Nick Rogers's leafy suburb is ground zero in Australia's battle over trees - ABC News & Headlines – Australian Broadcasting Corporation

As we build more homes to tackle the housing crisis some worry trees will become collateral damage. But as our climate changes, isn't now the time we need trees most?

Nick Rogers was working from home when it happened. Outside his window, several hard-hatted men appeared at the base of a robust red flowering gum. "I thought, well, they're just doing the annual trim," says Rogers, a middle-aged architect from Melbourne. "Then they began to chop down the entire tree."

At some point, Rogers, outraged about the destruction of a tree that had watched over his street for decades, stood up from his desk, joined the men wielding chainsaws on the nature strip and tried to act casual. He wanted to know who had sent them. By the time they had downed tools, an activist was born.

The story Rogers tells goes like this: he discovered the local council was suddenly enforcing a policy that he claims no one knew they had — removing established, healthy street trees to ensure roads are free of overhanging branches below 4.5 metres from "curb to curb" rather than just the centre of the road. Now standing in council's way is a plucky group of residents led by Rogers who possesses the ability to build a sassy website and organise. They're demanding consultation and a policy rethink to save what they consider their suburb's greatest asset: its trees.

The community campaign Save Banyule's Trees might seem insignificant. One note in the constant cacophony of tussles between residents and local government playing out across Australia on any given day. But a reckoning over trees is looming. The future of our cities, their liveability, their ability to ameliorate heat, their ability to improve our wellbeing is at stake. And Rogers's leafy Melbourne suburb, Heidelberg, is ground zero. 

When the Melbourne City Council assigned trees email addresses so residents could alert them about maintenance issues, they instead received messages of love and camaraderie addressed to the trees. Thousands of them — so many it made headlines worldwide.

"Dear Rose Gum, Over the past year I have cycled by you each day and want you to know how much joy you give me" and, "You are just outside my work and you make me happy :)" and, "Dear Moreton Bay Fig, You are beautiful. Sometimes I sit or walk under you and feel happier. I love the way the light looks through your leaves" and so on.

Everyone loves trees, I'm told by urban planners, arborists and researchers. Yet they go on to say everyone loves trees until they block a view, break a pipe, upend a foundation or stand in the way of development.

In Victoria, trees are the nucleus of so much neighbourly conflict the state's dispute settlement centre says it receives, on average, around 2,500 enquiries relating to tree disputes per year. The centre tells me the only dispute type more voluminous than trees is fences. The Victorian Law Reform Commission even spent several years inquiring into how neighbourhood tree disputes should be dealt with legally, although its recommendations have never been implemented.

Beyond neighbour disputes, councils have struggled to curb illegal tree removal and vandalism on private and public land. The fight has been heated along Sydney's coveted waterfront, where hundreds of trees from Mosman, to Castle Cove, to Monterey, to Brighton-Le-Sands, to Lane Cove, have been cut or poisoned in the name of a sea view. 

Most of these cases go unsolved; perpetrators are hard to identify, yet last month a gardener was fined $187,500 for the illegal removal of nearly 300 trees in a Lane Cove case, which the local council dubbed "the worst act of environmental vandalism" in the area's history.

But a new fault line over trees is emerging. As governments push to densify Australian cities, some worry trees are becoming collateral damage at a time when we need them the most — as our climate changes.

Since the industrial revolution and the slums that followed, trees' significance in cities has been recognised, says Dr Joe Hurley of RMIT's Centre for Urban Research. What emerged as a push for the "garden city" is now being articulated differently, says the professor of sustainability and urban planning.

These days, trees are being labelled infrastructure. "Saying, actually, this is not just a nice to have, it's an infrastructure that's critical in the same way that the wires are that bring us the power, that the pipes are that bring us the water and take away the effluent, that the roads are and the rail are that enables our movement," Hurley says.

Canopy trees are one ingredient in a broader green infrastructure movement, where vegetation is re-introduced to cities via roofs, facades, streets and parks. The greening aims to combat the urban "heat island" effect, improve air quality, support biodiversity, help manage stormwater flow and improve citizens' mental wellbeing.

Governments and planners are increasingly measuring "canopy coverage" — which Hurley defines as "the area of cover that the crowns of trees have in urban landscapes" — to assess tree abundance and guide targets for increasing their numbers. These "urban forest strategies" are being rolled out across the country. But will their targets survive the push to build more houses?

One rainy, winter afternoon I meet Rogers near Heidelberg's red brick train station. He points to the hospital across the road and says that, during World War II, train carriages were modified to ferry wounded returning soldiers from the city to the hospital. On such an austere day, it's possible to imagine the ragged, broken men disembarking at what was then the edge of Melbourne. Theirs was the generation that built the postwar suburbs with large backyards, often peppered with trees, that now holds a swathe of the city's tree canopy.

Banyule council, which encompasses the Yarra River's serpentine curves in Melbourne's east, implemented an "urban forest strategy" in 2023. It aims to achieve 30 per cent canopy coverage across its suburbs by 2050, and 45 per cent across footpath and local roads, with no loss in areas that exceed that target. Council estimates have current canopy coverage at 29 per cent, spread unevenly between its wealthier suburbs, sitting at 40 per cent, and its traditionally more working-class areas, sitting at 15 per cent. Council points out more urbanised areas are lagging behind those with "larger residential lots and established vegetation".

As Rogers walks me through hilly streets, lined with gnarly, towering gums, he outlines the dilemma he believes the city is facing: How will the local council wed its commitment to canopy trees with other policies such as road management? And if they can't do that, then how will they deal with the wave of development heading for the suburbs? "There's not a strategic vision in the council of stitching all the competing parts together," Rogers says.

For its part, Banyule Council says its approach to managing street trees "has not changed". It says it must prune trees or, as a last resort, remove them to keep 4.5m of clearance on "any part of the road" (a 2025 council report says "over traffic lanes"). Debating the finer details of road clearance and tree pruning might seem foolish, until the conversation turns to where canopy trees will grow in a more urbanised city. 

When a mature street tree is removed, it is replaced with "at least one suitable tree to support council's long-term canopy objectives" a council spokesperson said. Yet canopy trees take decades to reach maturity. The time spent waiting, without trees providing the same benefits, is known as "canopy debt".

"The local council is squeezed from state government just saying 'densify, densify, densify'." Rogers says. "And then the state government's planning department has a very laissez-faire, non-prescriptive way of rolling out densification." The area is one of Melbourne's 60 designated activity centres, and some areas have been rezoned for medium and high-density housing between six and 16 stories.

Banyule council says the "more significant issue for canopy outcomes" is the state's streamlined planning controls for townhouses and mid-rise developments up to six stories. The council says it has also advocated for more lenience when it comes to tree pruning around electrical wires — something the state government has previously rejected.

Rogers pauses beside a temporary chain-link fence. On the other side is a construction site, where a row of black and white townhouses is nearing completion. It has replaced a house on a large block with multiple trees. 

"We're going to lose most of our large trees on our blocks that have been zoned for medium density housing, which is going to make our cities a lot worse," he says. "And what comes along with that is there are then applications to take down trees that get in the way of car access onto medium density properties and that's always given priority. We're going to end up with these barren hot suburbs that are going to be unpleasant to live in."

Last year, the Victorian government introduced regulations to enhance protections for the city's canopy coverage. Removing large canopy trees on residential land requires  approval and in some instances replacement. Some critics concerned about tree loss say planning provisions don’t include minimum requirements for deep soil and permeable surfaces, which they see as crucial for the health of canopy trees over time.  

But exactly how trees thrive is complicated, says Dr Greg Moore, a senior research associate at The University of Melbourne. "Trees are remarkably resilient," the horticulture expert says. "If you don't have deep soil and you don't have the tree roots exploring a much larger volume, then you probably need a permeable paving. If you've got a permeable surface, then you probably don't need to have as deep a root mass. So, I don't think there's a simple answer to this."

Still, he says a fight for space, above and below the ground, is taking place. "You're battling to have sufficient space above ground in many places for the canopy to achieve its full potential, but you're also battling for space below ground, particularly in public spaces such as nature strips that are now being used for all sorts of utility services."

YIMBY Melbourne argues the solution to the battle for space is to plant more street trees. "Building more homes is not without tradeoffs," the advocacy group says on its website, "densification of our city's under-utilised land will require the removal of trees from private backyards in order to build new, denser buildings for people to live in." They're calling for 60 street trees to be planted per 100 new dwellings.

The HIA, Australia's residential building industry peak body, says canopy coverage provisions are "challenging" and "can reduce development efficiency, lower housing yield and, in some cases, make projects unviable to proceed". It's calling for "industry to determine the most appropriate response for each site" and for canopy coverage to be focused on the public realm.

The HIA also raises concerns about the costly maintenance that canopy trees require and questions whether they are needed on residential land. While "tree canopy can help reduce urban heat", they say, are canopy tree requirements on residential lots an "effective way of reducing urban heat"?

So, could we do away with our backyard trees?  

"The future of the outdoors is at stake," Hurley says. Creating liveable, resilient cities, he argues, is about getting the right mix of canopy coverage between private and public space. "The most important benefits around urban cooling, biodiversity, mental wellbeing come from an abundant, distributed urban forest."

Both Hurley and Moore argue the public realm alone can't sustain the number of trees cities need. Trees cool not only by shading, but through evapotranspiration, Moore says.

"We don't have enough streets and parks [even] if we fill them all full of trees … to actually provide the green infrastructure that would be part of a really vibrant and healthy city living," Hurley says. The 30 per cent target that many councils have set couldn't be reached by relying solely on public space, he adds. "So, the private realm is very fundamental to canopy cover."

Thirty per cent canopy coverage is considered the bare minimum to substantially lower daytime temperatures. "Studies say we actually need at least 40 per cent canopy cover to substantially lower daytime air temperatures," RMIT urban planning expert Thami Croeser has previously told ABC.

Canopy coverage decreased in Greater Melbourne between 2014 and 2018 by about 0.3 per cent, Hurley's research shows. Elsewhere, a 2022 evaluation of Adelaide's canopy coverage found it decreased by around 10 per cent in a decade. And recent data shows Greater Sydney's canopy coverage increased by 0.2 per cent in a year – at that rate it would take more than 250 years to reach the city's ambitious 40 per cent coverage target.

Melbourne's decrease isn't only caused by development, Hurley says. Changes to backyard use, from adding pools or garages or removing a tree for a view, were a major factor. "Where we see the loss — and the loss in most cases outweighs the gain — is in areas with higher base canopy cover in the private realm."

Hurley argues that we don't have to accept that we must choose trees above housing, or density over trees. "We cannot let ourselves accept that as a binary choice," he says. There is another way: it's about densifying differently, he says — deciding where to densify, and what forms that will take. He questions why we are willing to lose vegetation for developments which give us very little additional housing, such as subdivisions or renovations. Where vegetation is lost, he says, it should be for maximum numbers of houses.

For a long time, urban designer Leanne Hodyl has considered the question: "How do we make really high-density environments more liveable?" She sees floor area ratios (FARs) –a planning rule that limits the shape of a building on a piece of land — as key. Controlling how much floor area a developer can build, but giving them flexibility in how they build it, can allow space on site for permeable surfaces and soil deep enough to grow canopy trees, Hodyl says. To achieve more green space on sites, she argues, we must not be afraid to sometimes build up rather than out.

In other parts of the world, FARs are commonplace, says Hodyl. But in Melbourne we're "still wrestling with whether they're a useful tool or not".

Without such controls, Hodyl warns, density may not be done well. And she recently released a report advocating for them. "There's a misalignment between the drive of state governments across Australia to just deliver more and more and more housing," she says. "I don't feel that there's enough discussion about what type of housing we need and want. It's been fast tracked, accelerated, it hasn't been properly consulted on, and it's missed some huge opportunities to actually do density well."

Yet for every urban planner warning of impending disaster if density is done poorly, there are groups pushing for regulations, such as FARs, to be loosened.

In Banyule, Rogers holds up a photo of the trees that used to stand a few metres from where we're standing beside a row of townhouses under construction. He maintains he's not a NIMBY. He doesn't have a problem with density, he says, rather "with the way we do density". "We will strip mine our cities for amenity and then we'll look back at them in 50 years and go how did that happen?"