Saturday, October 27, 2007

Another One Bites the Dust

The weather is getting much warmer. Shade is so welcome on these hot days. But many of the shade trees that create a luxurious green umbrella over the river valley and among the houses are fast disappearing. One day there is a beautiful old weatherboard house waiting for a new owner, perhaps a lick of paint and care of the old garden and tall trees. And the next day everything is razed.

It's the middle of nesting season. Bats have lost their foraging food sites and flowering gum blossoms. Possums and birds have lost their homes. A tan-furred ringtail lies dead at the side of the road. I feel powerless.

What takes me out of my despondency is the substantial research work that's been done around urban forests and green spaces in terms of human health and wellbeing, along with the dedicated agencies and volunteers involved in promoting sustainable living. In Brisbane and other cities, green architects, designers and landscapers are working to improve and restore urbanscapes to sustainable living environments. For example, according to the South Australian Urban Forest Biodiversity Program (UFBP):

'The UFBP aims to redress the loss of biodiversity in metropolitan Adelaide, thereby enhancing environmental sustainability, amenity and quality of life. Applying biodiversity planning to urban areas is a new approach to achieving the goal of a sustainable future that conserves the region's unique biodiversity - our natural heritage.'

This elegant Brisbane River valley could well be protected within such a UFBP framework. The SA organisation heralds the value of biodiversity outlining that diverse habitats are valued for several significant reasons: (i) their ecosystem services including the protection of water resources; (ii) their biological services including the provision of food and shelter, and (iii) for their social 'services' including recreation and education. The UFBP report cites conservation biologists Meffe & Carroll (1994) who suggest an additional category needs to be included - psycho-spiritual services - as an important values' attribute of diverse urban habitats. These values relate especially to concepts of aesthetic beauty and religious awe.

Meffe and Carroll regard these four biodiversity services as 'instrumental values', that is, they are valued only in relation to their human use. In contrast, they point to the 'instrinsic values' of diverse habitats. They warn that when faced with the potential eco-tragedy of many development projects, it is important to argue for intrinsic value rather than instrumental (anthropocentric) value but will developers and governments accept this distinction and embrace a notion that shies away from economic considerations.

Perhaps another way of arguing for the re-greening of the river valley is to examine the benefits of urban trees. For example, The Southern Center for Urban Forestry Research & Information in the US has produced a booklet listing the benefits of urban trees noting an improvement in people's quality of life, in community amenity and air quality. The booklet states that trees 'reduce stormwater runoff and erosion; they temper climate; they can save energy; they create wildlife habitat; they can improve health, serve as screens, and strengthen community. They can even help contribute to a community’s economy and way of life'.

Other studies show that community involvement in urban forest re-creation and bushland care helps create a sense of community, promotes pro-environmental behaviours and 'enhances a community’s sense of social identity, self-esteem and ownership'. And notably, 'a loss of trees ... can have significant psychological effect on residents'.

Ecological knowledge and awareness of the benefits of urban treescapes are crucial. Action around re-greening will ensure our living spaces are shady, restful and sustainable.

Meffe GK and CR Carroll, 1994, Principles of Conservation Biology. Sinauer Associates, Massachusetts.