Melbourne’s green spaces are being lost in rush to build more housing

By Adam Carey

July 28, 2019 — 11.55pm

Melbourne has lost almost 2000 hectares of tree cover in the past five years as suburban backyards are cleared for new housing.

The amount of urban forest that was removed between 2014 and 2018 is roughly equal in size to Reservoir, Melbourne’s largest suburb by area.

The eastern suburbs, long celebrated for their leafiness, experienced the greatest loss of greenery in that time, accounting for more than two-thirds of Melbourne’s total tree canopy loss, researchers at RMIT University found.

By contrast, the western suburbs have enjoyed a small recent recovery in green growth, although this has been from a much lower base and has mostly occurred on public land.

Residential land provides the largest area of vegetation cover in Melbourne, followed by parkland and public spaces such as streets.

The researchers found Melbourne’s total tree and shrub cover shrunk from 50,964 hectares in 2014 to 46,393 hectares in 2018, an overall decrease in greenery of about two percentage points.

Their report concluded that urban redevelopment and homeowners’ decisions to clear or reduce the amount of greenery in their yards were playing a significant part in reducing Melbourne’s urban tree cover.

Lead author Associate Professor Joe Hurley, of RMIT’s Centre for Urban Research, said the findings were troubling for a number of reasons.

“Trees and vegetation in cities provide a lot of benefits to human health and wellbeing, as well as ecological and biodiversity benefits,” Professor Hurley said.

Trees were also critical to cooling the climate in built-up spaces, he said.

“The big one is heat amelioration, particularly for drier cities like Melbourne and Perth, where we get very hot conditions and it’s only increasing under climate change.”

The report found the amount of tree and shrub cover on residential land in greater Melbourne had declined 1.6 percentage points since 2014, had fallen by 4.6 percentage points in parkland and had increased 0.3 percentage points along street networks.

It said the significant loss of tree cover in Melbourne’s parks required further investigation, but could be caused by some species’ failure to adapt to a hotter and drier climate.

Tree loss was greatest in parts of Melbourne that are renowned for their greenery.

For example, Yarra Ranges Shire on Melbourne’s eastern fringe has experienced tree-cover loss of almost 5 per centage points since 2014, eastern suburban Maroondah has shed more than 3 percentage points of its canopy cover and Mornington Peninsula has lost 3 percentage points.

Outer suburban municipalities of Melton, Whittlesea and Wyndham had bucked the trend and boosted their canopy cover by between 1 and 2 percentage points in that time, mostly in public spaces.

Inner-city councils have similarly experienced modest growth in tree cover.

Professor Hurley said this could reflect a focus by councils in those areas on tree planting.

Some residents have also engaged in volunteer tree and shrub planting on public land to green their neighbourhoods.

Tamar Hopkins is part of the Upfield Urban Forest, a loose collection of volunteers engaged in a “guerrilla” tree planting project along the Upfield railway corridor in Melbourne’s north-west.

Ms Hopkins said she was motivated to start the project after years of “being blown away by the heat island effect” while cycling along the Upfield shared path.

In the past three years the group has planted natives including spotted gums, manna gums, blackwoods, casuarinas, flowering plants and native grasses along the rail corridor.

The effort has required delicate negotiations with VicTrack, the government agency that owns the land.

“It’s about recognising that this is a large piece of land that really could support quite a large tree canopy,” Ms Hopkins said.


Readers should click on the above link to see graphs of what’s happening.

PS: We’ve uploaded the full urban-vegetation-cover-change RMIT report.