News
The magic number to make Perth green again
The need for greener urban environments has never been more pressing. Dr Grey Coupland and Dr Jane Chambers shed light on why we must create greater green spaces in our cities.
“Perth is at a tipping point when it comes to our urban canopy cover,” Dr Coupland, ecologist and leader of the Pocket Forests WA program at the Harry Butler Institute said.
“Without intervention, our city will face worsening heatwaves, reduced biodiversity, poorer air and water quality, and declining mental and physical health outcomes for residents.”
Research has demonstrated that access to nature can reduce stress, improve mental health and enhance physical health by providing the capacity for us to exercise, for recreation and relaxation.
Green spaces also play a fundamental role in promoting urban biodiversity, providing habitats for a range of wildlife, from birds and insects to small mammals and plants.
“They help mitigate urban heat islands, reduce flood risks, and improve air quality by filtering pollutants, all helping to combat climate change at a local level,” Dr Coupland said.
Despite the many known benefits, Perth has the least vegetation of any capital city in Australia and no laws in place to protect trees on private property.
“To preserve the limited canopy we already have, it is essential we introduce laws to safeguard established trees on private property,” Dr Coupland said.
Image: Dr Grey Coupland (third from left) establishing a tiny forest at South Padbury Primary School.
Dr Chambers says this need to intensify development to prevent urban sprawl and create an efficient, liveable city presents a fundamental threat to our biodiversity and wellbeing.
“Current development is causing a loss of tree canopy, loss of open space – especially private open space like backyards – and natural areas. We can have intensification that includes trees and nature, but we need to plan for it,” she said.
Research has consistently shown that contact with nature is essential for our physical and mental health and for child development.
It’s an especially significant issue for Perth, as it is in one of 36 global biodiversity hotspots – areas where internationally significant biodiversity is under threat.
“Globally, these areas support nearly 60% of the world's plant, bird, mammal, reptile, and amphibian species. Many species found nowhere else in the world call Perth home, so if we wish to clear and develop land, we can’t just offset bush and wetlands out of the city – we need to integrate nature into the city,” Dr Chambers said.
“There is currently no holistic strategy or plan, informed by an ecological understanding, to conserve our biodiversity or integrate nature into our city. It is hoped that the Perth and Peel Urban Greening Strategy currently being developed by the WA Department of Planning, Lands and Heritage, will address this.”
The ecologists both agree that a clear target is needed to guide government, industry and community efforts to protect and restore urban canopy. And they have the magic number.
“The 3-30-300 Rule is now seen as a best practice for urban environments,” Dr Coupland said.
The rule was developed by Dutch researcher Cecil Konijnendijk, who has spent 30 years studying the role of trees and green space in cities. It has since become a guiding principle for many governments, cities, organisations, and communities around the world.
The opportunity on our doorstep
In Perth, these spaces can be up to 15 metres wide, presenting a huge opportunity to improve our canopy without requiring additional land.
It’s something the WA Local Government Association (WALGA), which came together with experts for their Urban Forest conference at Murdoch University this week, has recognised.
“Streetscapes provide an invaluable opportunity for greening, encouraging active transport and creating ecological linkages throughout the landscape,” a WALGA spokesperson said.
“Most local governments have verge policies that enable the creation of native gardens on verges, which is a great way to integrate nature into our urban environment.”
These spaces are also the focus of the Woody Meadow Project, which Murdoch PhD candidate Ali Babington has been working on. The project aims to rejuvenate underutilised spaces in urban areas with diverse Australian shrubs and trees.
This approach to greening our verges offers a novel and cost-effective way to introduce quality plantings into our urban landscape for social and environmental benefits.
“We have incredible flora around us that does well in urban areas. If these plants are used in high density with high species richness, we minimise the risk of failure whilst reaping the rewards of integrating more diverse local plantings into our lives,” Ms Babington said.
Image: Murdoch PhD student Ali Babington planting a woody meadow in public open space in Cannington.
This is one of many projects that Murdoch researchers are involved in, with Dr Chambers leading the NatureLink Perth initiative to promote and enhance urban biodiversity and Dr Coupland running the program to plant ‘pocket forests’ across the metro area.
“By investing in urban forests today, we can create cooler, healthier, and more connected communities for generations to come.”
News
The magic number to make Perth green again
Posted on
Harry Butler Institute (HBI)
As experts in the area of sustainable development, the Harry Butler Institute enables industry to deliver maximum economic value to our community, whilst simultaneously safeguarding the environment.