George Monbiot on Street Trees

George Monbiot has been writing about street trees.  Whilst I am glad he is raising the profile of the subject, I am struck that he seems to ignore some issues that many local authorities regard as central.

Chief among them is insurance.  For Councils like Brent this is one of the major factors in street tree management.  Species like London Plane can grow to a huge size, and their roots start to undermine people's houses.  Insurance companies then have a valid claim against the tree owner, the Council in the case of a street tree.  Once a successful claim is made for one tree in a street, it is frequently followed by a cluster of similar claims in the same area.  Avoiding the expense of such claims is a major factor for Councils.

A second issue he seems to underestimate is the difficulty of planting trees sustainably.  Urban environments are distinctly unfriendly to trees with paved areas depriving them of water, pollution especially from traffic, high temperatures in Summer and so on.  Finding tree species robust enough to cope needs specialist knowledge.  I don't know whether the species list used by our own contractor Gristwood and Toms is the best one, but the point is that you need an arboriculturalist to make a judgement.

The third issue that occurs to me is the practical one of uniformity.  As well as encouraging biodiversity, a variety of different species should make the tree stock less vulnerable to particular diseases such as ash tree dieback.  Those are obviously important advantages. However, Councils also have to look after very large numbers of trees.  In Brent's case we have about 27,000 street trees spread over about 480km of streets.  Treating each tree as an individual sounds lovely but entails great expense.  For such a large number of trees, you realistically need a more standardised approach for cost reasons.

The Guardian version of his article also carries a lot of comments lamenting the supposed negative effects of budget reductions on biodiversity.  I actually think the opposite is true.  Brent has systematically changed its planting regime in parks in the past three years.  I have been advised that this is better for biodiversity overall.  I must admit that aesthetically I preferred the kind of flowerbeds you used to have at the entrance to Roundwood Park, but in terms of biodiversity those flowerbeds were not especially rich.  They were also expensive to plant and maintain, and very water thirsty.