Most Royal Parade trees at end of their lives, flagged by council

Most of the century-old elm trees on Royal Parade bordering Princes Park are expected to die within one to 10 years, with locals fearful after a woman was fatally crushed when a tree collapsed on her on Monday morning.

Melbourne City Council's tree mapping system shows two elms in the same area where the woman was killed are marked "dying", meaning their life expectancy is less than one year.

A 2005 council report found the trees would start dying between 2015 and 2020.

Emergency workers on the scene at Princes Park in Parkville where a tree fell, fatally crushing a Reservoir woman.Credit: Carolyn Webb

Some of these trees are observed to be leaning, a characteristic arborist Craig Hallam identifies as a risk factor for falling. Another leading arborist believes underground construction works could be a factor in the tree's collapse.

Associate professor Allison Milner, a 36-year-old mother of two from Reservoir, was found shortly before 8.30am, peak time on the popular exercising and walking track in Parkville.

Construction workers renovating a nearby university building were the first on the scene and tried to help Professor Milner before she was taken to Royal Melbourne Hospital in a critical condition. She died shortly after.

Runners and walkers stared in shock as they were directed around police tape that had been put up around the site.

Jogger Beth Koch, 33, said she felt for Professor Milner's family. "It could have been any of us,” she said.

Ms Koch said she worried about falling branches on windy days “but it probably doesn’t play front of mind.”

Brunswick student Georgie Sutherland, 21, jogged around the park with her dog every day and said she was now concerned about the stability of the other trees.

The tree that fell in Princes Park, killing a woman.Credit: Carolyn Webb

“You hear of trees falling on cars, but you never expect this to happen," she said.

“It makes me question how safe it is to run through here.”

A tree marked as dying by Melbourne City Council leans towards the walking track on Royal Parade.Credit: Yan Zhuang

The collapse of the 106-year-old tree was the second fatal tree falling in four days in Melbourne and has raised concerns about tree management in the state.

Robert Mineo, senior arborist at Monash Council and Council Arboriculture Victoria chairman, said an English elm could live for up to 300 years if left in nature. But being in an urban environment such as beside one of Parkville's major arterials could restrict the trees' life expectancy to about 100 years.

The tree was one of 3000 elms and 77,000 trees in the City of Melbourne tree register.

Drought combined with ongoing construction works and development projects has meant the Royal Parade trees have been exposed to tough growing conditions, and Mr Mineo said that for these reasons, the City of Melbourne should have been keeping a close watch on these trees.

The council said the row of trees was last inspected on July 12 this year and that investigation concluded the now-fallen tree was not at risk.

"If a tree poses an immediate risk it will be removed.

A Google image from 2017 shows the tree before it fell, killing a woman on Monday.Credit: Google Images

"We remove approximately 800 trees per year for a range of reasons including risk across the municipality," City of Melbourne chief executive Justin Hanney said in a statement.

He said trees in the council area were inspected at least every two years.

Mr Mineo said elms were typically a stable tree. While he did not want to comment on the fallen tree's condition without examining it himself, he said the fall was likely to have been caused by decay or structural compromise as a result of underground construction works.

While all development projects are required to report their plans to the council, Mr Mineo said this often did not happen and root systems could be compromised.

"Sometimes works happen that council doesn’t even know about like NBN or Melbourne Water or roadworks. Councils should know about all these things, but sometimes these contractors do what they do and they should be telling us. Sometime they do, sometimes they don't."

A 2005 council report said the council inspected the trees annually and also noted the Royal Parade trees – as well as those at St Kilda Road, Victoria Parade, Fawkner Park and Fitzroy, Treasury and Carlton gardens – were declining in health and could start dying between 2015 and 2020.

"The long-term sustainability of the avenues will require proactive management involving removing sections of the avenue trees and replacement with new 5-6 metre trees grown off-site," the report said.

But Mr Mineo said inaction on behalf of Melbourne City Council was unlikely as they are often referred to as a benchmark when it comes to tree management.

"I'd be very surprised if inaction has caused this or they've dropped the ball somewhere."

Arborist Craig Hallam said his consultancy company is one of many employed by councils in Melbourne to assess high-risk trees using a raft of technologies – X-rays to examine the trunk, dynamic sensors to look at the base, and radars to scan the root plate.

Mr Hallam said danger signs included cracked branches or trunks, leaning trees, one branch joining another and freshly turned soil around the base of the trunk. People should report these conditions to their local council, he said.

But he said most trees fell due to high winds and it was near impossible to predict which would drop, as each tree varied greatly in structure.

In 2015, the Victorian coroner cleared the City of Greater Bendigo of liability following the death of a four-year-old girl killed by a falling tree branch.

Coroner Phillip Byrne made eight recommendations including that all councils have a computer-based inventory of trees they are responsible for, as well as formalised tree inspection protocols and a higher level of qualification for arborists completing the inspections.

Mr Mineo said the coroner's report would look into whether the City of Melbourne Council had adopted these recommendations.

RMIT Associate Professor in sustainability and urban planning Joe Hurley says Melbourne council is "hugely proactive" in managing urban canopies and that these deaths represent "rare and isolated" events.

"It is time for us to reflect on how we manage trees, but we need to respond in a careful and strategic focus.

"From my point of view, it would not be a good reaction to tragic, isolated events to then have significant reduction in what is a critical infrastructure in cities."

Senior lecturer in urban planning and design at Monash University Dr Liz Taylor said the focus of tree management in Melbourne, and supported nationally, is to increase the tree canopy in urban environments.

She said there needed to be a balance between the risk of injury from fallen branches and trees, against the many benefits of tree coverage – keeping temperatures down in summer, lowering the risk of flash flooding as well as improvements to mental and physical health.