Tree replacement and carbon neutrality

The UK aims to be carbon neutral by 2050. Bristol is more ambitious and aims to reach that goal in 2030. Both are massive challenges in which trees have been enrolled to play their part in mitigating the carbon dioxide (CO2) created by human activity.

Background

There are plans for extensive tree-planting.  The government pledged to plant 30 million trees a year, nationally. This a huge challenge partly because seedlings and land has to be found for these trees. However even when planted, these trees will take a long time to grow and extract CO2 from the air.  We in Bristol Tree Forum are concerned that not enough attention is given to the role of existing mature trees.  

Trees grow and add to their mass each year. Most of this mass is in the form of cellulose and lignin and about 50% of those organic compounds is carbon, obtained through photosynthesis using the energy of sunlight and CO2 from the atmosphere.  The rate at which mass is accumulated increases with age so whilst a 10 year old tree might put on a few kilograms a year, a 50 year old tree might add 50 kg.  So the older the tree the better for CO2 fixation. However mature trees are constantly under threat – from development for housing and industry, from home owners overshaded by large trees, from councils assessing maintenance costs and risks.

Here in Bristol, the Bristol Tree Replacement Standard (BTRS) is part of local planning regulations and specifies how many replacement trees are needed to be paid for by the developer and planted to mitigate the loss of mature trees. The BTRS is a very welcome and forward-thinking strategy, but is it enough to support the Carbon Neutrality goals? Should BTRS  apply also to council-owned and indeed privately owned trees for which no funded replacements are available?

The Bottom Line

In an attempt to understand how this standard works in practice, we have developed an on-line calculator to explore different scenarios.

Tree CO2 Calculator

The general conclusion from this analysis is stark:  it will take 25 to 40 years before the replacement trees are able to compensate for the loss of the mature tree.

The graph shows the scenario of the replacement of a mature tree such as a Maple with a diameter of 60 cm by the 6 trees as determined by BTRS which are faster growing but shorter lived such as Rowens.

Assuming that the original tree is felled, chipped and used as fuel in a biomass boiler (the practice in Bristol), the carbon stored in the mature tree is returned to the atmosphere within months of felling.  The replacement trees start to grow, but absorb much less carbon than the original mature tree would have done, so they take many years to catch up. In the case shown in the graph, it takes 35 years (ie, to 2055) before the new trees mitigate the loss of the original tree.

Modelling

A model of this scenario needs to take into account:

  • the rate at which different species of tree grow at different ages in different conditions.
  • the estimated mortality of the tree over time.
  • the calculation of a tree’s biomass from its girth for different species.
  • the relationship between the tree’s biomass and the amount of carbon stored.

There is a lot of uncertainly in these relationships, partly because of the paucity of data on urban, as opposed to forest, trees. Urban trees are under threat not only from natural processes and disease, but also from the vagaries of vehicles and humans. Planting sites are often less than optimal and urban trees have no support from the ‘wood wide web’.

The interactive calculator allows the user to vary the parameters of the model using the sliders. This allows the sensitivity of the overall outcome to variation in values to be tested. Different policy choices can also be explored and can be used in a predictive sense to determine the number of replacements needed to achieve a given carbon neutral date.

Summary

Documentation on the website explains the thinking behind the model in more detail, and the sources of data used. The model is still under development, in particular to make it easier to select conditions for different species and situations, and to improve the quality of the model itself. The research literature is extensive but often of limited applicability to urban conditions.

We would be grateful to receive additional or better sources of this information, and indeed any comments on the model itself at co2@bristoltrees.space.

Chris Wallace, Bristol Tree Forum

In Defence of Dead Wood

It was once believed that when a tree died, it was no longer of use. For decades, we have actively removed trees at the first signs of rot or fungal attack, felling them at the base and removing all evidence of their existence…

Our guest editor, Nick Gates, Naturalist, writes

Storm damaged trees are hastily sectioned for firewood or bio-fuel. Sometimes, we replace them with a new, younger version of themselves. It was thought that this in turn kept other trees healthy, and that the wider environment benefited as a result.

The fall of a tree opens up new opportunities…

But nothing is further from the truth. By removing this deadwood, we are stripping out a most vital layer of the natural world. Because when a tree dies, it isn’t actually dead.

As a tree grows, its core begins to die. Have you ever looked at a majestic old oak, its core completely hollowed out, and wondered how on earth it was still producing green leaves and fresh shoots? The reason is that only the outer layers of the wood, just below the bark, are alive. They transport all the water and nutrients that a tree needs to survive. Simultaneously, under the soil, a massive network of fungi around its roots help the tree collect all of the vital nutrients and minerals it needs. As the tree grows, the wood core, the growth rings left behind and superseded from previous season, slowly dies.

Left to fade away…

Over time, this core wood is slowly broken down by fungi. In the very oldest trees, the core is lost completely. Perhaps the most famous of these wood-feeding specialists is one you may well have eaten, the Shiitake mushroom. The fungi in turn are eaten by many species, from bacteria to nematodes, insects to mammals, whilst the rotten wood supports many more. Therefore, this soft rotting deadwood actually hosts a complex living food web.

St Andrews Park – The fallen Black Poplar

An oak tree supports over 350 different varieties of insect. But over half of these feed on dead parts of the oak tree.  Bats rely on deadwood cavities to roost, whilst feeding on many species of night-flying beetle that feed solely on deadwood. Redstarts require hidden cavities to nest, whilst searching for bark beetles and moths that grew up in the deadwood. Everything from blue tits to woodpeckers and wood mice to tawny owls rely on deadwood for some part of their existence. By the time an old tree falls completely, upended from its rotting root network, the wood may be dead but the vast diversity of creatures it is feeding are very much alive. 

When we strip out deadwood from a natural environment, often under an aesthetic tidiness premise, we aren’t just taking the wood away. We are slowly eroding the complex living food web that the deadwood feeds. The Bristol Downs has suffered from this for many years. We could have hedgehogs snaffling snails from deadwood retreats and spotted flycatchers nesting amongst the craggy cavities in gnarled out stumps. Animals just need food and shelter to thrive. By removing deadwood, we take away both. There are many ways of leaving deadwood that look aesthetic whilst appreciating the enormous ecosystem service it provides. Good signage can help explain this.

In a time of unprecedented ecological collapse, we must all do what we can to help the natural world. Leaving deadwood in situ is one of the easiest ways to do this. So please, next time you see a fallen tree, don’t look on it as an untidy addition to the landscape, but enjoy it as the next opportunity for nature to reclaim a part in our everyday lives.

@NTGates Feb. 2020

Shocking treatment of Lower Ashley Road trees shows urgent need for Bristol Planning rethink

Bristol has declared a climate emergency. There is an urgent need for all council departments to re-think the way that they work.

At the time of writing, four of the trees in this image have been felled (two Norway Naples and two Indian Bean trees on a different plot).  The value of the five maple trees along Lower Ashley Road was calculated at £200,000 using CAVAT.  Local residents are desperately trying to save the three remaining maples.

This blog discusses six changes that are desperately needed to protect trees on development sites.

  • Planning Decisions regarding important or TPO trees should be considered by committee and not delegated to one officer.
  • It is practically impossible for local residents and other stakeholders to wade through all planning documents online. Planning Officers must highlight important tree issues and have a duty of care to act positively in favour of trees.
  • Bristol should implement policies to retain trees on development sites in the way that has been done in London, Oxford and elsewhere. This includes enforcement and a presumption to retain trees at the edge of development sites.
  • An emergency number to address immediate tree felling issues. 
  • It is a false choice to say that we can either have social housing or trees. With clever designs, we can retain existing trees and have better social housing.
  • Replacing felled trees, even when applying the Bristol Tree Replacement Standard, is second best to retaining existing large urban trees. We get the benefits from existing trees now – we have to wait decades for their replacements to grow.

Over the last six months there have been half a dozen articles in the local press and now one Guardian article about the shocking planning decision to allow removal of five Norway maple trees with Tree Preservation Orders (TPOs) on Lower Ashley Road, one of the most polluted streets in Bristol. There have been two meetings with the mayor who also visited the site and there is now a vigil by protesters on the site: police have been called on several occasions. All this indicates a planning process that has marginalised local residents and failed to take into account the value of the trees.

The Bristol Tree Forum appreciates the efforts by Mayor Marvin Rees to try and resolve the situation after the event. He visited the site and then convened two meetings in City Hall which he chaired. We have been impressed by his serious engagement and the way that he has brought all the interested parties into the room and handled the discussion. But, as we think he would agree, this is the wrong way around. Discussions such as this should happen before the planning decisions are taken so that there is community engagement in the decision making.

Planning Decisions regarding important or TPO trees should be considered by committee and not delegated to one officer

That we have got to this stage shows a serious failure of both Bristol City Council Planning policy and its implementation. The decision to remove the trees was taken in 2015/16 by one planning officer as a reserved decision. It did not go for to the Planning Development committee for a considered decision. Looking over the documents it doesn’t seem that any time or thought was given to the trees. The Arboricultural Report provided by the developer does not even state whether the trees had TPOs, and indeed there is no discussion of the TPOs in any of the documents in that planning application, with the only mention on the “constraints” page. In 2015, The Bristol Tree Forum commented in opposition to the proposal but even the BTF was unaware that the trees had TPOs. Whilst BCC insists that the decision was “valid”, without a mention of the TPOs there was insufficient information to allow intelligent consideration of the proposal, so we question that decision. Sufficient information for intelligent consideration is one of the fundamental principles of a “proper consultation” as decided by Lord Woolf*. The first mention of the TPOs in a document is in the Officer’s Report outlining the delegated decision. 

Unfortunately this is not an isolated failure: trees all over Bristol are being unnecessarily sacrificed as a result of applying ideology from the 1960s. For example a single planning officer gave the green light for the removal of some 25 trees on the Redland Girls School site, in a conservation area, despite the fact that the removal is purely for landscaping.

Redland Green Trees: damage to tree roots caused by driving construction vehicles over them can result in the eventual failure of the trees. In a failure of planning, no root protection zones or Arboricultural Methods Statements were ever established for these trees, despite permission being given for the construction company to store materials on Redland Green.
It is practically impossible for local residents and other stakeholders to wade through all planning documents on line.  Planning Officers must highlight important tree issues and have a duty of care to act positively in favour of trees

Important tree issues need to be highlighted and openly discussed during the planning process. Planning Officers already implement policy regarding flood risk, traffic management and other construction matters. The Bristol Tree Forum is asking that tree protection is included too as is done in other local authorities (Examples are Oxford and Islington, below). In addition, trees on or near active development sites must be properly protected.

We see applications with no information on the Bristol Tree Replacement Standard calculations, or obviously incorrect information being supplied. Documents such as these should be rejected by the planning officer.

Redland Green Trees. Permission was given for this TPO Ash tree on Redland Hill to be removed (in addition to several others on the site) to allow articulated lorries to enter the building site. In the event, the gateposts were never widened, articulated lorries didn’t enter the site as this would have been extremely difficult even with gate widening and the tree was retained until Aug 2019, when it was removed anyway.
The Indian Bean trees growing on the next-door site on Lower Ashley Road before they were felled. Together with the Maples nearby, they formed a welcome green oasis in an otherwise treeless urban setting.
All that remains of the Indian Bean trees which were chainsawed following rejection of an application that was refused because the trees were felt important and merited TPOs.  The trees were removed anyway. We are trying to find out why the trees were not then protected with TPOs.
An emergency 24-hour number to address immediate tree felling issues. 

Bristol is at risk of becoming known as a Mad Max world now that unqualified people are wielding chainsaws from ladders above passing pedestrians with no enforcement consequences, often on public holidays, sometimes in the evenings and even at night. A proper approach for addressing this problem needs to be developed in collaboration with the police. It is unfair to send a single tree officer on their own to deal with issues of public order. Multiple phone calls and sometimes hundreds of emails to numerous council departments very quickly overload already overstretched council officers. It is no good passing the buck to the Health and Safety Executive. Therefore we need one emergency Bristol City Council number.

Lower Ashley Road.  Bristol City Council urgently needs to come up with a procedure to address dangerous activities by unqualified people using chainsaws over pavements and roads.
A Maple with the arrow sign captioned ‘here’ pointing at a partially sawn limb : Following complaints over an entire week, this dangerous almost severed branch was only addressed after an article appeared in the Bristol Post.
Trees growing at Cotham School were removed by Skanska (2008) in the afternoon before Good Friday when no enforcement action could be taken.
Bristol should implement policies to retain trees on development sites

Where possible we should build developments around existing trees. There should be a presumption to build around existing trees and particularly to retain trees at the edge of development sites. 

The developer’s arboricultural report for Lower Ashley Road states that “In order to retain the trees within any new scheme, the front of any new building will need to be sited a minimum of ten metres from the existing site boundary”. We have heard this assertion stated by developer and planner as “the ten metre rule”.

There are many examples where mature trees are retained close to new buildings, in London, Oxford and elsewhere. This must become commonplace in Bristol too.  A Trees and Design Action Group article describes the construction of the Angel Building (Islington, London) around existing mature trees. No cowboy chainsawing there. Instead extreme care was taken in a project that was led by landscape architects. For example:

Deliveries needed to be conducted on a daily basis. To enable this, the Tree Protection Plan (TPP) and Arboricultural Method Statement (AMS), developed by appointed tree specialist JCA, in coordination with the project landscape architect and the council tree officer, proposed the use of a porous load-spreading cellular confinement system (Geoweb) braced with timber frames.

All existing trees were irrigated during the two-year construction period following a sporadic pattern imitating rain. Because irrigation was fed with calcium-rich London tap water, the system was fitted with filters to avoid increasing the soil pH.

The Clifton Suspension Bridge visitor Centre (Alec French Architects) in North Somerset, not Bristol, is within 2 metres of an important tree.  The roof line has been cut away to accommodate a branch.
Aurora Building, Counterslip, Bristol.  Energy efficient, outstanding architecture and built extremely close to an existing plane tree.
It is a false choice to say that we can either have social housing or trees. 

Although the 2015/16 planning approval that is being used to justify removal of the trees was for student accommodation, the current proposal, still under consideration, is for social housing that Bristol desperately needs.  We are surprised that, despite this new undecided application, the developer is still able to undertake work under the old approved application which they no longer intend to pursue.  Shouldn’t the slate be wiped clean so we have a chance to revisit the whole plan with the trees still in place rather than be forced to decide without them?

The developer, planners and others have presented a false choice stating either we retain the trees, keep the site derelict and leave 28 families homeless, or we remove the trees. 

These trees are right on the edge of the development site. With clever designs, led by a landscape architect (not even apparent that one has been engaged for this project), and carefully constructed foundations (e.g. screw piling), the developer could build close to the existing trees. The result? Better social housing which benefits from existing green infrastructure and provides a more pleasant environment with some protection from the noise and pollution of this busy road.


  • Lord Woolf MR in R v North and East Devon Health Authority, ex parte Coughlan [2001] QB 213, [2000] 3 All ER 850, [108] as follows: whether or not consultation is a legal requirement, if it is embarked upon it must be carried out properly; to be proper, consultation must be undertaken at a time when proposals are still at a formative stage; it must include sufficient reasons for particular proposals to allow those consulted to give intelligent consideration and an intelligent response; adequate time must be given for this purpose; and the product of consultation must be conscientiously taken into account when the ultimate decision is taken.

Council no longer manages trees on educational sites – Part I

There are some 166 educational sites and 63 playing fields across the city. Together they cover over 560 hectares and form a significant proportion and an important part of the city’s open, green spaces.

Despite this, Bristol City Council no longer manages trees growing on many of these sites and their related playing fields. We are not certain, but we imagine that this situation has come about as a result of the decline in local authority control over state educational provision with the rise of independent Academies.

We issued a Freedom of Information request (FoI) to try to find out which sites remain under the control of the Council, but our request has been refused on the grounds that answering it would impose a significant burden on the council. Our more generic request at the end has also been refused on the same grounds.

The trees at Stoke Lodge Playing Fields

Recent events at Stoke Lodge and the playing fields there perhaps best illustrate our concerns and the potential threats to the many trees growing on land set aside for educational purposes.

The site was leased for 125 years to Cotham School in August 2011. Interestingly, the Council agreed to retain its responsibility for all the trees growing on the site. It also agreed to indemnify the school for any damage the school might cause to the trees and to insure against this risk.

Stoke Lodge Playing Fields are located to the west of the city in Stoke Bishop ward and cover some 8.7 hectares of open space. Historically they were part of the grade II listed lodge (now an adult learning centre) of the same name which covers about two more hectares and contains an arboretum of important trees (the survivors of a collection that formerly spread right across the historic lodge grounds).

Unlike most of the land around it, this part of Stoke Bishop is not in a Conservation Area. For some 70 years, the whole estate, which until recently had never been seen as a divided space, has been used by the local community and is designated an important open space. Nearly all the trees on the Stoke Lodge estate are subject to Tree Preservation Orders (TPO) which were placed on the trees in early 2012.

The TPO trees and canopies

In the summer of 2018 Cotham School announced that it intended to erect a fence along the boundary of its leased land. They stated that they did not require prior planning permission to do so because they were exercising their statutory Permitted Development rights. After an initial dispute about whether the school could indeed use Permitted Development rights, in January 2019 work began to erect the fence.

It was at this point that the Bristol Tree Forum became involved after it became clear that the proposed route of the fence would pass through the root zones of a large number of important trees, many of which were the subject of a TPO.

The original plan – the fence passing through the root zones of many protected trees.

There then followed a protracted period of back and forth representations while we and the local community fought to get the fence relocated to avoid damaging the trees. This was partly successful. Where it was not, we were able to insist that the methodology for erecting the fence where it still passed through tree roots was modified to minimise damage. Even so, it took the constant vigilance of the local community and BTF representatives to ensure that Cotham School did not ignore the conditions placed upon it.

Setting aside the issue of the siting of the fence, our primary argument has always been that TPO law requires a prior planning application to be made (and approved) before any work is undertaken that could cause damage to TPO trees. Initially, the Council rejected this argument, effectively stating the Permitted Development rights trump primary TPO legislation. It also argued that, anyway, it could not proactively prevent damage to TPO trees, but had to wait until the damage has been done, which is, frankly, absurd. We continued to challenge these interpretations and, eventually, the Council conceded our points, though only after the fencing had been completed.

Things then appeared to return to normal,except that the community was now largely confined the unfenced areas around the boundaries of the site. As a result, the trees around the boundary are being exposed to heavier traffic through their root zones. We are concerned that this may have a long-term, adverse impact on their health.

Then, in August of this year, and without any warning, contractors arrived to lay cable ducting across the site so that video surveillance equipment could be installed. Using a mini digger they immediately set about driving over and cutting through the root zone of a TPO Common Ash growing on the boundary of the site. Other non-TPO trees (some privately owned) were similarly damaged.

Digger in amongst the TPO Ash roots

It soon became clear that the contractors had neither been advised of the TPO status of the tree nor of the proper methods to use when working within tree root zones as set out in BS 5837 (Trees in relation to design, demolition and construction – Recommendations), or in the NJUG Guidelines for the Planning, Installation and Maintenance of Utility Apparatus in Proximity to Trees. This was despite the Council being aware of, and engaged with the school’s plans.

We lodged a complaint with the Council’s Planning department. As a result, enforcement proceedings were commenced and the school, whilst narrowly avoiding prosecution, was obliged to take remedial action to try to mitigate the damage caused to the tree. The council also felt obliged to remind the school of its obligations to TPO trees:

And this is a site where the trees are still under the ‘guardianship’ of the Council! What about those sites where the care is vested with the school?

Our concerns remain for the future health of those trees whose root areas had been invaded by the fence installation. We have also continued to express fears about other continuing threats to the trees arising as a result of other activities on the site. So far, our concerns have been ignored.

For example, continuing root compaction and branch damage is being caused to the Persian walnut growing by the gate close to the rear car park and to the trees growing beside the Parrys Lane entrance. This is the result of grass mowers and other service vehicles using these entrances to gain access to the site. We are told the access point has been moved to the Parrys Lane entrance, though that too involves vehicles passing over tree roots.

Driving over the walnut’s roots on the way to mow the playing fields

Historically, it looks like vehicles accessed the site from behind the Children’s Play Ground on the southwest of the site, so did not need to drive over any tree roots. The presence of the fence and lack of any gate there has now closed off that option.

The school’s contractors also continue to mow within the root zones of the two large Turkey oaks (BCC-77025 on the eastern end & BCC-77059 on the western end) that grow inside the playing fields fence.

The eastern Turkey oak

However, the Council and the school decline to address these issues saying that they have made adequate arrangements to safeguard the trees.

STOP PRESS – 4th January 2020 – since writing this blog, Cotham School has felled a TPO protected Elder (plus five others) on the Eastern side of the playing fields and poisoned it with Glyphosate. We have informed Bristol Council Parks and Planning Departments and asked them to investigate. They advise:

“The felled Elder trees were not included within or protected by the TPO covering the adjacent Sycamore tree.

It is very unlikely that roots from the Elder trees will have grafted with the roots from the Sycamore tree. Also translocation of herbicide between grafted roots is very unlikely.*

We are not aware of any plans to fell the twin stemmed Oak beside the white shed at the eastern end of Stoke Lodge Playing fields.”

But, when we asked Parks if these works were done with their prior knowledge and agreement, or if the department had approved the application of Glyphosate to the tree roots, or if they had seen the School’s Aboricultural Management Scheme, they answered ‘No’.

It seems that the school had complied with their obligation to get consent from the Council, their Landlord, but that the Council’s Education Asset Management team had failed to consult Park’s specialist tree officers about the plans.

More details can be found here.

Before the Elders were felled
The aftermath

Cotham School has issued these FAQs – 33 to 38 in response to this issue.

The fate of other educational sites

In the meantime, we have no idea if or how other schools are managing the trees on their sites, or if the Council is consulted when they do.

Even though, in most cases, educational sites are still on Council-owned land, the Council only needs to be told if the trees have a TPO or are growing in one of the city’s 33 conservation zones (or, we assume, if the Council’s lease with the school keeps the management of the trees in the control of the Council – as was the case at Stoke Lodge).

Given that Bristol City Council does not normally issue TPOs for trees on its own land, arguing that it is a good landlord and will look after important trees appropriately, it is unlikely that trees that have been handed over on other educational sites will have been protected by a TPO. Perhaps the council should now review its policy where it no longer manages trees growing on educational sites in light of this history.

Certainly it seems that new tree planting need no longer involve the Council. For example we recently observed that several newly planted trees at Cotham School’s main site had died. It was only when we noted that the dead trees were missing from the Council’s tree stock data for the school that we learned that they were no longer responsible for the trees on the site. We have now been told by the school that the trees were planted as part of a recent development and that the failure of these dead trees will be ‘rectified’ soon. Meanwhile, it seems that these new trees are no longer selected, managed or mapped as part of the Council’s wider tree stock strategies and that the existing trees on the site are no longer the Council’s concern.

Presumably, similar arrangements are happening across the city with other educational sites being left to make their own, ad hoc arrangements to plant trees or not. Given that the One City Plan aims to double tree canopy cover over the next 25 years, it seems a great shame that this important land bank of possible new planting sites might have been excluded from helping to achieve Bristol’s plans.

We are also concerned that school governors (quite apart from lacking the necessary skills to manage the trees growing on their sites) may not yet have realised the full implications of the practical and strategic obligations that taking on such an important part of Bristol’s tree stock places upon them. As a result, they are likely to have to buy in (at our expense) ad hoc expertise, thereby possibly overlooking the wider strategic considerations that are needed when it comes to managing trees across the city.

This, coupled with the distinct possibility that well-meaning but unqualified Council officers may be making critical decisions about the welfare of trees on educational sites, makes for a very worrying situation.

*Here is a contrary view about using Glyphosate around and on trees – Tree pits: plants vs glyphosate

Ancient and Veteran Trees explained

These two terms are in common use, but they have specific meanings when it comes to their conservation. All ancient trees are veterans, but a tree may qualify as a veteran without being ancient.  Most British trees increase in girth over their lifetimes by 2.5 cm a year. They grow faster when young, when in the open as opposed to woodland, and when in good soil rather than bad. They grow slower as they get older. Some species grow faster than average, such as Black Poplar, Plane, and Wellingtonia, and some more slowly, especially Limes and Hawthorns.

Trees are very good at vegetative reproduction, so that they are effectively eternal. Some create their own clumps, each tree being a clone. They do this by branches that arch down to the ground, root, and send up new vertical trees. The Tortworth Chestnut, which was regarded as ancient in King Johns reign, is a good example, but some of the limes on the Downs are doing this. Some trees send up new shoots from the base of the trunk which eventually replace the original tree. Many trees if cut to the ground, by storm or men, will promptly create new shoots, and this is the basis of coppicing which was a standard woodland management tool from at least Roman times. There is a Small-leaved Lime at Westonbirt Arboretum that now consists of a ring of clones about forty metres in diameter.

Ancient trees should be at least two hundred years old, and hence have a girth of more than five metres. I have measured 120 trees in Bristol with this girth, and there are many more in Ashton Court that I have not checked.   They matter because they provide a range of habitats to a range of species. They are always hollow, often squat,  having long since lost their upper branches, their hearts eaten out by fungi and beetles, full of nooks and crannies, and often clothed in lichens and ferns. They are most frequently Oaks, Sweet Chestnuts, Planes and Cedars.

Veteran trees are defined by their individuality. They will be mature, around 140/150 years old, about three metres in girth, mostly still standing tall. Fine, significant specimens of their species both in form and biodiversity. They are candidates to become Ancient, they may be starting to go hollow, and hence be of concern. They may need management to avoid their becoming top heavy, or developing a dangerous lean. They will stand out from other trees in their particular locality and may have planning protection as a consequence. They may also have special features of note, such as being multi-trunked.

Trees and Planning

The National Policy Planning Framework document (issued in July 2018) has the following definitions at Appendix 2: Glossary.

Ancient or veteran tree: A tree which, because of its age, size and condition, is of exceptional biodiversity, cultural or heritage value. All ancient trees are veteran trees. Not all veteran trees are old enough to be ancient, but are old relative to other trees of the same species. Very few trees of any species reach the ancient life-stage.

Ancient Woodland. An area of woodland that has been wooded continuously since at least 1600 AD. It includes ancient semi-natural woodland and plantations on ancient woodland sites.

Irreplaceable habitat: Habitats which would be technically very difficult (or take a very significant time) to restore, recreate or replace once destroyed, taking into account their
age, uniqueness, species diversity or rarity. They include…ancient woodland and ancient and veteran trees….

Paragraph 175 (at page 51) of the framework states:

When determining planning applications, local planning authorities should apply the following principles:

c) development resulting in the loss or deterioration of irreplaceable habitats (such as ancient woodland and ancient or veteran trees) should be refused, unless there are wholly exceptional reasons and a suitable compensation strategy exists;

Paragraph 2.17.6 of DM17: Development Involving Existing Green Infrastructure – part of the Bristol Local Plan echoes this:

Due to their characteristics and value, Aged and Veteran trees are considered to be of relatively greater importance than other trees and even trees of a similar species. Aged trees, by definition, have developed characteristics associated with great age and often have particular landscape and townscape value. Veteran trees are considered to have particularly important nature conservation value. Both will often have significant visual amenity, and potentially historic and cultural importance. As such their loss or harm will not be permitted, and the design and layout of development will be expected to integrate them into development.

These guidelines apply whether the tree or woodland grows in a public or a private place.

R L Bland

About Richard

Veteran pine threatened with destruction

There is a Black Pine (a Pinus nigra) in the back garden of 32 St John’s Road, Clifton, BS8 that its current owner wants removed. Its size suggests that it is probably at least 100 years old. If anything, and given the amount of management it has survived, it is more likely to be about 140 years old as it is very similar to the Black Pines on the Downs which were mostly planted around 1880. It has been protected by a Tree Preservation Order since 2005.

The tree is not easily seen from St John’s Road, but if you go round the corner to Chantry Rd and look north between the back gardens you cannot miss it. It is magnificent! 20 metres tall, with a stately crown around seven metres wide and a stem diameter of 85 cm.

St John's Rd Pinus nigra

The applicant no longer wants us to see the arboricultural report, based on an inspection of the tree in January 2017 (submitted with a recent application, but now withdrawn) which does not agree that the tree needs to go. Even though its previous management has been less than ideal with some resulting damage and there are the usual signs of ‘decay’ associated with the tree’s age, the tree is in ‘fair condition with no risk of imminent decline‘.

The surveyor goes on to observe that ‘The tree is a prominent specimen within the local landscape with high visual amenity. Being evergreen its prominence increases during the winter months, when the surrounding deciduous trees have lost their leaves.

He concludes ‘In my opinion the tree may be retained in the short to medium term…I recommend that it is inspected annually and after periods of extreme weather’.

Despite this, the owner wants it gone and has even persuaded some of their neighbours to support the application, with complaints of the fear of it coming down or losing its branches, and the inconvenience of fallen pine needles and possible blocked gutters.

The new National Policy Planning Framework document (July 2018) has the following definitions at Appendix 2: Glossary.

Ancient or veteran tree: A tree which, because of its age, size and condition, is of exceptional biodiversity, cultural or heritage value. All ancient trees are veteran trees. Not all veteran trees are old enough to be ancient, but are old relative to other trees of the same species. Very few trees of any species reach the ancient life-stage.

Irreplaceable habitat: Habitats which would be technically very difficult (or take a very significant time) to restore, recreate or replace once destroyed, taking into account their
age, uniqueness, species diversity or rarity. They include…ancient and veteran trees….

Paragraph 175 (at page 51) of the framework states:

When determining planning applications, local planning authorities should apply the following principles:

c) development resulting in the loss or deterioration of irreplaceable habitats (such as ancient woodland and ancient or veteran trees) should be refused, unless there are wholly exceptional reasons and a suitable compensation strategy exists;

Paragraph 2.17.6 of DM17: Development Involving Existing Green Infrastructure – part of the Bristol Local Plan echoes this:

Due to their characteristics and value, Aged and Veteran trees are considered to be of relatively greater importance than other trees and even trees of a similar species. Aged trees, by definition, have developed characteristics associated with great age and often have particular landscape and townscape value. Veteran trees are considered to have particularly important nature conservation value. Both will often have significant visual amenity, and potentially historic and cultural importance. As such their loss or harm will not be permitted, and the design and layout of development will be expected to integrate them into development.

Whilst this application to fell the St John’s Road pine is not, perhaps, strictly ‘development’ in the way that these policies intend, the principles they adopt must surely still apply.

A tree in a private space is not the exclusive preserve of those who happen to own it at any given moment, to stand or fall as whim dictates. We all benefit from trees, whether publicly or privately owned, and our planning law recognises that.

The St John’s Road pine probably has a CAVAT value of around £96,500, but this hardly begins to describe its true value to us – the delight it gives when first seen, the web of life it sustains in its branches, trunk and roots – never mind the carbon it has sequestered or the pollution we have dumped it has absorbed or the oxygen it has generated!

The pine may not be an ancient tree, but it is certainly a veteran tree, with all the characteristics that our national and local planning policies describe. Its value to the wider Bristol community has already been acknowledged by making it the subject of a Tree Preservation Order and requiring permission to be granted before anything can be done to it.

Bristol’s Mayor, Marvin Rees has challenged us to double tree canopy cover from around 15% to 30% by 2050. If we are serious about achieving this, then we must also resist these ad hoc attempts to remove trees like the St John’s Road pine.

The current planning application may be found by going to Welcome to Planning Online page, selecting Planning – Simple Search option at the bottom and entering 18/04039/VP in the last field at the bottom of the page. Press Search and , after a few moments, you will be taken to the Planning- Application Summary page headed ‘18/04039/VP | Austrian Pine (T1) per TPO No 940 – fell. | 32 St Johns Road Clifton Bristol BS8 2HG’.  The documents, including various comments made to date, can be found under the Documents tab.

If you agree with us, and object to this magnificent pine being destroyed, please lodge your comments saying so on the planning website using Comments tab in the link above asap. We offer help navigating the Planning pages and with filling in your comments here.

 

 

Planting and replacing Bristol’s street trees with Section 106 money

There are some 38 s.106 agreements worth more than £400,000 available just for planting trees in Bristol.

BCC Area 01

Section 106 (of the Town & Country Planning Act 1990) agreements are private agreements made between local authorities and developers. Some Section 106 agreements are specifically made to replace trees lost because of development. In Bristol, these agreements are made under the Bristol Tree Replacement Standard (see pages 20 & 21). They often also require that trees be planted within a one-mile radius of a development site. The current total value of these funds is more than £400,000.

There are also another 27 agreements that relate to ‘Parks & Open Spaces’ valued at more than £450,000, some of which might also be used to plant trees, but subject always to agreement with Bristol Parks Forum and other local ‘green space’ community groups.

Here is a summary of the current tree-specific agreements grouped by Ward and the new BCC Administration Areas:Ward S106 fundsBackground Notes

Of the 52,017public trees and tree sites managed by the council, a third are street trees. Across the city there are 944 vacant tree sites, 542 of which are places where street trees once grew. Bristol Tree Forum is negotiating to have these sites made available for sponsorship. The remainder of these tree sites are in housing estates, parks, cemeteries, amenity areas and many other green spaces.

None of these sites is available to sponsor but there are currently another 707 sponsorship sites, of which 246 are in streets. These figures constantly change as trees felled are added and sites sponsored are removed. Figures for sponsorship sites where a sponsor has come forward, but the tree has not yet been planted are not published.

These sites could also be funded by Section 106 money. This makes 1,651 sites across the city where trees could, potentially, be replanted. Of these some 1,198 lie within one or more of the areas specified by these Section 106 agreements and 417 of them are on streets.

Replacing all Bristol’s lost trees using only Section 106 agreement monies would cost £765.21 per tree. Planting trees in new sites (sites where there was never any tree) may be more expensive: £3,318.88 per site if the pavement must be lifted, services are disturbed, and a specially designed tree pit installed. If all Section 106 agreement funds were used to replace just lost trees, then some 540 trees could be replaced – 45 per cent of the total number of sites available.

Figures available for tree planting on streets show that 608 street trees were planted between 2013 and 2018, an average of 122 per annum (We are happy to provide the reports and data upon which this table is based on request).Trees Planted tableWe have now been able to establish that the Council felled 1,304 trees over the last three years. We have not yet been able to find what sort of trees they were or where they we located, but it is likely that most were located on streets. 363 street trees were planted over the same period.

* This figure constantly changes. As trees are felled, they are removed from the main BCC asset register. The site disappears until a new tree replaces (if it ever does) the one lost. Trees are usually planted during the winter months when most trees are dormant.

Here is a pdf of this blog.