What is our urban forest?

Our urban forest is made up of all trees three metres or taller growing within the City on private and public land. The urban forest is owned by the community the City and the State Government, and its management is a shared responsibility.


What is tree canopy cover?

Tree canopy cover is one of the ways we can measure the size of the urban forest. Tree canopy consists of the branches and leaves of a tree. It is not the number of trees, but the amount of canopy cover that has the greatest impact on shade and cooling. This means it’s important to not only plant new trees, but to protect established trees with large canopies because they provide the most benefits.

Why does the City of Stirling need an Urban Forest Plan?

Canopy cover in the City of Stirling is declining. In the last 6 years more than 1.2 million square meters of canopy has been removed and the rate of loss is increasing.

Canopy loss is occurring on private land, City land and State Government land and consequently the whole community must be part of the solution – it is not a problem that the City can fix alone.

The City has set a target of 18 per cent canopy cover but the current rate of loss means that it will not be possible to achieve this unless significant changes are made. 

The City’s Urban Forest Plan describes how the City will work with the community to retain more of the trees we currently have, plant new trees and allow all trees to grow to maturity to provide maximum services and benefits. 


How much canopy cover do we have and how much are we losing?

As of 2018, the City has an average canopy cover of 12.6 per cent. Our canopy is not distributed evenly:  some suburbs and some land types have more canopy cover than others. The map below shows the average canopy cover of each suburb. 


On average, 200,000 square meters of canopy is removed city wide each year.

·  Two-thirds of this loss is occurring on residential land as a result of development and lifestyle factors

·  12 per cent of this loss occurs on City managed land mainly due to development

The remaining 20 per cent of loss occurs on all other land types, including commercial and industrial land and State Government land such as school grounds and along major roads. 

Can’t the City just plant more trees in parks and on verges?

The City is already committed to planting a tree on every verge space where a tree will fit, and as many trees as possible in our reserves without compromising the function of the reserve.  By 2035 we will have run out of places to plant trees, but will still not reach 18 per cent canopy cover due to the tree removal on private land.

Why do we need trees on private land?

Trees provide many services and benefits such as shade and cooling, but this effect is limited to areas close to the tree. In order to reduce the effects of climate change on our homes and to keep them cool in summer, we need trees close to our homes. 
Trees on the verge or in the park nearby will have little to no effect on the summer temperate of your home, but trees in your garden will have a noticeable effect. 

What is the City already doing to grow our urban forest?

The City has been working for many years to protect trees on City land from accidental or deliberate damage, to maintain City trees in the best possible health, and to plant on average 10,000 new trees on verges and in reserves each year.

The City also provides free trees to residents each year to plant in their own gardens, and works with schools to plant more trees in school grounds.

In October 2018, a policy was introduced requiring developments over $100,000 to retain or plant one tree for each 500 square metres of land. 

What further action is the City proposing to take to reduce the removal of private trees?

The City has decided to take a supportive approach to tree retention on private land. Land owners will still be able to remove trees on their land if they wish, but the City will provide opportunities and incentives to retain trees by:

·  Working with developers to ensure their developments can proceed while also retaining existing trees

·  Understanding the concerns that landowners have around trees and finding solutions to these concerns through professional services, information, education and support

·  Rewarding and celebrating landowners who choose to keep trees.  

The City will also:

·  Enable the community to make positive changes to the way that they plant, manage and maintain trees; and to take part in tree-based events, opportunities and learning’s

- Increase the number of new trees planted on private land.

The City already requires new trees to be planted on private land when development occurs – isn’t this enough to increase our urban forest?

No, the new planting requirements are a good start but not enough to replace the canopy being lost.

For example:

Where existing trees are not retained during developments, the City requires 1 new tree to be planted for each 500m2 of land, and developers are commonly choosing to plant small trees.

Based upon a typical development in Nollamara or Balga, after 20 years growth these 2 new trees will have a combined canopy of around 30 square meters. However to allow the development to  occur, 2 or maybe 3 large mature trees with 50 square meters of canopy each were removed.

The overall result is a net loss of up to 120 square meters of canopy and a 20+ year wait for the new canopy to grow.

Who have you consulted when developing this plan?

The City has consulted the community over 12 months to ensure all points of view were heard, including:

·  Four community workshops for residents

·  One targeted workshop for students, and another for the building and development industry

·  Urban Forest Advisory Panel consisting of 18 representatives from key stakeholder groups

·  Interviews with developers and residents with large trees on their land

 - Online survey with 900 participants. 

Why aren’t you introducing rules which prevent the removal of mature trees on private land without permission from the City?

The introduction of rules prohibiting tree removal would be very resource intensive and time-consuming to administer, and would also impact how residents manage their own gardens.  

For example, residents may need permission from the City to remove trees which are near the end of their natural life, to replace their current tree with a different species, or to significantly prune their trees.   Rules could also discourage residents from planting trees in the first place, the very opposite of what we want to achieve.

The City recognises there is a need to raise awareness of the value of trees and to provide education and  support for the voluntary retention of trees before considering or introducing rules mandating retention. This approach provides time for cultural change and for the value of trees to be more widely understood. 

Please see the document 'Options for retaining private trees' for further information on the positive and negative implications of a regulation based-approach to retention.

Why aren’t you introducing rules which prevent tree removal for development purposes?

Such rules could be easily avoided by removing trees prior to lodging a Development Application.
They may also encourage the wide-spread pre-emptive removal of trees by land owners who may want to develop at some unknown time in future.

Pleas see the document 'Options for retaining private trees' for further information on the positive and negative implications of a regulation based-approach to retention.

Will an incentives-based approach actually work?

An incentives-based approach to tree retention will only allow us to achieve the City’s 18 per cent canopy target if the community is willing to engage with the City, to take advantage of the opportunities and support offered, and to voluntarily retain, plant and care for trees in the City.

We will be closely monitoring the success of the incentives-based approach. A comprehensive review will be undertaken after three years to assess the effectiveness of this approach and determine whether stronger measures should be considered.