In defence of Bristol’s trees

Why are we felling so many trees in Bristol when the city’s stated aim is to double tree canopy cover by 2046? To achieve this aim, we will need to stop felling existing trees, failing to replace those that have to be felled trees AND see at least a five-fold increase in our current tree-planting rate!

It’s been estimated that there are about 600,000 trees growing in Bristol. They cover about 1,300 hectares, an average of 22 square metres for each tree. Together these trees bring us shelter and delight – not to mention all the other Common Goods they offer us. They are a crucial part of our city’s urban space.

The city’s plan to double tree canopy cover over the next 25 years means planting some 25,000 trees (55 hectares) every year over the next quarter century. Over the last ten years we’ve managed to plant just over 7,500 trees annually (mostly thanks to the One Tree Per Child (OTPC) initiative, and thanks almost entirely to private funding).

Most of the OTPC trees are small whips planted in woodland settings, with the larger Standards often being planted to replace trees that have already been felled. However, even if all the 600,000 new trees needed were to be planted today (and even if they all survived), it would still take at least 30 years for each tree to reach its full canopy potential.

Over the last six years (we don’t have the earlier records) the Council has felled over 2,300 of its trees and replaced them with just 1,200 Standards (all with private funding), a net loss of over 1,000 trees (about 180 per annum). This is just a fraction of the trees we have lost. because it covers only Council-owned trees.

BCC trees felled and trees replaced since 2014

We don’t know exactly how many other trees have been felled and not replaced – to planned development or at the whim of their owners – but looking at a sample of nine weekly planning application lists, an average of 15 applications a week are for trees to be felled. In our experience, we know that nearly all these applications will be granted, so that’s another 780 trees lost over any one year. Applications are only required for TPO trees and trees in conservation areas. Bristol’s 33 conservation areas cover about 25% of the city, so this suggests that we probably lose at least another 2,000 trees from non-conservation areas every year. Whether these are replaced or not, we do not know.

The number of trees lost to development is much harder to estimate. Unless the Bristol Tree Replacement Standard has been applied, the developer does not need to replace any felled trees.

Taking all these losses together, we estimate that around 4,000 of Bristol’s trees are felled every year. Whilst some of these may eventually be replaced, this represents an annual loss of about 9 hectares of tree canopy cover – remember that trees with an average canopy of 22 square metres are being replaced with small trees with a fraction of the canopy lost which will take decades to regenerate. This represents 16% of the 55 hectares of annual new canopy we need to create and about 53% of our current annual tree planting output – and we have not even started to plan for the impact on canopy cover as a result of threatened tree losses caused by Ash Dieback and other pathogens.

If we fail to protect the trees we have, then we will never achieve our ambition to double tree canopy cover by 2046. It is for this reason that we have published our manifesto for protecting Bristol’s existing urban forest and invited all Mayoral and Council Candidates to adopt it as part of next year’s planned elections.

Mark Ashdown, Chair of Bristol Tree Forum.

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