Sarah Priestley is a Street Tree Planner at Wyndham City Council and Chair of Council Arboriculture Victoria. She presented a paper at the 2013 IPWEA International Public Works Conference on ‘Trees and development sites – basic reporting guidelines’. Here she discusses all things arboreal.
How did you come to be working in your current role?
I studied horticulture at Burnley College, which is part of Melbourne University, majoring in arboriculture. I did my advanced diploma and then my degree with Burnley. When I left I started working with a private consultancy, writing reports for developments and building tree inventories and management plans for councils.
I started with local government about four years ago at Bayside City Council managing their street trees, then about 12 months ago I moved here to Wyndham to take on the role as Street Tree Planner.
What does your role as Street Tree Planner at Wyndham involve?
Essentially my role is planning and policy development for public trees. Wyndham is a growth area – we have about 10 new houses going up a week, which mean more streets and more trees required. Council plants its own trees, but also accepts trees from developers, so I determine what species would work here and what we want to achieve from the trees, which also influences the species we choose, and our policy direction and so on.
You presented a paper at the 2013 IPWEA International Public Works Conference in Darwin. Could you please summarise what it was about?
My paper was about managing trees on development sites. The Australian Standard (AS) 4970 ‘Protection of Trees on Development Sites’ was introduced in 2009. It outlines a process to consider trees and is very effective in helping protect them. The paper was discussing that Standard, combined with a bit of a lesson about how trees work.
There are a lot of misconceptions out there about how trees grow and what they need and how they function and so on. The paper went into what can damage trees and how the AS4970 can be used to build a process to protect them.
How has local government management of council trees changed over the years?
Previously it was more likely to be an asset manager with an engineering background managing public trees. Over the past 20 years, however, we’ve started moving towards having arborists manage the trees. These days, every metropolitan Melbourne council has an arborist and I would say at least half of the rural councils have people who are arboriculturally trained.
Does this reflect a shift in the perceived value of trees in our public spaces?
Yes – there are a lot of benefits trees provide that haven’t necessarily been recognised in the past.
Previously there was a ‘just cut it down, we can plant another one and it’ll grow’ mentality. But there are so many benefits of having trees. The cooling of cities – trees can actually reduce ambient temperatures by three to four degrees [Celsius]; they reduce the amount of pollution in the air; they reduce stormwater runoff; there are health benefits around encouraging walking, reducing dust allergies and improving recovery times for hospital patients – there’s all this amazing research that has been done on this. There’s research that trees can reduce violent crime, and that tree-lined streets can reduce the speed of traffic. And there are economic benefits in cooling for houses – mature trees can reduce your cooling costs by about 15 per cent in summer, and can increase housing value by around $20k, and all these benefits increase the larger a tree growns.
In local government, we’re looking after the community, making liveable cities, and trees are integral in doing that, and that’s a relatively new focus. I think people have always loved trees, but those tangible benefits have not always been recognised. And a lot of it is coming from fields outside of arboriculture too, which is giving it a lot more weight.
What does the Council of Aboriculture Victoria do?
The council is a networking group for tree managers in local government. We welcome anyone who has a role in managing trees, it doesn’t matter what their background is and they don’t have to be an arborist. We hold monthly meetings where we have a speaker, and people can place any issues that they’d like to discuss on the agenda as well.
It’s very much a support network, it’s about being able to exchange ideas and connect with other people doing the same job. When I started in local government I found the support provided through meetings and contact with other council tree managers invaluable.
Do you come across any common challenges or issues among tree managers?
A big challenge for us is the competition for space to grow trees, particularly with the emphasis on housing development and buildings. Being living organisms, trees can’t be repaired, so the damage that can occur if trees are not considered during development might result in the loss of trees quite easily. The challenge is balancing that competition for space – you don’t want to stop development of infrastructure, but you want that development to be considered and to work around better outcomes for trees and infrastructure.
The other challenge is that communities can become very emotionally involved with trees. They either love them or hate them, you rarely get a very considered approach to concerns they might have about trees – we’re either doing it all right or all wrong.
The tragic death of a schoolgirl from a falling branch in NSW recently acted as a reminder of the risks that come with public trees. Is this an issue that weighs heavily on council tree planners?
Every arborist, it doesn’t matter whether they work for local government or not, considers that possibility when they look at a tree.
It is a risk that councils manage, we inspect and proactively prune trees and we have a service where people can phone in if they’re concerned about a tree and an arborist will go out and inspect.
Also, while the consequences of falling branches can be catastrophic and tragic, the probability of a tragedy actually occurring is very low. If you think about the number of big trees we have in our environment and how many people play, picnic, walk, fish and live under them, the statistics are about one in 10 million per year. Of course it is still a risk, and nobody wants tragedies to happen.
The perception of this risk can also cause a lot of emotion around species selection. A lot of people have preconceptions that certain trees are more prone to causing problems this than others – I’m thinking eucalypts in particular. Not all eucalypts are the same, they have different branch attachments and they don’t drop branches significantly more often than any other particular tree. Rather, their canopies are a sparser so more of their branches hit the ground. Elm trees, for example, lose just as many big branches in Melbourne, but the branches often get caught up in the canopy on their way down.
Anything else you’d like to add?
Just that if any tree managers out there want to get involved with the Council Aboriculture Victoria they can send me an email at
Sarah.Priestley@wyndham.vic.gov.au