SA Weekend cover story: The fight to save Adelaide's disappearing urban trees
They clean our air, cool our homes and provide habitat for wildlife – but our urban trees are disappearing. Renato Castello looks at the efforts, and challenges, in planting the town green.
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On the 15-minute walk to school, Amanda Kenley Chung and her children make sure to look up.
The gum trees that dominate the undulating landscape of their Athelstone neighbourhood in Adelaide’s northeast are perfect habitat for a game of “spot the koala”.
Sometimes the droppings provide the sensory prompt for Athelstone Primary students Matilda, 11, and Harry, 9, that a marsupial is nearby.
The koala count, Kenley Chung says, is a fun way to connect the children with their environment.
“The most we’ve ever got was eight,” Kenley Chung recalls of koala tallies five years ago. “Now we’re lucky to get one or two.”
Kenley Chung believes a factor in their decline has been housing subdivisions clearing habitat – and preferred roosting spots for the marsupials.
Her family lives in a part of Athelstone that was once – in the 1960s and ’70s – considered a risky place to build. But not even the area’s rocky terrain and Bay of Biscay soil at the foothills of Black Hill Conservation Park could stop SA housing developer Alan Hickinbotham’s wish to create a housing estate that respected and maintained as much vegetation as possible.
“Why couldn’t Athelstone become a totally different housing estate with large native trees and creeks, where trees blended into flower-filled bushland…,” the late Hickinbotham reflected in his memoir From The Ground Up.
“Why remove trees for the sake of arrow-straight roads? If trees had to be removed, why not plant others to make up for their loss?”
Kenley Chung and her family moved into their Greenside Ave house in 2008; drawn to the semirural lifestyle and an ancestral link to the suburb.
But today, she is worried that zoning changes, introduced in 2014 as part of a statewide push to increase housing density allowing much smaller blocks, are threatening what she loves about her neighbourhood.
She gets anxious every time she hears a chainsaw. “(Developers) don’t care,” Kenley Chung says. “They are just buying an old house to subdivide and demolish.”
Today, the fast-paced shift towards urban infill – combined with weak laws and an unfounded fear that big trees are dangerous – has experts worried about a widespread decline in trees across most of metropolitan Adelaide.
Blocks are being cleared and trees sacrificed for smaller blocks, while the appetite for larger houses means there is little room for backyards or front yards with trees.
In fact, South Australia is the worst Australian state when it comes to protecting urban trees.
A RMIT study for advocacy group Green Spaces Better Places that compared vegetation in metropolitan councils nationwide from 2013-16 found that SA had the lowest “green cover” in Australia at 56.8 per cent and the second lowest tree cover of 19.45 per cent: an almost nearly 2 per cent fall in three years.
It also found SA’s urban paved surfaces had increased by 5 per cent, while 43 per cent of councils had a “significant loss” in trees.
In the face of scientific consensus about the threat of climate change, councils here and globally are grappling with how to balance urban greening, with urban consolidation.
It’s a tricky balancing act for people like Burnside Council’s environmental assets co-ordinator Ben Seamark.
“It’s a challenge every city around the world’s facing,” he says.
“We recognise trees as being a key element to addressing climate change, it’s probably the best tool to address climate change, but getting that balance with all other needs and a growing population, I don’t think there’s been an answer yet.”
Burnside Council owns and manages some 40,000 public trees including centuries old river red gums in the state heritage-listed Hazelwood Park reserve – where Seamark chats with SAWeekend; it’s an interview that is punctuated by the loud chatter of lorikeets and screeches of sulphur-crested cockatoos.
Seamark reels off the benefits of trees: reducing pollution, providing biodiversity and habitat for native wildlife, making streets and houses cooler, cleaning stormwater, increasing real estate values and improving mental health.
And yet, year after year, residents in his area apply to have them cut down, even though trees are central to the council’s identity and are even symbolised in Burnside’s corporate logo. After all, this is the leafy east.
Burnside Council has among the state’s highest concentrations of public-owned trees but is not immune to the loss of vegetation.
Between 2005 and 2015, the area recorded a 10 per cent decrease in canopy cover, largely fuelled by felling of species on private land.
Three years ago the council increased its tree planting budget by $84,000, more than doubling to 1000 the number of trees planted annually, which Seamark says will only just counter the loss of trees.
“I think generally people don’t really appreciate how hard it is to plant a (street) tree,” he says, pointing out that about 20 per cent of trees planted by councils will die within 30 years.
“You see a space for a tree and then you look at it and you’ve got to look above for overhead powerlines, then got to look below for gas, sewer … so we’re quite limited with the additional trees we can plant purely because of the competing infrastructure.”
The Liberal Government is pressing ahead with a target set by its predecessors to increase urban green cover – trees, bushes, grasses – by 20 per cent by 2045 across most council areas.
Campbelltown Council, where neighbourhoods have undergone significant housing subdivision in recent years, has only 19 per cent of canopy cover remaining and will need to plant at least 23,000 trees over the next 25 years to meet the government’s target.
That means increasing the current annual planting rate from about 700 trees to more than 1000 – or an extra 925,680sq m of green cover, the council says – enough to cover the MCG playing field 52 times.
The absence of trees is most keenly felt in Adelaide’s northern and western suburbs where intense subdivision has denuded neighbourhoods.
Playford Council, according to the RMIT study, has 9.4 per cent canopy cover and has lost 5.4 per cent since 2009.
A separate report for Charles Sturt Council found it had lost the equivalent to 40 football fields’ worth of trees between 2008 and 2015.
Trees, grass and other plants can lower the land-surface temperature by up to six degrees – when compared with paved surfaces – during a heatwave, according to research published by Macquarie Universtity last month analysing heat maps of Adelaide’s western suburbs.
Councils are responding to the challenge by increasing planting budgets, developing tree strategies, and working together to find solutions to the ongoing urban deforestation and mitigate against hotter summers.
They are also trialling species that will tolerate recurrent heatwaves and drought, but still grow quickly, look attractive and won’t damage infrastructure. But it can take decades for a tree to reach maturity, and just minutes to end its life.
Mitcham Council is leading the way in rethinking how it resurfaces roads and replaces footpaths so they can capture more rain for roadside trees and shrubs to survive their formative years.
It has resurfaced 30km of footpaths with permeable paving, which allows water to soak underground and has installed close to 1km of underground soakage trenches to siphon stormwater into reserves and trees.
It has also installed 500 SA-designed and made TREENET inlets – small slits in kerbs connected to a roadside reservoirs – which collect rainwater and divert it to a tree’s roots.
Mitcham Council estimates in a year with average rainfall it captures, or soaks away, the equivalent of 10 Olympic-sized swimming pools – or 25 million litres.
“It’s really not rocket science,” says the council’s sustainable infrastructure engineer, Tim Johnson, of its approach to stormwater management.
Premier Steven Marshall announced in January that tackling climate change will be a major focus this year. Greening suburbs is a “key” priority.
Environment Minister David Speirs, who will have lead role in overseeing this agenda, says retaining trees on private land is critical to that goal.
“The vast majority of open space in Adelaide or in any city is not parks, it’s not our parklands … most of the open space in this city is in people’s backyards,” he says.
“It’s not just trees, we have to think about the understorey because trees alone are only one part of cooling our city and creating habitat.
“We’ve got to get native grasses and shrubs on our median strips, along our pavements, in front yards and backyards.”
The Government will establish a new entity, Green Adelaide, which Speirs says will use the Natural Resources and Mt Lofty Management Board levy to “turbocharge” greening projects and focus on urban ecology.
“I’m going to give it a bold agenda, bold challenge to green this city in a vibrant and ambitious way,” he says.
An announcement on who will spearhead the agency is expected this year.
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The Government is also proposing. as part of planning reforms, to reward developers and homeowners with faster approval rates if they meet higher design standards including planting at least one tree on a subdivided block.
Minimum landscaping benchmarks are also proposed.
“That’s a big step forward,” Speirs says. “People say: ‘Is (one tree) enough?’.
Well, it’s a lot more than what’s required at the moment and the development industry is screaming about that.
“A property with trees around it or as part of the garden is worth more on the real estate market, so there’s a value proposition there as well.”
Housing and development industry groups hate the idea.
The Housing Industry Assocation says forcing new homeowners to plant trees will increase the cost of building, making new homes unaffordable for first-home buyers.
Mt Barker Council’s urban forest officer Chris Lawry says infill is better than continuing to sprawl housing north and south, but argues the present housing policy is at “complete odds” with the government’s aim of creating a “greener city”.
“You’re turning a place at Unley (which had one house) into four or six houses and what happens is every bit of vegetation is stripped from that property and the street tree at the front goes too because of access for a driveway,” he says.
“Infill hasn’t been done well. We’ve dropped the ball; there should be some legislation governing how much green cover is going to be left on a site (before development).”
Lawry, who speaks with infectious enthusiasm about trees, believes that changes to regulated and significant tree legislation, meant to protect old and mature trees, has also accelerated loss of private vegetation. The legislation was introduced in 2000 to prevent trees with a girth of two or more metres, regardless of species, from being cut down or extensively pruned without council approval.
In 2011, in a move then Labor Planning Minister John Rau said was to balance the protection of trees with the need to remove inappropriately located trees, the significant trigger was increased to 3m, making it easier to cut down mature trees.
The amendments also allowed homeowners to remove exotic species, regardless of their size or historic, environmental or amenity value.
Trees within 10m of a house or pool – except for eucalyptus and willow myrtles – or trees within 20m of a dwelling in a bushfire zone could also be felled without approval.
Lawry says the 10m rule has devastated species such as spotted gums and lemon scented gums, which were reclassified in 1995 from eucalyptus to the species corymbia, meaning they lost protection.
He believes the exemptions have made the legislation “near worthless” in protecting trees.
Within a year of the Rau-led amendments Messenger Newspapers reported council outcry that the changes had led to widespread destruction.
Former Botanic Gardens of SA director Stephen Forbes, in a 2018 column in The Advertiser, condemned subsequent Labor governments for diluting the legislation.
“Building safe communities and healthy neighbourhoods is one of South Australia’s seven strategic priorities, which raises the question why the State Government has viewed trees as little more than a liability that create barrier to development,” he opined.
Under legislation, significant and regulated trees should be preserved if – among other tests – they make an important contribution to the character of the area, are an indigenous or rare species and are important habitat for native fauna.
But homeowners can push for a tree to be removed if they can argue that a tree poses a risk to their health or their property.
In 2017, the Government passed a further amendment that allows DPTI to fell trees for major road and infrastructure projects without approval or community consultation. Recent community angst has been levelled at DPTI’s removal of about 180 mature roadside gum trees for a $20 million upgrade of Golden Grove Rd, in Adelaide’s northeast.
Dozens of mature trees are also under threat for the widening of the intersection of Fullarton and Cross roads at Urrbrae – ironically next to the Waite Arboretum.
Mitcham resident Joanna Wells is leading a campaign to have the trees spared and says recent discussions with DPTI have given hope that they may seek to keep the trees and an adjoining state heritage-listed Waite lodge.
“It’s easy to simply trash and burn everything and replace it with a straight line of road – anyone can come up with a design that does that,” the former teacher who is studying horticulture says.
This weekend she and allies will place banners – with the words “How many more, Premier?” – on hundreds of trees in Adelaide and the regions they warn could be at risk from further road upgrades.
“Fewer mature trees and more cars on the road is actually the last thing we need and want,” Wells says.
Planning Minister Stephan Knoll last November quashed calls to reform the significant tree legislation amid concerns the laws are undermining the Government’s and community ambitions to plant more trees.
But Speirs agrees with critics of the legislation saying that it is too easy to cut down significant trees. “There’s a little bit of controversy,” he says, jokingly. “(But) it’s fact.” The Advertiser sought comment from Knoll through his media adviser but did not receive a response.
Seamark, who has a 25-year career in tree management, believes that attitudes towards trees are changing – not necessarily for the better.
Rather he has seen a “big shift” in perceptions that trees, particularly large eucalyptus, are dangerous.
“Studies show people are either highly for or highly against trees – they don’t tend to sit in the middle,” he says. “As blocks become subdivided, you’re basically forcing the potential for more conflict between trees and people.”
Such conflict erupted in Unley in 2017 when a message “It is a crime to kill our trees – SHAME ON YOU” was sprayed on the house of a family who successfully argued for the council to approve the axing of a 21m river red gum in their backyard.
That same year people protested, in vain, to stop the killing of 83 trees as part of the Glenside Hospital redevelopment for a housing estate. Developer Cedar Woods consortium, who undertook the project, says more than 400 trees, many semi-mature, will be planted in the project.
Waite Arboretum curator Dr Kate Delaporte, who looks after 2500 trees, believes society in general does not value what trees do. “It’s always that trees are something to be cut down and to get out of the way … (but) the first thing that should be done when you think of a proposal for a building is: ‘How do we save the tree and build around it?’,” she says.
“Rain is not going to fall if we don’t have trees. We’re going to be a desert and deserts create deserts … it’s that simple.”
Seamark says educating people about trees’ beauty, diversity and benefits will be the only way to change negative perceptions and help protect trees.
“Without it it’s going to be very difficult to manage trees generally,” he says.
To that end Burnside Council in 2018 mapped all its trees on a publicly accessible database allowing residents to click on a tree to learn its species, age, height, circumference and environmental benefits – such as oxygen generation, stormwater and carbon capture.
Each tree has an ID meaning if people are concerned about a tree’s health they can quickly report the problem to the council.
Seamark hopes it may encourage people to feel ownership and connection with the trees in their neighbourhood.
Gardening identity Sophie Thomson says with coronavirus and associated social distancing it is “more important than ever” for humans to connect with nature.
“There is a lot to be said for the importance of connecting with nature and this isn’t just when we go out to a park, it can be in our back garden, back courtyard or even a balcony.”
She says the Biophilia hypothesis – a term coined by US botanist Edward Wilson – suggests there is an inherent community need to interact more closely with the natural environment. Ignoring that, Thomson warns, could have “dire physical, emotional and psychological effects”.
“Many of the health and wellbeing challenges our kids are experiencing, from increased obesity to increased mental issues such as ADHD, can be related to the fact they have too much screen time and not enough green time,” she says.
Kenley Chung has noticed more people walking her neighbourhood since the COVID-19 pandemic forced people to work from home.
She hopes that a positive to emerge from the virus crisis is a greater appreciation for nature and more protection for trees.
“People come to areas like this (Athelstone) because it looks so lovely,” she says.
“But then they see that trees can be messy and they get rid of them – they’re basically destroying what brought them here in the first place.”
*Ben Seamark has recently moved to Tea Tree Gully Council.