In 2009, the City of Edmonton analyzed the environmental effects, value and structure of Edmonton’s urban forest using the ‘Urban Forest Effects Model.’ This modelling software can approximate the effectiveness of the urban forest in at least three ecosystem services: cleansing the air; sequestering carbon; and, reducing storm water in the City. It relies on monetary values for each service which have been taken from other contexts (benefit transfer method) and can be quite uncertain. But the advantage of this method is that it is comparatively easy to apply.
If done for similar (e.g. North American) contexts it can quickly deliver useful first approximations. For the City of Edmonton, which has 12.8 million trees, it was a sufficiently robust approach to understand, and to communicate to their Council and citizens, some of the additional services offered by trees and how the use of trees can save the City money. Financial benefits were tallied and the cost of their boulevard, centre median and buffer trees calculated, focusing on: structure (species composition, extent and diversity); function (environmental and aesthetic benefits); value (annual monetary value of the benefits provided and costs accrued); and, management needs (diversity canopy cover, pruning needed).
It was found that the average benefit per tree in Edmonton’s urban forest was US$74.73. The cost for caring for each tree is US$18.38 resulting in a net benefit of US$56.35.