Trees and the Climate Emergency

John Parker, CEO of the Arboricultural Association, gave an insightful talk on 25th February hosted by NailsworthCAN at the Arkell Centre. The talk focused on urban trees and their importance socially and in relation to climate change. It was very well received by a well attended audience.

John was a leading light in the creation of the Stonehouse Community Arboretum, and a Management Plan to go with it, that is supported by the local council and community at large. It is something that those who attended the talk were enthused by, and could be a template for a Nailsworth Community Arboretum.

The benefits of trees to society are almost too numerous to list: shade providing cool spaces during heatwaves; water retention assisting in flood management; amenity value for communities; helping in reducing impact of pollution; providing habitat to support biodiversity; support for mental health and social prescribing; enhancing property values. 

Access to trees or ‘Green Equity is a key issue close to John’s heart (and he is hosting a symposium in this in April), because not all communities have easy access to trees. The UK tree equity website provides a scoring system to enable communities to assess their current level of access https://uk.treeequityscore.org/ - In the Stroud District whilst Horsley scores well as No 1, Forest Green is much lower at No 20.

While biodiversity loss in the UK is a significant concern, the UK can at least celebrate having more ancient trees than the rest of Europe put together (ancient meaning older than you’d expect for a given species).

With climate change, things have been changing. The number of oak trees dying when they reach about 700 years old is worrying - they’d be expected to live for at least another 300 years. Lack of water is a major cause, brought on by drought conditions. False autumns are now becoming more frequent when trees are stressed during droughts. This has implications for the planting of new trees because instead of watering them for a few years to let them establish themselves, it is more likely they’ll need decades not years.

Pest and diseases are also taking their toll. John discussed Dutch Elm Disease and Ash Dieback, which most of us have heard of, and others that may be less well known but need to be kept out of the country such as Xylella (deadly olive tree disease). 

Plane trees across Europe are being devastated by a fungal disease, which would bring terrible consequences to London if it came to the UK, given the crucial and ubiquitous role of the London Plane to the city’s parks and tree lined streets.

Yet, biosecurity policies and regulations are too weak. You can import an olive tree from Europe and get it delivered to your home with no checks, despite the risks. As with any disease or pest, once it has reached our shores, it will spread. Any attempts to control it will have limited success, such as with the Oak Processionary Moth which arrived in 2006 and is now endemic in London; it is only a matter of time before it reaches Gloucestershire. 

The survival of the Brighton Elms occurred only because of radical use of a ‘firebreak’ (cutting down of swathes of Elms north of Brighton to protect the remaining population). Without its protective flanks of sea and the downs, most towns could not execute such a strategy effectively.

Political parties and councils are trying to out bid each other with promises of the numbers of trees they will plant. John provided a reality check on these promises. Planting millions of trees will not solve the climate crisis because most of them won’t survive (and in any case, the time taken for them to absorb enough carbon will make it too late to avoid dangerous climate change - we have to do the other things that reduce our emissions in the first place). They won’t survive for two main reasons. Firstly, they won’t receive the care they need to keep them alive, especially during the heatwaves that will become more frequent, and secondly, because we’ll be planting many of the wrong species, because of the mantra ‘native trees’.

Of the 35 trees native to the UK, half of them have good canopies, and many of these will have issues because of emerging diseases and pests. So we must diversify. A recent study ‘Future Climate Suitability of London’s Public Realm Trees’ found that only 0.38% of current trees could be classified as “highly suitable for future climate conditions”. 

We have to get away from the mantra of ‘native species’ and accept the reality of the locked-in changes to the climate (even while endeavouring to mitigate things to avoid it getting any worse, by reducing our emissions). Species such as Tulip, Cork Oak, Magnolia Grandiflora, Olive, and many more, can help us diversify our urban and wider landscape.

Instead of targets to plant trees, we need targets on how many newly planted trees we keep alive, and thrive. That was one of the things John did when he founded The Stonehouse Community Arboretum, with a goal of 95% survival after 3 years. It’s about quality rather than quantity. Labels are produced for trees asking people to water them. The idea has been taken up internationally.

Public services have become so hollowed out that there is simply too little capacity amongst planning officers to enforce standards. Developers will plant some trees to tick boxes but then they die due to lack of care (and it can be cheaper to replant than to water and care for saplings).

That is why a community led approach offers so much, because it is the community that feels the benefits of urban trees, and also feels the pain and loss when they are gone whether as social amenities or as cultural icons.

John’s talk may have been a bit of a wake up call for many who like to think of the subject of trees as warm and cosy, with easy solutions (just plant millions of trees and everything will be ok, we are told). There was nevertheless hope in the talk, but a hope built on action, not wishful thinking.  The harsh realities John laid out are not a reason for despair, if we are prepared to take informed actions, based on the arboreal knowledge that he espoused so  well in his talk.

Rather than the simple, quick fix prescriptions we so often hear about, what if every town in the UK followed Stonehouse’s lead and formed a Community Arboretum? How about Nailsworth? Would you be interested in helping make this happen?

We could then take the time to create a truly ground up community led approach, sustainable over generations.