Uncovering the facts and myths behind trees debate

Sheffield street tree debate: View from Meersbrook Park
Sheffield street tree debate: View from Meersbrook Park

Like many of us, Jan Turner lives next to a tree. “On a hot day you’re desperate to walk onto this road because it’s cool and beautiful,” she said. “You see squirrels and goldfinches, and this week I saw a woodpecker just there, level with my shoulder.”

One morning, she found her street trees were coated in silver. “They were shining, like something out of a fairy tale.” The trees, by Meersbrook Park, had been colonised by thousands of web-spinning spider mites.

Jan, secretary of Gleadless Valley Wildlife Trust, uncovers all kinds of insects in her lime bark, including a recent record of the first Copper Ermel moth in Yorkshire. One night she encountered a baby tawny owl on her window sill, as its mother called from the tree. “It’s astonishing to think all this is going on just outside your front door,” she said.

But as contemporary tree campaigners know, such encounters are irrelevant to the imperatives of private finance initiated decision-making.

For this reason, veteran environmentalist and blogger Professor Ian Rotherham likes to designate Sheffield’s two million trees as ‘ecosystem service providers.’

“These trees in Meersbrook are a fantastic resource, they enhance people’s lives, make people happier, fitter and healthier, and save the government money because people are in better health and better mental health because of them.”

Ian, professor of environmental geography at Sheffield Hallam University, added that street trees help to mitigate flooding, remove traffic pollution, and reduce high summer temperatures on tree-lined roads by well over five degrees, and thus save lives. They’re also ‘green arteries’ for people and wildlife, he said, and should form part of the city’s nature conservation strategy. “But none of these things appear to be taken into account in a strategic, co-ordinated scientifically valid way, so all the decision making is woefully ignorant, based on short-termism and the false economics of the public private partnership. It’s deeply unsatisfactory.”

As it stands, trees like the Rustlings Road Twelve (a row of limes near Endcliffe Park recently given a temporary stay of execution) appear to have no monetised climate, health, biodiversity or property value benefits which might counter the official ‘dangerous, dead, dying, diseased, damaging or discriminating‘ determinants which highway contractors use to decide if street trees stay or go.

It seems the original contract with Amey did not properly assess how our glossy Streets Ahead programme could accommodate Sheffield’s Victorian street trees. The idea that many are dying is disputed by Prof Rotherham, who said: “Our trees have had a stressful time, with many years of horrific air pollution, but now you’d expect these trees to be responding to an improved urban climate. The limes in Meersbrook are middle aged, they’re not dead or dying.”

One view is that century-old street trees could be managed as they present themselves: the dangerous, dead and dying to be replaced so future generations have mature tree cover, while others could be carefully looked after as they grow older, which would have a cost, to someone. Since the council has ever-dwindling resources, might the residents of tree-lined streets wish to pay a levy to help their trees survive through middle age?

Campaigners hope the new ‘tree forum‘ will lead to an official Sheffield tree strategy. “Our urban forest has been here for over 150 years, so why try to rush through a decision in six months?” said resident and woodland expert Ted Talbot.

One urgent option, say the arboricultural lobby, should be to redraw the existing highway maintenance contract to address street trees more positively, rather than the current policy based on six ways to decide if a tree gets the chop. And if, under the current rulebook, a tree’s impact on ‘kerbstone alignment’ really is a red card offence for ecosystem service providers like Jan Turner’s lime, why not also rethink the layout of residential streets, since the long-term plan is to design down traffic speeds on such roads?

Sheffield proudly states it has more trees per resident than any other city in Europe: we have three trees and a sapling each. Landscape historian Dr Paul Ardron said the city’s avenues of mature street trees were planted as a celebration of civic pride, to gentrify the streets. But just like owls, happiness and spider mites, civic pride does not yet appear on highway maintenance spreadsheets.