If there is one thing the pandemic of the past two years has taught us, it is how people value their green and natural spaces, especially in our cities. During lockdowns we crowded our parks, riverbanks, walkways, and bike paths. Fresh air and greenery were an escape and a refuge from the virus.

This is not surprising given that ongoing research has shown how important trees and greenspaces are for human health and well-being. In cities, trees when combined with other vegetation and the soil and water, form what is known as an ‘urban forest’.

Urban forests provide us with areas for exercise, healing and pain relief. They reduce our stress and help us to feel more positive. Beyond delivering such physical and mental health benefits, urban forests build social cohesion from a sense of shared space and neighbourhood connection, which reduces crime and fear.

Research shows that urban forests have even further benefits. They provide us with ecosystem services through cooling and improved air quality. Large trees and accompanying vegetation reduce the heat felt in our streets and neighbourhoods. Trees also capture and filter air pollution.

Our wildlife benefit from urban forests, which provide them with habitat and shelter. Green corridors provide a means for animals, like koalas, to move more freely and safely across our urban landscapes.

Urban planners are becoming more and more conscious of the benefits of urban forests. However, planning and maintaining urban forests is not just about planting a big park full of trees.

Creating the space for urban forests needs to be equitable

In January 2020, Penrith in Western Sydney hit the hottest temperature ever recorded – 48.9oC. Heat waves such as these cause far more death than bushfires and are set to become more common as our climate continues to change.

Flying above the Sydney Basin, it is obvious that Western Sydney has far fewer green patches covering it than more affluent parts of the city to the north, south and east. Research backs up such observations indicating that the leafier suburbs are the wealthier suburbs.

Access to green leafy spaces across many cities, including Sydney, is roughly proportional to household wealth. Many of Sydney’s lower income local government areas (LGA) lack green space buffers.

However, many of the suburbs in these areas such as Blacktown, Camden, Fairfield, Liverpool and Penrith actually have the bare areas available to create green spaces, unlike the City of Sydney LGA which has more bitumen and concrete. There are opportunities to invest in greening these LGAs and some councils are proactively trying to do just this, but more needs to be done.



In a vicious circle, people living in lower socio-economic areas are less able and likely to be vocal and proactive about the need to retain or grow green spaces compared to those from wealthier suburbs. They are also less likely to engage in policy issues which further compounds issues of greenspace inequities.

Such inequity is highlighted in the New South Wales Government’s ‘Greener Public Spaces Premier’s Priority’, which aims to “increase the proportion of homes in urban areas within 10 minutes walk of quality green, open and public space by 10% by 2023”.

The NSW Government has also set a target to increase tree canopy cover to 40% across Greater Sydney. Realising such a goal will require evidence-based understanding and planning. We need to understand the dynamics of tree loss, growth, maintenance and change across our urban landscapes. Such understanding is crucial if we are to plan and meet our targets meaningfully.

Stop the loss of existing urban trees

As our cities grow and expand, our trees and green areas are under constant threat. Development, vandalism, death of young trees, drought and vehicle damage all result in urban tree loss.

Increasing heat with climate change in our cities also affects our urban forests. More than one in 10 trees checked for canopy damage throughout the 2019-2020 summer heatwave that hit Penrith were heat damaged. The cost of replacing these damaged or dead trees was estimated to be $500,000-$800,000.

Often the greatest tree loss happens on privately-owned land. For example, in the North Sydney Council area the greatest loss of trees in recent years has been on private land, which makes up 58 per cent of the LGA.

This issue reflects a failure of governance about how decisions are made for sustainable urban forest outcomes. Such challenges will not be addressed just by providing bigger budgets, more people and having a management plan in place. There needs to be communication and coordination between departments, LGAs, communities and residents.

Start planning new urban forests by applying the 3-30-300 rule

Based on our experience in planning urban forests, we understand that each situation is different and has its complexities. Regardless, we believe the 3-30-300 rule  is a good place to start when thinking about urban forests.

  • 3 trees from every home – which recognises the importance of nearby, especially visible, greenery for mental health and wellbeing
  • 30% cent tree canopy cover in every neighbourhood – which is aligned with how urban forests can lead to coolingbetter microclimatesmental and physical health, and possibly even a reduction in air pollution and noise (Canberra, like many other cities around the world, have set a target of achieving 30% canopy cover)
  • 300 metres from the nearest park or green space – which highlights the results of many studies recognising the importance of proximity and easy access to high-quality green space that can be used for recreation

Aerial photo of Melbourne city

Creating and maintaining urban forests requires good data for decision making

Creating and maintaining urban forests is not something that any city council can do on its own, because much of it is out of their control. Councils manage their street and park trees and can set policy for private trees, but don’t often have the resources to monitor the health of all trees. It takes a village to make and keep an urban forest.

Collecting and accessing data on trees is essential for putting good management systems and plans in place. Council managers need data on tree age, history of plantings, types of species, and the potential canopy space provided by each tree. Councils can then make more informed decisions about the tree assets they have. They can plan 10, 20, 30, 50 years into the future.

Recognising the need for good data, the NSW Government has committed to providing baseline data to councils about the trees that do exist in public spaces, streets and parks. This means when councils maintain their trees, they can update their tree asset inventory with data about tree health, removal, impacts and threats.

Recently, we used our technical, policy and strategic experience to partner with TreeiQ to develop the Greener Neighbourhoods Guide: Guiding Strategic Planning for Urban Forests. This forms an integral part of a Greener Neighbourhoods package for local government recently released by the NSW Department of Planning, and Environment.


Cover page of the Greener Neighbourhoods Guide


The Greener Neighbourhoods Guide provides guidance on how best to understand, plan for, monitor and manage urban forests, and bring the village along on the journey.

The Guide recognises the need to marry planning processes and the evidence that councils and governments need to make good decisions with robust engagement with communities. This means understanding the social nature of institutions and communities and how to embed technical knowledge of the forest and it’s people into the decision-making process.

We are starting to see great examples in Australia, where we are really thinking about integrating tree planning with water, traffic, footpath and street planning. This means that instead of different teams working on street design, they’re working together to create space for trees.

We need to conceptualise trees as essential assets in our urban landscapes, just like we think about footpaths and plumbing. Because there’s nothing else that does the job of trees like they do.


Jan Orton, General Manager, Mosaic Insights

Sophie Moore, Consultant & Western Sydney University PhD candidate, Mosaic Insights

Mosaic Insights is part of the Alluvium group of companies. Mosaic uses insights from around the world to develop ideas and create impact by working on important and challenging projects aligned with community connection, wellbeing, green infrastructure, urban ecology and urban renewal.

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