i-Tree Eco

During Summer and Autumn 2018 City of Trees completed the biggest i-Tree Eco survey outside the United States, with the aim of quantifying the value of Greater Manchester’s trees and woods.

Delving deep for data

Data such as such as tree species, width, height and diameter were collected from more than 6,000 trees across Greater Manchester by a team of 57 surveyors who visited nearly 2,000 plots.

The data was fed into the i-tree software system, which processed the information to provides insightful results about the economic value of trees, trees under threat and where there is potential to plant more.

Headline results

The key results are as follows:

  • There are an estimated 11,321,386 trees with 15.7 per cent of Greater Manchester beneath tree canopy
  • The total annual economic value of air pollution filtration, stormwater attenuation and carbon sequestration in Greater Manchester’s trees is £33,298,891
  • Approx. 1 million trees are in danger of being lost in Greater Manchester due to pests and diseases such as Ash Dieback and Horse Chestnut Bleeding Canker
  • Greater Manchester’s trees act as a filtration system for harmful air pollutants – removing 847 tonnes of pollutants each year.
  • They assist with excessive storm water, intercepting 1,644,415 cubic metres of storm water run-off per year.
  • They sequester 56,530 tonnes of carbon each year and the current carbon of all the trees in the region is 1,573,015 tonnes.
  • It would cost over £4.7 billion to replace all Greater Manchester’s trees
  • They produce 122,450 tonnes of oxygen each year
  • The most common species of tree in Greater Manchester are Hawthorn, Sycamore and English Oak

A greenprint for GM

This data will be used to protect existing trees, as well as identifying new land for planting – assisting with initiatives such as The Northern Forest and the Greater Manchester Spatial Framework - providing guidance for planners and developers.

The results form part of All Our Trees: Greater Manchester's Tree and Woodland Strategy which can be found here.

For more information please contact Bryan Cosgrove at City of Trees – 0161 872 1660 or email bryan@cityoftrees.org.uk


The i-Tree Eco project has been supported by United Utilities, Viridor, Forestry Commission, Oglesby Charitable Trust, Environment Agency, Salford City Council, Woodland Trust, Heritage Lottery Fund, The Greater Manchester Forest Partnership and The Greater Manchester Combined Authority