Treeconomics is a social enterprise that seeks to highlight the benefits of trees and works to understand how they improve our urban spaces, making them better places to live. Given the number of trees we plant each year, we worked with Treeconomics this year on the data set for Alconbury Weald to assess our projected tree stock for Key Phase 1 and understand its objective value. This was done using a variety of assessment tools and methods, including the most widely used i-Tree Eco model. From this we learnt that once the first phase of Alconbury is complete, the research shows that the 51,130 trees, from 81 different species, will remove over 1.24 tonnes of airborne pollutants, and store over 170 tonnes of carbon, every year. We also found that the projected extent of water held in the tree canopy cover of 24.85ha and then evaporated after the rainfall, will divert 1,630m3 of storm water runoff away from local sewer systems, providing annual discharge savings of £2,500.
This data can now be used to provide further education about Alconbury’s trees, assist with mapping the future benefits of further tree planting across future phases and undertake a gap analysis to help inform which trees are needed to optimise ecosystem services. Given that trees grow with the development so does their replacement value which for the trees within Key Phase 1 stands at £4.8 million.