New research carried out by the London Tree Officers Association (LTOA) using specialist forestry software has revealed that London's tree cover is 21.87 per cent, a figure that will enable the accurate measurement of progress towards the Mayor of London's targets for increasing the city's tree canopy.
The LTOA, which used i-Tree Canopy software to calculate the cover, said the new data is more accurate than previous estimates, including that provided by the mayor, which had generally put the figure for tree cover in London at 20 per cent.
The figure produced by the LTOA for tree cover in the Greater London Authority area includes woodland cover of 7.37 per cent and isolated tree cover - consisting of trees in small groups that do not qualify as woodlands - of 14.5 per cent.
The LTOA has highlighted that the mayor and the London Plan propose targets for increasing the capital's tree canopy by five per cent before 2025 and a further five per cent by 2050. It said progress towards those targets can now be measured more accurately because its survey has a standard error of plus or minus 0.56 per cent.
LTOA chair Dave Lofthouse, who would like to see the mayor's targets increased, said: "For years people have talked about tree numbers, how many trees have been planted and felled, but it should be about volume of canopy and how much oxygen is pumped out and how much carbon is sequestered. If we want to improve the quality of life in cities, we need a bigger urban forest."
He hoped the survey would prompt investment in i-Tree tools, which can calculate the value of urban forest.
An i-Tree Eco survey, developed by the US Forest Service to assess the structural value and environmental benefits of urban trees, was carried out in Torbay last summer. It showed the tree population has a structural value of £280m and an annual carbon storage value of £1.4m. Carbon sequestration and pollution removal are valued at £172,000 and £1.3m respectively.
Planting pledge - Mayor plants 10,000th London street tree
London Mayor Boris Johnson helped plant the 10,000th street tree in London last week to fulfil his election pledge to green up the capital's roads.
He also called for more people to enlist in his Team London army of volunteers.
Johnson used the planting of the field maple, Acer campestre, in Hillingdon to outline his tree and park programmes over the past four years, paid for by cancelling the Londoner free-sheet and ploughing the £4m into 10 park makeovers instead.
A spokesman for the mayor said the London Tree Officers Association data would be used to help deliver the tree targets.
Percentage of tree cover in the Greater London Authority area, calculated by i-Tree Canopy software - 21.87%.