United Utilities sponsors world’s largest tree survey conducted outside US

United Utilities has helped fund Greater Manchester’s Community Forest, City of Trees, to carry out the world’s biggest i-Tree Eco survey outside the United States.

The water company is one of the key sponsors of the project which collected data from more than 6,000 trees across Greater Manchester.

The data was fed into the i-Tree Eco software system to calculate characteristics of the total tree population including the economic value of trees, trees under threat and where there is potential to plant more.

The results, which City of Trees released during National Tree Week, show that there are an estimated 11,321,386 trees in Greater Manchester and trees in the city intercept 1,644,415 cubic metres of storm water run-off per year. They also act as a filtration system for harmful air pollutants – removing 847 tonnes of pollutants each year. Added to this, 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.

The total annual economic value of air pollution filtration, stormwater attenuation and carbon sequestration in Greater Manchester’s trees is £33,298,891.

The survey was carried out across Greater Manchester this summer and autumn in one of the world’s largest citizen science projects ever, collecting data such as tree species, width, height and diameter.
A team of 57 surveyors visited nearly 2,000 plots to help calculate the environmental and economic benefits that trees provide, as well as highlight any risks to tree health.

Results include:

• It would cost £4,776,020,361 (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

Bryan Cosgrove at City of Trees said: “By putting a value on Greater Manchester’s trees and woods we can ensure they are appreciated not just in terms of their amazing aesthetics but as natural assets providing a wealth of important environmental and economic benefits.”

Jim Airton, from United Utilities, added: “We know trees bring great value not only to us as a water company but also to communities in the North West.  “This survey gives us a better understanding of that value and how we can use trees to solve some of the water issues in Greater Manchester.”

The i-Tree Eco project ‘All Our Trees’ was supported by United Utilities, Viridor, Forestry Commission, Environment Agency, Salford City Council, Woodland Trust and Greater Manchester Combined Authority.