Introducing ‘treeconomics’: how street trees can save our cities
As a fight over 11 lime trees in Sheffield, UK, escalates, activists in cities all over the world are making the case for urban trees – to cut pollution, increase land value and even make you feel younger.
Rustlings Road is aptly named. The street in Sheffield is lined with mature lime trees. Their whispering leaves are brilliant green in spring, then cast cool, dappled shade in summer and turn bright yellow in the autumn. But Sheffield city council wants to prune the street, and a dispute about 11 lime trees has turned into a citywide campaign, with more than 10,000 people urging the council to halt its roadside felling. I has also sparked a broader debate about what 36,000 street trees bring to a place that claims to be the most wooded industrial city in western Europe.
This tussle shows how urban trees are both treasured and in jeopardy like never before – beset by disease and spurious insurance claims, and too readily felled by cash-strapped local authorities which only see their potential cost rather than their contribution to climate, public health and even the wealth of a city. Ever since Roger Ulrich discovered in 1984 that hospital patients appear to recover more quickly from surgery in rooms with green views, a growing body of scientific evidence has demonstrated the health – and wealth – benefits of trees in cities.
In Toronto, researchers recently found that people living on tree-lined streets reported health benefits equivalent to being seven years younger or receiving a $10,000 salary rise. As well as studies revealing benefits from everything from improved mental health to reduced asthma, US scientists have even identified a correlation between an increase in tree-canopy cover and fewer low-weight births. And economic studies show what any estate agent swears by: leafy streets sell houses. Street trees in Portland, Oregon, yielded an increase in house prices of $1.35bn, potentially increasing annual property tax revenues by $15.3m.
Despite compelling scientific support for urban greenery, the trees on British streets are imperilled by the lack of any government department or national body to look after them (unlike government-owned woodlands, which are managed by the Forestry Commission). Urban trees stand at the mercy of cash-strapped local councils and a hotchpotch of agencies, from housing associations to highway authorities, who may overlook their true value. But as Sheffield residents mount a desperate defence of their mature street trees, some councils and planners seem to have grasped the value of their urban forest.
Read the full feature from the Guardian here: http://www.theguardian.com/cities/2015/aug/15/treeconomics-street-trees-cities-sheffield-itree