In South East Queensland, many of our most sought after residential addresses (Laurel Avenue, Chelmer; Abbott Street New Farm; Yabba Street, Ascot) and most of our popular urban retail & dining streets (James Street, New Farm; Oxford Street, Bulimba; Little Stanley Street, Southbank) are lined with large shade urban trees with canopies that reach across the street.
While the visual impact of great urban trees is easy to understand, many of the other benefits they provide are not generally considered, health and social benefits, economic benefits, climate and environmental benefits, safety benefits and engineering benefits. In fact for the countless list of benefits, trees in our urban environments are extremely undervalued.
Most often our urban trees are seen as an afterthought to good urban design rather than a valuable piece of urban infrastructure on par with street lights, sewer lines and stormwater devices. Many Local and State Government Authorities, who have the final approval on the design of our public urban environments, raise concerns about tree roots, the dropping of leaves and fruit, reliance on water and general ongoing maintenance. All of these concerns have resulted in a reluctance to invest in great canopy trees in our cities. We would argue that the broad list of benefits far exceed the concerns. It seems the Australian Federal Government is of a similar realisation – having recently unveiled their plan to increase the amount of urban tree cover in Australian cities, each decade up to 2050.
Unfortunately, our urban settings can be very harsh environments for our trees to survive. The design of great streets and cities prioritise and carefully plan for the inclusion of successful urban trees, considering room for root growth, soil volume, soil composition, drainage and water requirements. For councils, deciding on where to direct expenditure in order to improve a street, planting trees can give the best return as trees can transform a street more easily than any other physical improvement.
If you are weighing up the ongoing maintenance cost of a tree in an urban environment and you are not sold on the exhaustive list of benefits, just consider the economic benefits alone.
Calculating the value of urban trees
In a study by the National Heart Foundation of Australia, the environmental and property value cost benefits alone have been calculated at $3.81 for every $1.00 spent on urban tree planting and management.
In a study of “The benefits of Adelaide’s street trees” presented at the 8th National Street Tree Symposium, a four-year-old tree was estimated to generate a gross annual benefit of $171/ tree, consisting of energy savings, air quality improvements, stormwater management, aesthetics and other benefits. It has been suggested that this value is actually closer to $424/tree. Older, larger urban trees can provide up to 60 times greater pollution reduction benefit than smaller trees through pollution reduction, the storm water control, the cooling effects through transpiration, the housing values and the street pavement stabilisation.
Our Challenge to you!
If we want great streets in our urban communities, we need to start working collaboratively with our local councils, arborists, engineers and soil scientists, to think more holistically about our approach to planting large urban trees in our urban streets and cities. Decision makers in our Local Authorities need to believe that there are design and management solutions that balance maintenance and services so we can encourage the healthy growth of broad canopy trees in our streets.
We call on all State and Local governments to support the Federal Government latest plan for greater “urban canopy”; to advocate for generous tree planting and landscaping in our urban environments; to recognise that the social, environmental, economic and aesthetic benefits of urban streets and cities with large canopy of urban trees vastly outweigh any maintenance and lifecycle concerns.
Three key takeaways
1. Remember that all “Great Streets need Great Trees”, so always advocate for urban trees
2. There is more to establishing great urban trees than simply planting them in the ground, great trees need early planning and design collaboration between design disciplines
3. “the best time to plant a tree is 20 years ago, the second best time is today”