive technology could be used to skew the balance of the sexes in a target grey squirrel population so that you are left with just males so the population simply fades to zero

A new gene drive technology can be used to alter the gender balance in target grey squirrel populations so you have only males and the population fades to nothing

Although it may sound strange, it’s not impossible. To eradicate malaria from the developing world, scientists are currently working on something similar using mosquitoes.

This would only affect the gray, not the red. The grey squirrel plague, which is man-made, would affect the red but not the grey. If it wasn’t for fools like the 11th Duke of Bedford, who thought it would be nice to import a few greys to scamper around his Woburn Abbey estate in Victorian times, then we wouldn’t now be overrun.

‘The research will cost £10 million which is a fraction of the damage inflicted by the grey squirrel in a single year,’ says Norfolk farmer, Richard Coke, who is one of the ESI members driving the new scheme.

The 250 acres of wooded land he owns near Fakenham are a pride of place. They include some of England’s tallest trees.

His grandfather planted them and he claims that most are still standing today due to his meticulous squirrel control.

There are 80 spring-loaded traps that kill immediately.

‘They require a lot of effort and a lot of volunteers because, by law, you have to go round and check a trap every 24 hours,’ he explains. ‘And even after you have taken out a squirrel, there is a newcomer in no time.’

As well as requiring government funding, the ‘gene drive’ scheme will need ministerial support.

These omens look promising. Iain Duncan Smith, a former Tory leader is an avid advocate.

The Government held a consultation earlier in the year on gene editing across British agriculture. Three months ago, Defra Secretary of State George Eustice produced the official response: ‘The UK is already a world leader in genetics and genomics, and we want to foster an environment that encourages innovation in farming.’

He is being urged by the forestry industry to move quickly.

‘Fighting the grey squirrel is like constantly building a sea defence against an ever-rising tide,’ says Stuart Goodall, the chief executive of Confor. ‘We would urge the Government to back this new gene-editing research as a priority. Then we can start building up the British hardwood industry again.’

Professor Bruce Whitelaw of the Roslin Institute, and the man behind the gene-editing project, says he has been ‘encouraged’ by the latest government noises.

He also said that Defra officials have been reviewing the plans. He estimates that squirrels with the required genetic makeup could be tested and regulated in just eight years, with ministerial support. ‘What we need to remember is that this country already has the ideal infrastructure and regulatory framework for this work,’ he says.

The fact that we now import more than 80 per cent of our wood is a pretty embarrassing statistic for the country which passed the first piece of green legislation in history — Henry VIII’s Preservation of Woods Act of 1543.

That ensured there was a sustainable supply of oak to keep the Royal Navy afloat — and it worked. You could even argue that without this, Britain would have never become a seafaring nation. The world wouldn’t have learned English, and Lord Nelson would have never survived a French invasion. Britain was still able to produce hardwoods up until World War II.

In 1945, it was not possible to revive the industry.

If we are going to do so now, we need to sort out the grey squirrel first — and we can save the red along the way.

No one envisages a ‘magic bullet’ solution. An increase in trapping and contraception could help. Others suggest reintroducing the pine marten. This pine marten-like creature, which is stoat-like, was hunted down to extinction because of its fur. It eats squirrels. It will need much more. Professor Whitelaw may have found the solution with his team.

Tudors were right about managing forests. Can it be too optimistic to believe that 21st-century Britain will have a better grasp of forest management?