What the experts say

These publications are the standard best practice guides relating to urban tree design and management, and they are widely recognised throughout the landscape and arboricultural industries. Click on the cover to download the PDF (note: files are between 2.8 and 21.4MB)

“Trees in Towns II, Britt and Johnston (2008)“TDAG: Trees in the Townscape (2012)“TDAG: Trees in Hard Landscapes (2014)


In January 2017 Jeremy Barrell (BSc FArborA DipArb CBiol FICFor FRICS) appeared on ‘The One Show’ defending Sheffield’s healthy highway trees.

Jeremy followed this up with an article in February 2017: Tree benefits; the missing part of the street tree cost benefit analysis equation’, published by the Institute of Chartered Foresters. In it he says:

“Sheffield was widely hailed as one of Europe’s greenest cities, but it is rapidly gaining an international reputation as the place where they are felling street trees on an industrial scale. Local democracy seems to be unravelling before an international audience as the wishes of local communities are ignored and healthy trees with decades of life left in them are felled causing significant loss of tree benefits. It is a political problem and it will be for the politicians to find a solution, with issues way beyond the remit for tree experts to resolve. However, in the melee for the high ground, tree management principles are being misapplied as Sheffield City Council clamours to justify its actions, and that certainly is a matter where tree professionals can assert authority.”

The graph at the end of the article was included in Jeremy’s presentation to the 2017 STAG conference. It illustrates the actual lifespan of street trees and is included in our tree life expectancy leaflet. At the conference, Jeremy summed up the entire situation with the phrase: “PFI contracts don’t work for trees.”


Professor Ian Rotherham, of the Department of the Natural and Built Environment at Sheffield Hallam University, has been an advocate for the city’s street trees from early on in the campaign. In a statement given recently to STAG he said:

“I have described the current situation as ‘The Sheffield Trees debacle’ and as ‘an avoidable crisis‘. Indeed, before the present situation unfolded, having had concerns raised by local people, I went to meet with Amey to see if ways could be found to make this a more positive, beneficial and inclusive process for Sheffield communities and the Sheffield environment. I came away from the meeting with platitudes, excuses, and intransigence in terms of any review of position or process. Blithely unaware of any of the city’s commitments or polices on ecology, community or the environment, it was clear that both Amey and SCC were determined to press ahead with a thoroughly damaging, expensive and undemocratic assault on the city’s highway trees. The scale of this misapplication of funds and resources becomes more apparent with the misuse of the original consultant’s SCC-commissioned review – which recommended a maximum of 500 trees to be in need of removal, when after only 3 years or so, over 5,000 had been felled. This represents a catastrophic undermining of local environmental democracy, of local sustainability, and of planning for climate mitigation, for biodiversity and for community health and welfare – and is on an unprecedented scale.”

Read Ian Rotherham’s excellent article: ‘The city that hates trees’ standing up to the Sheffield street-tree slaughter in ECOS 39(3) .


The University of Sheffield’s Landscape Department have issued a statement regarding the future of the city’s urban woodland on their blog.  It includes the following:

“We believe that a stronger urban tree strategy for Sheffield can be developed organically with the good will of Sheffield residents when it is accompanied by a well-rounded and open assessment of the benefits and disadvantages of urban trees and supported by the latest research in urban forestry and landscape architecture.”

The draft version of SCC’s Trees and Woodlands Strategy 2016-2030 was read by landscape department staff, and suggestions were made, however this consultation document remains unfinished.


“Trees for Cities

In March 2017, Trees for Cities, a leading international tree charity, expressed concern about SCC’s street tree policy.

“Trees for Cities is deeply concerned about the felling of street trees as part of Sheffield City Council’s Streets Ahead programme. Whilst Trees for Cities accepts that in all urban contexts there will be a small percentage of dead, dying, diseased or dangerous trees that will need to be removed, it believes there to be irrefutable evidence that a number of healthy mature trees have been felled where other options were available. Trees for Cities calls for Sheffield City Council and Amey to immediately suspend the tree felling programme until an agreed way forward is reached amongst all key stakeholders.

At the very ethos of Trees for Cities is a belief that no healthy street tree should be destroyed before the end of its natural life, apart for in exceptional circumstances. Street trees have an irreplaceable aesthetic value that help make our cities liveable. They provide essential ecosystem services such as cleaning and cooling of the air, absorption of greenhouse gases and the reduction of flood risk. They are associated with a number of social health benefits. They create a connection with nature and the seasons. They act as a habitat for wildlife and protected species. It can take up to 100 years for a tree to reach maturity and provide its full social and environmental benefits, and hence the removal of any tree should be deemed as a last resort and alternatives such as engineering solutions should always be adopted where possible. It is absolutely unacceptable for any tree to be removed for economic gain.

Trees for Cities has planted trees in Sheffield over the past ten years undertaking projects in schools and creating urban woodlands and community orchards. Over this period we have planted over 25,000 trees. To deliver these projects, we have worked closely with the Community Forestry Team of Sheffield City Council’s Parks Countryside Service and we have always received great support. It is with deep regret, however, that whilst these practices continue Trees for Cities is unable to develop further projects on council land. For the sake of the city’s trees, inhabitants and wildlife, we implore the decision-makers in the City Council, Amey and local politicians to urgently seek an acceptable resolution to this situation.”


‘Sheffield Street Trees’ was compiled by Ian Dalton, Tree Officer for the London Borough of Bromley, after he visited the city in March 2017. Ian is an experienced arborist qualified to Dip ArbLevel 4 who has been employed in the arboriculture industry for 16 years. He concludes that good arboricultural practices are not being followed, standard engineering solutions are not being employed and that many of Sheffield’s trees are being felled unnecessarily.

Ian has since compiled the insightful CAVAT valuation report on Street Trees in Sheffield (note: 8MB download).  The data was gathered from across the city by a keen group of ‘citizen scientists’ who carefully measured each threatened tree. The results speak for themselves: by the end of 2017 SCC will have destroyed £60 million’s worth of healthy street trees.


‘Regarding trees in Nether Edge, Sheffield’ is a report written by Peter Townsend, BSc CEng MICE, a highway engineer with many years experience delivering similar Local Authority contracts to the current ‘Streets Ahead’ programme.

Peter, a Sheffield resident, has had plenty of opportunities to observe the city’s street trees, and he believes many of those that are currently condemned could be retained.


“Well Managed Highway InfrastructureIn October 2016 the UK Roads Liaison Group published the Department for Transport commissioned document ‘Well-managed highway infrastructure: a code’.  It contains guidance that is particularly relevant considering the Council’s rigid attitude towards accommodating tree roots within pavement surfaces. Under Section B.5.46 it states:  

‘…extensive root growth from larger trees can cause significant damage to the surface of footways, particularly in urban areas. A risk assessment should therefore be undertaken with specialist arboricultural advice on the most appropriate course of action, if possible to avoid harm to the tree. In these circumstances, it may be difficult for authorities to reconcile their responsibility for surface regularity, with wider environmental considerations and a reduced level of regularity may be acceptable’.


Steve Frazer, CMLI, is Principal Landscape Architect at Enzygo Ltd, Sheffield.  He has written a piece on Sheffield’s street trees for the Landscape Institute blog, in which he concludes:

“The Streets Ahead project is truthfully a highway project focused upon delivering smooth tarmac, despite the environmental claims otherwise. It was likely formed with the best of intentions to solve a single perceived problem, that of potholes, but the objectives and mechanisms for delivery derive from a narrow perspective, that of highway engineers and councillors. I am certainly not criticising highway engineers, but I am emphatically criticising silo working, as it can offer only a narrow view for what is important, does not embrace collaboration and therefore does not exploit design opportunity.

For Sheffield to have achieved a better outcome, I believe they needed a bolder vision, which appreciated the potential of a street in its broadest sense, recognised and pursued by a multidisciplinary team that understood the existing assets. And of course, these proposals should have been developed alongside the citizens of Sheffield to ensure that the project reflected community interests, promoting real engagement and ownership. These feel like relatively modest aspirations given the scale of the project.

However, the reality is that Sheffield feels like a big opportunity missed, with the Streets Ahead programme an ironic title falling woefully short of its potential. As a consequence, the public will has been frustrated, the council have suffered tremendous damage to their reputation and the city will bear a poorer environment. Perhaps a tough lesson on narrow ambitions meted out to Sheffield, but hopefully learnt by others.”


Rootstock landscape consultancy have written a thorough analysis of Amey’s landscape and impact assessment methods, which provided the foundation for Sheffield’s tree replacement programme. Amey’s approach falls short of expected industry standards.  For example, assessments were carried out remotely using mapping data and if site visits were made then no information about them was recorded.  The article goes on to discuss other weaknesses in Amey’s approach and how it might be avoided in future.


“Well Managed Highway Infrastructure

In August 2017, the Sheffield Society of Architects was moved to write to Cllr. Julie Dore about the fate of the city’s street trees.  Here is the letter reproduced in full:

“We are becoming increasingly concerned about the negative effects that the Streets Ahead contract is having on Sheffield’s built and natural environment, including the impact on the ability of the city’s trees to reduce pollution, provide habitats for wildlife, provide shade, and amenity value.

As built environment professionals, we often work closely with landscape architects, urban designers and other specialists, and understand how important landscaping is to residential areas, particularly in the urban environment.

As cities become denser and more crowded the effect of trees and other landscaping is critical to the physical and mental wellbeing of the inhabitants.  The overwhelming evidence of the positive social and environmental impact of urban trees, and particularly street trees, is well documented in numerous publications and reports, including those by Trees for Cities, The Forestry Commission and Natural England.

We understand and accept reasons for felling badly damaged or diseased trees, but we do not believe there are acceptable reasons why trees that are healthy and have many decades of life left are being felled now. Problems with ground surfaces around tree roots can easily be dealt with by the correct technical detailing of the surrounding build-up.  Typical technical solutions have been drawn up and sent to the Working Party – although similar solutions are already outlined by the Council in the Streets Ahead 5 Year Tree Management Strategy, which includes engineering and alternative options that should be considered in order to retain trees (section 3.2, page 11). The Strategy also confirms that these proposals would require ‘no additional funding’ from the council. As these solutions are set out in Streets Ahead’s own document, they must fall within the contract between the Council and Amey and therefore can and should be implemented in preference of felling.

Nationally recognised arborists have reviewed the condition of the threatened trees and have confirmed that were the solutions outlined above to be implemented, the majority of the threatened trees could be retained.

Whilst we recognise that felled trees are to be replaced, we are of the opinion that although the chosen species may reduce issues such as sap drip, even when mature the replacement trees will not have the same stature, environmental benefits or aesthetic appeal as the originals, particularly where they are sited well away from the current location. A better compromise is possible and must be found.

ARUP landscape architects report, ‘The benefits of large species trees in urban landscapes: a costing, design and management guide,’ shows that the annual net benefit of planting large species of trees is 92% greater than for small species. It also outlined the financial, social and environmental benefits of large tree species, and how they be successfully retained and planted in urban environments. Rather than remove mature trees and replace with small-species saplings, it of course makes the most financial, social and environmental sense to retain large mature trees wherever possible.

The 2011 report, ‘Torbay’s Urban Forest: Assessing Urban Forest Effects and Values’, concluded that the structural asset of their trees was worth a remarkable £280millon. Sheffield is well known as being a green, leafy city and its trees will also undoubtedly have a significant financial value.

Whilst we understand that street trees make up a small percentage of Sheffield’s overall tree cover, we recognise the special importance of large street trees, and are therefore increasingly worried about the negative impact of the current implementation of the Streets Ahead contract. Notwithstanding the disturbing content of the tree works, the often bizarre phasing of works to trees and neighbouring roads/footpaths, and numerous examples of potential health and safety breaches also lead us to conclude the contract is not being delivered in a manner deserving of this great city.  We therefore urge the council to review the contract and act in the strongest terms in the interest of the city (and beyond) to ensure street works are administered in a safe, neighbourly manner, including the cessation of tree felling and preference for retention.”


The city’s disabled residents are often invoked when discussing the impact of trees on Sheffield’s pavements.  STAG has received a message of support from the Sheffield branch of Disabled People Against Cuts.

“DPAC Sheffield send solidarity to protesters campaigning against the felling of healthy trees throughout Sheffield.

We were dismayed to hear that some people have tried to use us, disabled community, as scapegoats for tree felling citing space needed for wheel chairs and mobility scooters.

We thank those people to remember that have our own voices, and that we shall use them to defend existing services and green spaces; not to destroy them!

Each tree should be treated on a case by case basis with only irrefutable evidence from expert professionals being used to validate felling healthy trees.

Two mature trees will create enough oxygen in a year for a family of four to breathe, yet thousands of healthy trees are marked for the chop.

With increased traffic and business growth in Sheffield we need them to filter the air in built up areas.

Currently the Council are essentially charging us for poorer air quality and for the city’s children to grow up in a concrete jungle.

The people destroying our trees have the same mentality as those who are destroying disabled people’s lives. The state seeks to declare people who are not fit for work, ‘fit for work’. Equally perversely, the state seeks to condemn healthy trees as not fit to live. And in doing so they make all our lives poorer. Except their own lives of course. Because both of these ridiculous and gross situations are caused by people who wish to enrich themselves financially and override democracy.

What is happening to Sheffield’s trees and to disabled people are proof that there is no democracy in decisions that cause the destruction of our city’s assets due to profit, as is also happening with the work capability assessment and treatment of disabled people in the UK.

We will stand by your fight to the end.”

Let’s Dance For the Trees


Buy tickets for the Let’s Dance for the Trees event taking place on 8th December from 8 to 11pm.

Crowdfunder: street trees legal fund

We are currently collecting to support the small number of campaigners who are facing court costs after cases brought by Sheffield City Council.

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