DO WE REALLY WANT TO LIVE IN TREELESS SUBURBS?

Paul Harding 2010

As a landscape architect working in Local Government I am continually amazed by residents who don’t want a tree in front of their house, even if they have west facing windows and especially not a gum tree.

Trees have suffered from some bad press and fear mongering lately – bushfire, storm damage and the ever present leaf litter. As part of the natural environment they can be unpredictable and sometimes dangerous and, unfortunately in the current age of human control, often represent an unacceptable hazard. Most people like trees, but just not in their backyard, or even outside their house on the street.

The benefits of trees are numerous and far outweigh the infrequent dangers. However I understand that it would be foolish to trying telling this to someone who has just had a large tree come crashing through their house in the early hours of the morning during a severe storm, but we should be careful of throwing the baby out with bath water.

What would our suburbs, our urban and rural landscape be like if there were no trees?  

Green Infrastructure

Aside from their scenic value and shade, the benefits of trees in the urban landscape have been empirically assessed, in Australia and overseas, as improving community health and wellbeing, sequestering carbon in exchange for oxygen and adding to biodiversity by providing habitat for birds and other animals. A large mature tree can significantly reduce temperatures, mitigating the Urban Heat Island (UHI) effect, reduce heat build up of cars in parking lots and even increase the life of bitumen with their shade; all this for the price of the tubestock, some TLC and water and then little or no ongoing cost. Why wouldn’t you want a tree in your street?

However, pressure to house an increasing population in individual homes has lead to a reduction in block sizes and put pressure to expand residential development into productive farmland. There is less and less land for trees to grow and it isn’t just the space above ground that is important, trees have roots and these need room to grow to support the canopy above.

Sustainable Development

Providing economically and environmentally sustainable housing involves more than just buildings. Along with developers there are many design professions, including planners, engineers and architects involved in the delivery of housing and suburban developments and these interests sometimes have conflicting aims and objectives. Landscape architects in both private practice and local government often need to have excellent negotiating skills and a good appreciation of the diverse interests involved to ensure the needs of trees are well catered for.

Creating spaces for trees requires early intervention in the planning process in regards to lot layout and road verge widths. It is also important to consider at what stage of the development the trees shall be planted ensuring the best chance of survival and of course selecting appropriate species for the size of the street and the function is vital. It is also important to consider the location of underground services and base material used for pedestrian and vehicle pavements that will allow root development without compromising these pavements. There are a number of types of structural soil and pavement systems that allow this.

the Role of Landscape Architects

Landscape architecture embraces a range of skills appropriate to the development of sustainable settlements including residential housing and suburbs.

Landscape architects may undertake an early site analysis of the topography, vegetation and other features at a proposed location to assess the opportunities and constraints of the site which might include an assessment of the carrying capacity so as not to compromise valuable agricultural land.

Landscape architects may influence lot layout and the location of open spaces or easements for stormwater detention. This usually requires a balancing act between the economic values of lot yield and the increased value of lots with advantageous aspects such as access to well designed and managed open space or wetlands.

Landscape architects may be responsible for the design of open space and streetscapes as part of the public domain. As the densities of our cities and suburbs increase, urban parks and reserves will need to serve more people, they will need to be multifunctional and provide a variety of experiences to the users.

Of course all of the above needs to be done on a shoestring budget to ensure houses are affordable and the building industry is viable.
In his address to the Population Australia 2050 Summit held in Sydney last June (2010), the Minister for Sustainable Population, Tony Bourke outlined a triple bottom line that included social and environmental issues along with economic aspects. It may be time to redress the balance in favour of the environment for social benefit.

Paul Harding
Registered Landscape Architect

Paul Harding is a Registered Landscape Architect and has worked for a number of multi disciplinary design firms on a range of infrastructure and streetscape projects and is now employed by the City of Onkaparinga. He has been an active member of the Australian Institute of Landscape Architects for over 10 years and currently holds the position of National Vice President.