Explore Melbourne's
Urban Forest

Age diversity

Like all living things, trees decline in health as they age. Trees that are in poor health are not as effective at providing environmental benefits, such as cooling the city, providing habitat or cleaning the air. If a tree’s health is not expected to improve, it is removed from the landscape to enable a new tree to be planted.

Many of Melbourne’s trees, including those in our iconic boulevards and parks, are well over 100 years old. While they have performed remarkably well to date in faring against droughts, changing climate and urbanisation, their health is declining as they age. Many of Melbourne’s trees were planted at the same time, giving us beautiful landscapes of large trees. Unfortunately, this also means that many trees will decline in health and require removal at the same time. In addition to loss of tree canopy cover and amenity, this can reduce the amount of habitat available for wildlife.

A resilient urban forest features age diversity, with species of varying life spans and growth rates.

Increasing diversity

A lack of species diversity leaves the urban forest vulnerable to threats from pests, disease, and stress due to climate change. Currently our urban forest is dominated by Eucalypts, Corymbia, Planes, and Elms. Many of these trees were planted at the same time during condensed periods of planting activity, and large numbers of elms and planes are now reaching the end of their life.

Reducing Risk

Combined with the substantial losses associated with an ageing tree population, myrtle rust and sycamore lace bug are current threats to the Eucalyptus, Corymbia and Platanus genera. Diversification is a basic rule for reducing risk. A greater range of species will provide greater resilience and long-term stability for the forest as a whole.

The Urban Forest Strategy sets targets to have no more than 5% of any tree species, no more than 10% of any genus and no more than 20% of any family.

Tree planting schedule

Each Urban Forest Precinct Plan contains a planting schedule which shows when urban forest planting will take place in each street over the next ten years. The schedule for planting is based on a range of factors, including community priorities shared in the local precinct workshops.

The tree planting roadmap shows when each street will be planted and what the intensity of the planting will be. In some streets, planting might be minimal due to limited opportunities for new trees, or in other cases tree planting might occur on a large scale as part of a streetscape redevelopment. The map also shows when tree planting is complete in each street.

When prioritising where to plant, it’s important to focus resources in the locations that need it most. This includes consideration of where we have opportunities to plant new trees or replacement trees, where the highest density of vulnerable people reside, which streets are the hottest in summer and where low canopy cover exists today. More detail about the factors considered to develop the planting schedule is included in each local Precinct Plan.

Why canopy is important

Canopy cover represents a way of expressing, as a percentage, how much of any given area is shaded by trees.

The canopy cover graph above shows two potential futures for canopy cover in our streets and parks. The lower line represents what is projected to happen to our canopy cover if we stop planting trees. The line above shows what will happen if we replace trees as they are lost and plant new trees at a rate of approximately 3,000 trees per year to 2040.

Canopy calculations

Canopy cover is a key criterion by which we measure the urban forest’s ability to produce benefits for the community and the environment.

Increasing canopy has been identified as one of the most cost efficient and effective strategies for mitigating the urban heat island effect and adapting to climate change. The City of Melbourne has used lidar and orthophotography to obtain accurate measures for canopy cover across
the city.