Preparing a tree strategy
Trees are an indispensable component of green infrastructure, providing key environmental services such as improving air quality and reducing the urban heat island effect. Yet many are uprooted each year.
Trees absorb particulate pollution, reduce noise by acting as a sound barrier, improve physical and emotional well being, stabalise micro-climates, contribute to biodiversity and can add economic value to areas.
Action should be taken at a strategic level to debate and champion the planting of large canopied trees because of the environmental services they provide.
At the city level a city-wide strategy can review all urban trees, as an important component of green infrastructure, and draw out issues and opportunities for their management. Such a strategy would form an important steer for the local development framework as part of its evidence base.
Urban forestry has evolved as a viable practice in the USA with several cities developing comprehensive urban forest strategies, including the urban forest in Portland, Oregon and New York City’s Million Trees project. These initiatives are supported by tools such as i-Tree, developed by the USDA Forestry Service, which helps communities quantify the structure of community trees and the environmental services they provide. CAVAT (Community Asset Value for Amenity Trees) provides a methodology for valuing London’s trees as assets rather than liabilities and is increasingly being used by London boroughs.
A report for Communities and Local Government, Trees in Towns II, calls for a comprehensive tree strategy as the starting point for a modern, planned approach to tree management. This needs to be integrated and embedded into local development frameworks and other relevant policies. There is further guidance from Trees in Towns II within this site’s advice on managing urban trees. The London Tree and Woodland Framework is an example of a successful tree and woodland strategy which has been integrated into local policy and attracted funding for active tree management at a strategic level.
Trees are a source of products that can be used elsewhere in urban areas. Sefton Council has a dedicated workshop, working with adults with learning difficulties, which uses timber from its woodland and urban tree management activities to make products such as benches, signposts and rubbish bins. These products are then used within its parks and countryside areas. This not only saves the council money but reduces emissions from transportation.
Tree strategies will need to be tied into debates about subsidence and risk management. Trees are often blamed for building subsidence. Climate change is unlikely to change the spatial extent of damage from this hazard but the intensity and frequency of cases may increase. Given the value of trees within the green infrastructure system, solutions need to be found and could include:
- maintaining and pruning trees appropriately
- not building on highly vulnerable soils
- ensuring that buildings on vulnerable soils have adequate foundations to allow for trees within their proximity.
The London Tree Officers Association has produced a risk limitation strategy for tree root claims.
CABE and Urban Practitioners
with the cities of Birmingham, Bristol, Leeds, Liverpool, Manchester, Newcastle, Nottingham and Sheffield