GREENS MOTION: Urban trees and green open spaces

Mark today moved a motion outlining the importance of urban trees and green open spaces and calling on the Government to prioritise the protection of existing urban trees and green open spaces and to develop a comprehensive urban forest plan for metropolitan Adelaide. The aim of the plan would be to create healthy and diverse urban forests across metropolitan Adelaide, and increase the average tree canopy to 30 per cent by 2045, particularly in those areas identified as being most vulnerable to heat stress.


That this council:

I. Acknowledges the importance of providing South Australians with a diverse range of quality public and private green open spaces and green infrastructure in our urban environments.

II. Recognises that urban trees are critical infrastructure with economic, environmental and social benefits.

III. Notes that increasing the level of tree canopy and green open spaces across metropolitan Adelaide will improve air quality, stormwater absorption, beautify streetscapes and parks, provide habitat for our native wildlife and improved biodiversity.

IV. Notes that South Australia is rated as the second most vulnerable state on the heat vulnerability index and that increasing tree canopy and green open spaces would help cool the city by reducing heat island effect.

V. Notes that between 2013 and 2016 average urban tree canopy cover across metropolitan Adelaide dropped by 1.9 per cent and hard surfaces increased by 2.6 per cent.

VI. Calls on the government to:

(a) prioritise the protection of existing urban trees and green open spaces; and

(b) develop a comprehensive urban forest plan in collaboration with local government and local communities to create healthy and diverse urban forests across metropolitan Adelaide with the aim of increasing the average tree canopy to 30 per cent by 2045, particularly in those areas identified as being most vulnerable to heat stress.

It will come as no surprise that the Greens want to see more trees and green open spaces in our urban environments. Greener spaces make for better urban places. However, the Greens are not the only ones who appreciate and recognise the value of urban trees and green open spaces — their value is well documented.

We know that increasing tree canopy and creating more green open spaces has many positive effects. It can improve air quality by filtering pollutants from the air; lower carbon emissions; absorb and filter stormwater; provide natural cooling to reduce the heat island effect; enhance biodiversity; provide habitats for native fauna; contribute positively to physical and mental health; beautify our streetscapes; and generally improve our quality of life.

Who wouldn't want all of that?

That is why it is alarming to note that in the 2017 report Greener Spaces, Better Places it shows us that we are actually going backwards in metropolitan Adelaide.

From 2013 to 2016, average urban canopy cover across Adelaide dropped from 21.37 per cent to 19.45 per cent. In some local government areas the picture is quite dire. For example, the City of Playford has the lowest canopy cover in the city at 9.4 per cent, a drop of 5.4 per cent since 2009. To ensure that we reverse this worrying trend and increase the amount of tree canopy, especially in the local government areas with the lowest coverage, we need targets.

Our laws go some way to protecting significant and regulated trees but they need to go much further. These laws need to be enhanced to arrest the decline of tree cover and vegetation generally and to stop us going further backwards. At the same time, we must prioritise the creation of more open green spaces across metropolitan areas, whilst also preventing what still exists from being lost forever to development.

The 2017 Living Adelaide report, released under the previous government, recognised this and called for all local government areas to achieve a rate of tree canopy of greater than 30 per cent by 2045. This is similar to the target recently adopted in the ACT. With the average across metropolitan Adelaide at around 20 per cent, this goal aims for a 10 per cent increase across the board, or to put it another way, half as much again as our existing tree cover.

The Living Adelaide report identified priorities that addressed the need for more open spaces, with a focus on "ensuring a diverse range of quality public open space and places". The key priorities include—and I will just go through four of them:

Firstly, planning for diverse areas of quality public open space (including local parks, community gardens and playgrounds).

Secondly, providing diverse areas of quality public open space in neighbourhoods (especially in higher density areas) such as local parks, community gardens, playgrounds, greenways and sporting facilities to encourage active lifestyles and support access to nature within our urban environment.

Thirdly, improving, prioritising and extending walking and cycling infrastructure by providing safe, universally accessible and convenient connections to activity centres, open space and public transport.

Fourthly, ensuring that public open space is adequately greened and irrigated to act as a natural cooling system to reduce heat island effects in urban areas.

Open spaces on their own are not enough: they must be green open spaces. Hard surface spaces only serve to trap in the heat and increase run-off. In 2017, RMIT and the Clean Air and Urban Landscapes Hub produced a research report entitled 'Where should all the trees go?' and that compared national canopy levels overlaid with urban heat and socio-economic data and provided an overall vulnerability indicator. On this measure, South Australia was considered to be particularly poor.

In addition to the 1.92 per cent loss in tree canopy cover and 0.69 per cent loss in shrub cover between 2013 and 2016, there has been a 2.57 per cent average increases in hard surfaces. These hard surfaces include asphalt, buildings, car parks and footpaths. When you break that figure down, it shows that 36 per cent of our urban local government areas have had a 5 per cent increase in hard surfaces over that three-year period, and that is a very worrying trend.

South Australia's rating on the heat vulnerability index shows that we are the second most vulnerable state, after Tasmania. Worryingly, South Australian local government areas make up more than half of the most vulnerable councils in the country. These include the cities of Charles Sturt, Gawler, Port Adelaide Enfield and West Torrens, with the City of Playford being the most vulnerable in South Australia and one of the most vulnerable across Australia. This is due to the loss of canopy cover that I mentioned earlier, and a loss of shrubbery, combined with a 4.5 per cent increase in hard surfaces.

Clearly, we could be doing a lot better. So what are other Australian capital cities doing about this? The cities of Sydney and Melbourne both have detailed action plans to address these issues in their respective cities. Sydney has an action plan entitled Urban Forest Strategy, which was adopted in 2013, and Melbourne's action plan is entitled Urban forest strategy: making a great city greener 2012-2032.

As is apparent from the titles, both these cities have adopted an approach that emphasises the concept of urban forests. Rather than the traditional tree management approach, which is centred on individual trees, this approach focuses instead on the forest. Rather than seen as mere ornaments, trees are treated as critical infrastructure, with their economic value recognised in addition to the environmental and social benefits. Accordingly, maintenance no longer focuses on individual trees but rather on overall forest management.

In Melbourne, the strategy divides the city into 10 precincts with individual plans that identify the existing state of the urban forest in that area. Then, in collaboration with local communities, these plans show how changes will be implemented to create a healthier and more diverse urban forest.

In Sydney, an implementation plan outlines priority actions and achievable time lines, including:

  • protecting existing trees;
  • improving the spread of street and park trees, with a focus on increasing species diversity;
  • targeted programs to increase tree canopy, with an initial increase of 8 per cent over the first 10 years, then a further 4 per cent increase after that; and
  • community education and participation programs.

Some specific actions include:

  • development of a matching grants program that encourages and facilitates community greening programs;
  • increasing the compliance focus to ensure private property owners undertake and maintain the planting of trees following tree removal or development works;
  • ensuring maintenance plans are in place for new trees planted in private development sites; and
  • assessing development applications to ensure proposed tree selection is compatible with desired canopy cover targets, biodiversity needs and landscape character for particular precincts or villages.

The success and progress of these actions are reviewed annually and adapted as required, with a full strategy review after five years.

The Greens would like to see a similar approach taken in South Australia.

It is also important to point out that it is not just the number of trees that counts. Size does matter. The benefits provided by trees increase exponentially with size and depending on the overall increase in leaf area. In one year, one tree cools like 10 air conditioners running continuously. It absorbs 3,400 litres of stormwater and filters 27 kilograms of pollutants from the air.

Aside from the obvious environmental benefits of increased urban tree canopies and green open spaces, there are significant social benefits as well. One of these is the enhancement of social cohesion and physical and mental wellbeing. The 2015 state government report 'Healthy parks healthy people South Australia 2016-2021', which was released jointly by former ministers for health and the environment, the Hon. Jack Snelling MP and the Hon. Ian Hunter MLC, recognised the link between health and nature. The vision was that:

All South Australians experience the health and wellbeing benefits of being connected to nature.

The Greens agree that this is a noble vision. Again, to quote the words of the ministers:

The scientific evidence unequivocally shows that spending time in nature is good for us—it improves our physical and mental health, it has positive effects on our ability to concentrate and learn, solve problems, think critically, and be creative. These concepts, of course, are not new. Aboriginal people have always understood that people and their environment are intrinsically connected, and that the health of one is dependent on the health of the other.

The report refers to the restorative effects of exposure to parks and green open spaces and how this reduces chronic stress, assists in recovery from depression and anxiety, and promotes a sense of wellbeing and an increased feeling of individual resilience.

It refers to strong evidence that green infrastructure, such as parks, gardens, street verges and sports ovals, contributes positively to physical and mental health. Active, healthy lifestyles are also encouraged by access to a range of quality green open spaces in urban areas. As urban areas become more developed, having high-quality green open space to protect and promote population health and the natural environment becomes even more important.

The benefits of tree canopy and green spaces are clear. The current picture in Adelaide shows that there is real room for improvement so that we can achieve these environmental and social benefits. Shifting our tree canopy from the current 20 per cent average to over 30 per cent, while prioritising the creation of more green open spaces, will greatly increase these benefits for all of us.

I would like to finish by sharing a couple of proverbs which I think we would do well to heed. The first is attributed as a Greek proverb and it goes:

A society grows great when old men plant trees whose shade they know they shall never sit in.

The second proverb, which is attributed to China, is:

The best time to plant a tree was 50 years ago. The second best time is right now.

I commend the motion to the house.