In 1996, an aerial view of three standard residential blocks in the City of Whitehorse in Melbourne’s middle-eastern suburbs showed about 20 different trees each reaching above roof height and a variety of plants and shrubs on blocks which enjoy around 70 percent tree, grass and plant coverage.
Last year, a new shot revealed that the same three blocks are now 70 to 80 percent covered by dwellings. Two have a tiny backyard with some grass and shrubs. The other backyard has only concrete and a few plants. No tree reaches above roof height (source: Explore Whitehorse).
It is scenarios like this that Melbourne is trying to turn around. In June, 32 Melbourne metropolitan councils together launched the Living Melbourne strategy. This sets out to improve Melbourne’s biodiversity by protecting and restoring existing species habitat, setting targets and tracking progress, greening the private realm, collaborating across sectors and funding urban biodiversity protection and enhancement.
Whilst this is encouraging, more is needed. In coming weeks, the Green Building Council of Australia (GBCA) will hold half-day seminars in Melbourne on September 17 and in Sydney on September 24 which will look a range of biodiversity issues within the built environment. This includes creating natural corridors to allow ecological connectivity; integrating biodiversity throughout the urban fabric; assessing, mitigating and enhancing site ecological value; incorporating nature and biophilic design into buildings; strategies to create habitats which enhance biodiversity on site; incorporating biodiversity pathways in and between buildings; approaches to measure the value of biodiversity and addressing biodiversity challenges at different levels including individual building sites, streetscapes, precincts and cities and regions.
This comes as a new nature category is set to be incorporated into the proposed new Green Star for New Buildings rating tool. This will incorporate elements of both the emissions category and the land use and ecology category in current Green Star ratings.
Under this new category, Green Star credits will be awarded for projects which:
- Protect ecologically sensitive sites and enhance the ecological value of all other sites.
- Adopt design solutions both within and outside the building that foster human contact with nature.
- Reduce the impact of water pollution and runoff on nature through integrated water management solutions.
- Introduce landscaping and other design solutions that create habitats to enhance biodiversity in the area.
- Demonstrate a measurable improvement in ecological connectivity and promotes solutions that encourage wildlife movement.
- Invest in solutions that promote the restoration and conservation of habitats in areas outside the site.
According to Nick Alsop, Senior Manager – Market Engagement at GBCA, urban biodiversity delivers value in several ways.
First there are ‘ecosystem services’ which natural elements deliver to cities and suburbs. This includes improving stormwater quality by reducing runoff, enhancing air quality by capturing and filtering pollutants, helping to mitigate climate change by capturing and storing carbon dioxide and cooling the urban environment and thus helping to reduce both air-conditioning costs and the impact of urban heat islands.
Beyond this, urban nature is beneficial to health, well-being and social connection.
These benefits should not be underestimated. In the US, a study by the US Forest Service and the University of California found that every US$1 spent on tree planting and maintenance in Californian cities returned US$5.82 in benefits. In Sydney, Blacktown City Council found that better shading in streets could reduce annual household cooling costs by $249.14. A study of more than 200,000 Australians aged 45 years and over found that those who had more than 20 per cent green space within a one-kilometre radius of their home were more likely to walk and participate in physical activities rated as ‘moderate to vigorous’. In Parramatta, a study undertaken by the CRC for Low Carbon Living in conjunction with University of New South Wales found that better shading along with several other features could reduce street temperatures along Phillip Street by up to two degrees Celsius.
In his own case, Alsop describes travelling to a meeting at Melbourne University’s Parkville campus on a hot day last summer. Upon entering university grounds with its lush urban forest canopy, Alsop felt thee temperature ‘drop by five degrees’.
In the past, Alsop says Australia has not done well in maintaining urban biodiversity amid perceptions about nature and built forms being in conflict.
Nevertheless, he remains optimistic about the opportunities urban nature provides. More than a third of Australia’s endangered species, he says, can be found in our urban environment.
He says GBCA is trying to help to shift perceptions, attitudes and practices.
“A lot of the work that we are doing is trying to help shift the conversation in the development industry from ‘let’s protect the nature in the corner’, to ‘how do we make this stuff flow through all facets of the built environment,’” Alsop said.
“Urban development offers a lot of opportunities not only to protect nature but also to enhance, expand and enrich nature. What you see running through a lot of the Green Building Council’s work is this notion that nature is just not something you visit in a national park on the weekend – it’s woven through our cities already.
“What we are trying to drive in the property sector, in cities and in planning is that it’s not just ‘here’s this nature in the corner, let’s protect it’, but, ‘let’s bring nature back into cities and let’s see it thrive’. ‘Let’s have a built form that offers building scale, street scale, precinct scale and ultimately whole city scale opportunities to see green infrastructure put in place.”
Vicky Critchley, Senior Project Manager – Environment at Elton Consulting, says Australia needs to shift its thinking in how we integrate biodiversity within our urban environment.
In the past, Critchley says many Australians adopted a separation which saw nature as belonging in the bush and urban environments belonging to people.
Nowadays, this is changing – a phenomenon Critchley attributes to climate change. Concepts such as biophilic design, green roofs and gardens are becoming increasingly common, she said.
Nevertheless, Critchley says, we are a long way from where we need to be whereby consideration of urban biodiversity is ‘business as usual’ across the building sector. Go out into subdivisions and new industrial complexes in Western Sydney, she says, and many ideas about ‘landscaping’ involve little more than adding a few shrubs. Instead, she says we need to think proactively about preserving and enhancing urban nature and biodiversity systems.
Given its social, environmental and economic benefits, Critchley says the importance of protecting and enhancing urban nature should not be underestimated. This is especially the case as nature works best when working as an integrated system. These systems, she says, must be kept intact and enhanced where possible.
Asked about the nature category in the proposed Green Star for Buildings rating tool, Alsop says this aims to promote a holistic approach toward protecting and enhancing urban biodiversity.
This includes going beyond simply protecting existing nature on sites where possible toward strategies which enhance how sites, streetscapes and precincts contribute toward natural biodiversity systems.
As well, the tool seeks to drive stronger connections between people and nature – a phenomenon GBCA hopes will help foster environmental stewardship among those who occupy spaces.
Finally, Alsop says GBCA is trying to promote consideration of how nature on individual projects can form part of a broader patchwork of systems which together help plants and animals to survive and thrive. Take, for example, street trees. Whilst these are wonderful for amenity, Alsop says it is also important to think about the type of food these will offer up when flowering and how these can help birds and animals. Likewise with plants, it is important to think about the different sources of food these can provide for different species at various times of the year.
Alsop says moves to incorporate biodiversity into Green Star enjoy widespread support. Of more than 600 respondents to a questionnaire last year, 97 percent voiced support for the idea of bringing nature back into the built form.
Critchley agrees. She says the new category signals a shift away from simply avoiding damage and protecting existing biodiversity on sites toward encouraging developers to think from a more integrated perspective about what that development can offer to the wider biodiversity network. As well, she adds that there is greater focus on educating building owners and users about how to maintain the natural elements of their building.
Around Australia, natural assets add immense value to our built environment.
To capitalise, we must adopt a deliberate approach toward protecting and enhancing urban nature.