The value of trees

Wheelie bins more risky than trees

What seems to be at the back of the Council's mind is that they would be liable for a tree-related insurance claim if they refused the felling application. Currently all liability is with the airport - as owners of Marlhill Copse. The tree's health and utility are secondary in this analysis. However........The National Tree Safety Survey makes interesting reading:

"So far as non-fatal injuries in the uk are concerned, the number of accident and emergency cases (a&e) attributable to being struck by trees (about 55 a year) is exceedingly small compared with the roughly 2.9 million leisure-related a&e cases per year. footballs (262,000), children’s swings (10,900) and even wheelie bins (2,200) are involved in many more incidents." [National Tree Safety Survey - page 22]

"Public safety is not the only concern when deciding how to manage trees. other broader concerns, such as ecological, landscape and aesthetic value, should also be taken into account." [page 27]

"A warning notice that warns of a specific danger posed by a tree (or trees) may be sufficient to absolve an occupier from liability in that they may, by such notice, have taken all reasonable care for the visitor’s safety in the circumstances". [page 35]

Given that no tree is absolutely safe, the Council needs to accept liability for community assets. A tree is an asset to the community even if it not owned by the Council.

This University of Southampton study shows that the 3 Montereys that the airport wants to fell in 2020 are of the size (diameter greater than 60 cm) and age that Southampton needs more of in order to combat climate change:

The University study uses an analysis tool called CAVAT (Capital Asset Value for Amenity Trees). In addition to this, the value of urban trees through carbon sequestration and avoidance of water run-off is calculated.

This system is described by one of the Southampton Tree Officers as: "CAVAT has been designed for use by local authorities and provides a basis for managing trees as public assets rather than liabilities. CAVAT allows for the contribution of factors of location, relative contribution to amenity social value and appropriateness, and an assessment of functionality and life expectancy. CAVAT aims to calculate a value for a tree that realistically reflects the contribution of the tree to public welfare through tangible and intangible benefits."

Very odd indeed that this system was not used to calculate the initial value of the 3 Montereys in the decision to fell them.

Perhaps because the value of these three trees could be in excess of what the airport paid for the Copse (£260.000)? In fact (dependent on the way the crown size and structure is assessed) the value of T119 alone could surpass this figure. This is before climate change (there is only a passing mention in the material below) and drainage benefits are factored in or adjusted.

The London Tree Officer's Association has details including a quick method calculation spreadsheet:

• https://www.ltoa.org.uk/documents-1/capital-asset-value-for-amenity-trees-cavat

The full academic article is at: https://www.tandfonline.com/doi/full/10.1080/03071375.2018.1454077