09 June 2011
Life on the edge
When you think of threatened species and endangered eco systems, you think of exotic animals in lush jungles or flora in remote pristine wilderness. In reality, 50 per cent of threatened species and 40 per cent of threatened ecosystems are in urban fringe zones.
Professor Michael Buxton in Wyndham Vale, a rapidly developing area on Melbourne's western fringe.
Post-bushfire peripheral living
Victoria's 2009 bushfires served as a starting point for RMIT researchers Nigel Bertram and Gretchen Wilkins, who led a large team of people at RMIT's Urban Architecture Laboratory to investigate design issues raised by the fires. The project also provided an opportunity to broadly re-think the limitations and possibilities of community life within bush environments on the fringes of Australian cities.
In the final project report introductions, Bertram and Wilkins said that the Black Saturday bushfires wreaked most of their damage in the north-eastern hinterland of Melbourne's greater metropolitan area. The communities there exist in an overlap zone of low-density peri-urban settlement, physically detached from and culturally distinct from the city, but still reliant on the metropolis for jobs, services and visitors.
Bertram says: "The affected region plays a number of roles on a regional and urban scale. The north-east ranges are Melbourne's primary water catchment, with their high rainfall and dramatic topography providing many weekend tourism destinations, alternative lifestyle options, and fundamental water infrastructure supporting the lives of millions.
"As such, the forests, watercourses and other infrastructure of the region are important not only to local communities but crucial to the functioning of the city as a whole."
Wilkins adds: "The work started with a series of questions, galvanised by the tragedy of the fires, including: What does the annual cycle of fire-danger mean in terms of sustainable (endurable) living in such places? How can we plan better and more strategically understand our inextricable relationships with each other and with the city as a whole?"
Research started by looking at what exists: how land has been used and settled in this area over time, the types of infrastructures and landscapes (formal and informal) that have developed to support private and community life.
"We were also literally looking at what remained after the fires: scarred bushland, concrete floor slabs and remnant infrastructure, emergency housing around football ovals, temporary buildings and makeshift town centres; all imbued with a strong sense of community resilience," Wilkins says.
Design projects ranged from landscape interventions on the scale of a township to architectural strategies for individual properties and structures. Bertram sums up: "Ultimately the project was about rethinking the role of the rural periphery and its relation back to the city, from a personal to a regional scale."
RMIT's Professor Michael Buxton is researching peri-urban (peripheral non-urban) areas which include many of these threatened species and ecosystems. Peri-urban areas are very significant for cities as they are important repositories for natural resources.
Buxton says that historically cities and towns are established in the most biologically rich areas. "Cities are located near rivers, harbours and abundant supplies of fresh water, fertile soil, timber, food and other natural resources. This is why people want to live in or near urban areas."
Peri-urban areas extend from the outer metropolitan edges for up to 150 kilometres. In Victoria they are the state's second most productive agricultural region. They include Melbourne's water catchments and extensive tourism and recreational areas - from the Surf Coast, to the Dandenongs and the Yarra Valley.
"In peri-urban areas, human needs often clash with natural values, so conflict is in-built from the start," Buxton says. "Successful and sustainable cities this century will be those that relate to their hinterlands and broader peri-urban areas. Cities that do this well will retain their thriving agriculture, biodiversity and landscapes, as well as resulting in more innovative and healthier, happier humans."
For example, food is a huge issue in the 21st century, with demand increasing but supply becoming restricted. Therefore retaining good quality soils near cities for growing food is extremely important. "Building over good alluvial land in peri-urban areas is extremely shortsighted. We need to keep our options open and optimise these areas," Buxton says.
In the past there have been some good planning decisions for Melbourne and the state of Victoria, as well as some bad mistakes, he says. "In the 1970s there was excellent regional planning work done which resulted in areas like the Dandenongs, Yarra Valley and the Mornington Peninsula being protected - areas which Melbournians still enjoy today. But in recent decades, Melbourne's Green Wedges - the city's lungs - have been constantly threatened, with over 4,000 dwellings constructed there.
"This liberalised approach to urban and rural planning saw developments bursting out of the growth corridors anywhere and everywhere. No one kept tabs on development decisions, which were made on a case-by-case basis and which ultimately led to no policy at all."
Now the Melbourne 2030 policy is aiming to stop this incremental, ad hoc approach to development and the destruction of the green wedges.
The research by the RMIT team has reviewed national and international policies in peri-urban areas and has helped shift official thinking. Seven local councils have formed a Peri-urban Group and state and commonwealth governments have commissioned and funded RMIT research into population development and natural resources use, particularly in the water, agriculture, land use and biodiversity sectors, to discover the trends, drivers and pressures on peri-urban areas.
The team's current project is comparing two scenarios. One continues current trends to 2040; the other is an alternative scenario which retains natural values while increasing populations modestly. "Continuing current trends would lead to the loss of many of the attributes of the peri-urban areas which people value most. The alternative scenario is less costly for councils and essential for Melbourne to exist as a sustainable city," Buxton says.
Other research by RMIT's Dr Sarah Bekessy is investigating biodiversity in Melbourne's urban fringe. One ecosystem in danger is the basalt plains grassland west and north-west of the city. "As well as being a unique ecosystem, it is also a key growth area for Melbourne. If action isn't taken, we will lose species and possibly the whole ecosystem," she says.
Bekessy brings a background in conservation and biology to urban planning and policy issues, which results in very practical research and a different way of looking at issues. "Current conservation tools tend to look at National Park type settings rather than urban fringe areas, for example, whether a new National Park should be located in a particular area.
"This type of decision is relatively simple, as it usually involves one or two decision-makers and a limited number of conservation actions. In the urban fringe there are multiple actors and stakeholders, as well as multiple actions and uncertainties," Bekessy says.
Actors in urban fringe areas can range from builders and developers, to agricultural interests, from town councils to lobby groups. Scenarios are extremely complex and could involve a range of initiatives including offering incentives, market-based strategies, offsets, biodiversity banking or regulation.
"The multiple uncertainties only add to the difficult mix. Urban fringe areas are riddled with uncertainty, are often under-surveyed and offer poor quality data to base decision-making on," she says.
For this leading-edge research, Bekessy and her team have received grants from the Australian Research Council, including through her membership of a new ARC Centre of Excellence for Environmental Decisions and through the Commonwealth-funded Applied Environmental Decision Analysis Research Facility. Industry partners on the projects include local and state government, a catchment management authority and a property developer.
One decision that confronts urban fringe planners is how to detect threatened species accurately in surveys. Survey information is often variable and when consultants tender for survey work the cheaper and not necessarily the best bid wins. Research by Bekesssy and Dr Georgia Garrad has developed a more rigorous process for detecting threatened plant species in the urban fringe.
"The resulting 'detectability curves' can be used by government agencies to determine the likelihood that surveys will find threatened species if they occur on a site. This approach has been taken up by the Commonwealth Government in its advice on threatened species," Bekessy says.
Other research outcomes include maps of Melbourne's biodiversity hotspots, analysis of the risks and benefits of "offsetting" biodiversity loss, and modelling urban growth scenarios for the Strategic Assessments that the Commonwealth Government is conducting under the Environmental Protection and Biodiversity Conservation Act.
Ultimately, RMIT research in urban fringe zones will result in more sustainable cities that benefit everyone, including threatened species.
This story was first published in RMIT's Making Cities Work magazine.