Was the Sycamore Gap tree worth what they said?

The Sycamore Gap tree was a landmark of Northumberland and northern England

When the world-famous Sycamore Gap tree was illegally felled two years ago, amidst the widespread rage the issue arose of how much the tree was actually worth. The simple question was not so easy to answer and some tree experts are still not completely happy with the final number.

Daniel Graham and Adam Carruthers saw it as something worth destroying.

In the depths of that stormy September night two years ago, the pair filmed the moment they felled the world-famous tree and took a wedge away as a trophy.

In the aftermath, as grief and outrage spread, the issue of the tree's financial value - not just its emotional one - became a hotly debated topic.

Early on, prosecutors put the tree's value at £622,191, later reducing this to £450,000 which the defence team argued was still too high.

Once everyone agreed it was at least more than the £5,000 criminal damage threshold, which determined the sentence the pair could receive, the actual value became a moot point.

And yet, for some of us, the need to know how much the tree was really worth remained something we could not quite shake off.

The system used to calculate the tree's value was developed by arboriculturist Christopher Neilan and the London Tree Officers Association in 2008.

Mr Neilan says this was "undoubtedly" the highest profile use of the Capital Asset Value for Amenity Trees (CAVAT) process they had devised.

Christopher Neilan wants experts to "by and large" agree on tree values

The system looks at several features of a tree including the diameter of its trunk, its remaining life expectancy and the amount of foliage it has.

Through multiple freedom of information requests, the BBC has obtained the Sycamore Gap tree CAVAT report produced by the Forestry Commission and given to the police as evidence.

This said, prior to its felling, the tree was in good health and had a remaining life expectancy of more than 100 years.

Research conducted since the tree's demise suggests it had been at least 100 to 120 years old.

Mr Neilan has reviewed the report and says he believes the commission overinflated the tree's monetary value.

"I find it very upsetting," he says.

"At a fairly early stage, I did try and get in touch with the people doing this to offer help to get it right. But I found it difficult to work out who to talk to."

The Forestry Commission declined to respond to the suggestion it had not used the CAVAT system as intended, saying it does not comment "on evidence put before a court".

But, in the end, the tree's monetary value was never presented in front of a jury.

Forensic investigators examined the remains of the Sycamore Gap tree

Mr Neilan's biggest issue with the commission's calculation is the way it worked out the tree's Community Tree Index (CTI) factor.

This element of CAVAT was devised so trees in more populous areas, which could be enjoyed by more people, would score higher than those in remote areas where fewer people would interact with them, he says.

All areas of the UK have published CTI scores based on population density and, as Sycamore Gap was in Northumberland which is not densely populated, it should have been given the lowest possible score.

Mr Neilan acknowledges the tree was a major tourist destination and the number of visitors would affect a CAVAT valuation, but says not to the extent that it did in the Forestry Commission's evaluation.

However, the commission gave the tree the highest possible CTI score because it said more than 52,000 people visited the tree each year and more than 488,000 people were estimated to see it via "drive-by viewings".

The tree was a much-loved landmark before it was illegally felled in September 2023

An arboricultural consultant based in Kent, Dr Jon Heuch, says giving the tree the highest possible CTI score had been a "gross distortion" of CAVAT that resulted in its final value being put at £458,139 - more than double what he says it should be.

Speculation among fellow tree experts was that the initial £622,191 valuation came from incorrect measuring of the trunk's diameter - at the base, rather than higher up, resulting in too large a number, he says.

"Word gets around," he adds.

The tree was planted by Hadrian's Wall in the 1800s

The difficulty in calculating the tree's value lay in the fact it was "unique" and well beyond the usual parameters these valuation systems were typically used for, Dr Heuch says.

He believes this was compounded by a public desire for a "big number".

"They're almost reassured by a big number," he says.

There was also a lot of "emotion tied up" with Sycamore Gap and its depiction in films such as the Kevin Costner epic Robin Hood - Prince of Thieves, which meant the conversation was about more than just the tree itself.

"We're talking about the valuing of something else and I can't really put that into words as to what that is," he says.

"Robin Hood in this film comes from France to Nottingham via Northumberland.

"It's a complete fiction but people have warmed to that fiction.

"How can you put a monetary value on that sort of emotional situation?"

Jon Heuch said films added to the "emotion" felt in relation to the tree

Mr Neilan says his team developed CAVAT so that, following their methodology, consistency would be achieved regardless of subjectivity and emotion and, "by and large", experts would agree.

"I was determined that the differences in the score would reflect the relative differences in opinion about the tree," he says.

He wanted to devise a system that felt "trustworthy" and feels the dispute over the tree's cost has undermined it.

"It's an enormous shame to have left the impression that, if you use CAVAT, you can get enormously different results," he says.