The urban forest of Merchiston and Greenhill
How to ensure good outcomes and a system fit for purpose?

A blog by Will Ellis

Our first blog post described the way trees are regulated in conservation areas like the Merchiston and Greenhill Conservation Area (MGCA). Our second blog analysed the data collected in a recent study of several years’ worth of notifications by residents wanting to carry out tree work in their gardens. In this blog we look at the goals of the regulatory system; at the outcomes that are sought by those subject to regulation and those in charge of regulation; and at questions about the fitness for purpose of the current system.

A reminder about the law

In the Town and Country Planning (Scotland) Act 1997 (as amended), privately owned trees can be protected through a “Tree Preservation Order” (TPO) if the local authority deems it ‘expedient in the interests of amenity’ or if the trees are of ‘cultural or historical significance’. A TPO can be applied to any tree or group of trees, whether inside or outside a conservation area, so long as the amenity and expediency criteria are met. Within conservation areas, residents are required to notify the planning authority of their intended tree works, giving the authority a chance to assess whether a TPO should be applied. This reflects the particular contribution that trees make to the urban landscape in areas of valued architectural character and streetscape.

And a bit of history

Accompanying the post-WW2 rebuild across Britain, the focus of the TCPA was on conserving and maximising the amenity of the built environment. This undoubtedly reflected the needs of a population that had experienced the devastation of war.

Howard’s Garden City movement had entered the cultural imagination – stressing the importance of greenery and open space in urban planning. Even if trees were at the periphery of policy considerations (public health, the revival of industry and rebuilding of infrastructure being the dominant concerns), the post-war legislation reflects an awareness of green spaces and the public benefit they offer.

Although the system for regulating tree work has undergone some adjustments since post-war Britain, it remains in outline the system that was designed then. But our contemporary world faces even larger and more pressing challenges. Faced with two generation-defining problems – the crisis in biodiversity and the climate crisis – it’s appropriate that we re-examine our goals for the urban forest, the outcomes we want regulation to support, and the fitness for purpose of the current system.

A new appreciation of the urban forest

Our understanding of urban trees and their benefits has greatly expanded in the decades since the postwar period. We now know that urban trees can help alleviate the environmental challenges of urban living such as elevated temperatures, air pollution, flooding, and biodiversity loss. This link explains the beneficial role that trees play – https://www.forestresearch.gov.uk/climate-change/advice/urban-forests/

Nature now has a firm place in the planning system. The National Planning Framework 4 (NPF4) makes explicit the importance of biodiversity and provisions for nature in urban planning and commercial development. The City of Edinburgh Council (CEC) has itself declared a climate and nature crisis in the city, mobilising its own central nature team, and dedicating resources to publicly-owned trees.

However, the management and governance of private (garden) trees have not yet been modernised in the same way. My interviews with planners, residents, councillors, arborists, and academics – most of whom reside or work within Merchiston & Greenhill – suggest that fresh thinking is needed about the purpose and practicalities of regulation; and that local communities can offer hugely useful and subtle insights into these complex issues.

Valuing Merchiston’s trees

Our trees are well loved. Participants overwhelmingly recognised the multiplicity of ways that Merchiston’s urban forest benefitted residents – not just locally, but throughout Edinburgh as a whole.

“Particularly in areas like Merchiston and Greenhill, it’s very much part of the attraction of the neighbourhood to have so much greenery… yeah, the more trees the better.” Merchiston Resident

Most of the people I interviewed thought that canopy cover – often used interchangeably with “greenery” or “green area” – should be conserved to the greatest extent possible.

“The protection of the green bits – particularly in cities -is really important.” Local Arborist

Unsurprisingly for a densely-populated area rich with mature and historical trees, the assertion that preservation was more immediately important than planting was popular amongst residents, particularly those who had trees.

“Normally it’s better to keep the trees that we have rather than plant new ones and that should be the priority” Local Resident

Consequently, it was emphasised that the goal of tree governance should be to prioritise these positive outcomes:

“If this conservation area here wasn’t here, then controlling what was happening within the area; you could have all kinds of things being cut down just to build a little hut or something” Local Arborist

“If councils are thinking about tree equity and they’re thinking about approaches to ensuring good levels of tree cover or tree access, thinking a lot about [the notification system], or about what happens on private land is probably quite important.” Merchiston Resident & Academic

‘Amenity’ – a core issue

In our current system, trees may be protected from felling or other work if a local authority judges it in the interests of ‘amenity’ to do so. ‘Amenity’ is not defined in law so local authorities have to make sure their judgements are fair, consistent and reasonable; and that, in any given case, protection by way of a TPO brings a degree of public benefit, now or in the future. (The second criterion relating to historical or cultural significance is important but not, we understand, frequently used by local authorities in determining whether a TPO should be applied.)

Typically, local authorities in Scotland consider various factors in deciding whether ‘amenity’ has been established: the visibility of the tree to members of the public, the size and form of the tree, its rarity, its contribution to and relationship with the landscape; and (if a tree is in a conservation area) the contribution of the tree to the character and appearance of the area. It is an elastic term, as noted by one tree specialist –

“Amenity… what does that mean?… it’s a very broad term. It’s not defined in the legislation and it’s kind of good that it’s broad because every tree has amenity. So, you can make a case for [protecting] a tree as long as it’s visible to somebody other than its owner.” CEC Arboriculture Officer

But the term, in inviting consideration of mainly visual properties, has its limitations. No doubt the factors above are all relevant and necessary; but are they sufficient? Does a tree not have value even if it is not observed by the public? What about scientific value, contribution to biodiversity or recreation, venerability (particularly ancient specimens) or climate change mitigation? Should it be possible to make a TPO on any of these grounds, or only and primarily on visual appearance?

In our view, the core criterion of ‘amenity’ needs to be elaborated in order to capture the range of strong contributions that trees can make to the environment as well as to the urban landscape. In my interviews, some felt that amenity was an appropriate tool for judging whether or not to protect a tree. But many argued that this criterion is incomplete; and that there are many other reasonable justifications – like biodiversity support or urban cooling – that could be advanced for protecting trees.

Regulation & the power balance

The underpinning legislation, as it applies to conservation areas, upholds the property rights of residents. They do not seek ‘permission’ from their local authority when planning tree work or tree felling: they ‘notify’ their authority, which then has 6 weeks in which to decide whether to intervene by way of a TPO.

Residents articulate their private interests through their notifications: the local authority has to determine where the public interest lies. The current system does not require residents in conservation areas to offer any justification for their intended tree work/ tree felling; and local authorities have no explicit power to discuss options to felling with residents.

In my interviews, some local residents emphasised the importance their property ownership rights. Regardless of the value they placed on local trees and their benefits, they asserted that it was important that their decisions about their gardens should be unfettered.

Given the serious value of trees to the quality of urban life and given the scale of the environmental and climate challenges that we face as a society, perhaps there needs to be a new debate about the right balance between private rights and public interest. This seems especially salient in relation to tree felling (see below).

A system fit for purpose?

Any system of regulation must meet certain characteristics. It must be only as onerous as is required to deliver the policy purpose; it must command the assent of those regulated as well as the regulators; it must be fair, transparent & consistent; and it must be operationally feasible and reasonable.

The sense of a weak system of governance was pervasive throughout my interviews, and, unanimously, people wanted to see it become stronger. At the extreme, it could be argued that we need to turn the system on its head – by establishing a default position that felling in conservation areas is prohibited unless certain conditions are met. While that would counteract some of the weaknesses in the current system, its practical implications would need to be considered carefully. The fettering of proprietors’ liberty over their possessions would no doubt be contested. The burden of such a move on the regulator would also need assessed. As one interviewee said

“The risk of expanding tree protection, of course, is that everyone just starts ignoring it. And then if you’re not enforcing it, then effectively, there’s no tree protection at all at that point. So, if you expand it too much, you’d undermine the system.” CEC Arboricultural Officer

Participants in my study often posited that changes to the powers of local authorities might provide the local authorities with better tools to create better management and governance outcomes for Merchiston’s urban forest. But the resource constraints on the City Council’s tree specialists are severe and the imposition of new duties, unless accompanied by substantial new resources, would only create a dysfunctional system. As was shown in Blog 2, the local authority makes very, very few TPOs: this cannot simply be a regulatory restriction. The extent to which local authorities are stretched when it comes to garden tree protection cannot be overstated. An arboricultural officer consulted in our project reminded us:

“We receive between 800 and 900 applications relating to trees a year, and they’re being handled by three people.” CEC Arboricultural Officer

Yet even quite modest changes to the law might help to improve outcomes and to strike a better balance between private and public interests in relation to trees. For example, requiring residents to offer reasons to justify any proposal to fell a tree in a conservation area might help to underline the ‘last resort’ nature of such work and to reinforce the point that healthy and mature trees should not be lost lightly.

Many tree owners and tree surgeons also struggled with so-called “black-and-whiteness” in the current regulatory system. Many thought that there was room for the system to be more detailed, nuanced, or consultative:

“I think maybe there’s space to think more creatively about the way that those orders work. So rather than just protection, thinking a little bit more about what would the levels of protection look like.” Merchiston Resident & MDCC Member

“I think the system should be more consultative… I would like it to be a communal agreement, consensus. But the current system doesn’t allow that.” Merchiston Resident

If local authorities were explicitly empowered to engage in a discussion with residents about their intentions, that too could open up an avenue for creative, collaborative solutions. Those might include adaptive stone masonry where damage to walls is a concern; or proposals for pruning rather than felling; or new planting to offset the loss of biodiversity and carbon capture entailed in felling. Given our estimate of tree loss in the conservation area over the past decade (see blog 2), it seems to us appropriate to consider measures to ensure that felling is only undertaken when all other options have been exhausted.

Any of the adjustments suggested above would require reform of the base legislation – a matter for the Scottish Parliament. While the City Council cannot deliver such changes, it can campaign powerfully for them, if it were inclined to do so. We hope it will.

To me, this all points in the direction of using community-driven efforts to complement the statutory approach to tree regulation so that the specific needs of an area are taken into account.

Conclusion

This all paints quite a clear picture of where there tends to be common ground in terms of the garden trees in Merchiston and Greenhill and, by extension, its urban forest.

Whilst some were satisfied with the status quo, nobody seemed to take for granted the rich and numerous benefits that at least some level of tree protection afforded the local area. Most supported the idea that local authorities should aim to protect urban tree canopy, and that there should be regulatory change to better ensure better outcomes in this regard.

Legislation aside, there are some options and initiatives beyond local authorities that can help us achieve better outcomes locally. For example, some communities have set up ‘Tree Warden’ schemes to exercise voluntary stewardship over local trees, supporting the role of local authorities and encouraging best practice by residents.

Most importantly, the most direct site for change is in our own gardens. In our final article, we provide a set of best practice guidelines for tree owners. It will outline how to easily stay in line with your regulatory obligations, ways to make the regulatory process easier on yourself and others, and some recommendations for how to approach tree work that may impact your local neighbours.