What Price Biodiversity?

Article excerpt

How do we value something that is rarely traded for its true worth, yet sustains life on Earth? Steve Davidson outlines a collaborative beginning.

Putting an economic value on biodiversity is a complex challenge involving both scientific and economic tools. Yet it is clearly a worthwhile task, and a pressing one.

According to Dr Denis Saunders of CSIRO Wildlife and Ecology, some 192 species go extinct in the world every day. That's 70 000 species lost each year.

To the sceptic who argues that extinction is a normal process, Saunders says the above rate of loss is many times greater than the 'background' rate of extinction, that is, without human interference. Extinction rates today are 100 to 1000 times greater than those in the fossil record. Furthermore, the rate of detrimental change -- at the level of genes, species and ecosystems -- is increasing, not slowing.

Aware that biodiversity is a dwindling and often unappreciated resource, a group of scientists led by Dr Brian Walker and Dr Steve Cork, of CSIRO Wildlife and Ecology is developing principles and methods for objectively valuing biodiversity. The ambitious program is being funded by both CSIRO and the Myer Foundation and involves scientists and economists from some six CSIRO divisions in partnership with state and federal agencies and other organisations. They intend to report their findings regularly between 2000 and 2003.

Ecosystems at your service

Cork says the project is focussing on ecosystem services -- the conditions and processes by which natural ecosystems sustain and fulfil human life -- and which we too often take for granted. These include such services as flood and erosion control, purification of air and water, pest control, nutrient cycling, climate regulation, pollination, and waste disposal.

`People are well aware of the intrinsic aesthetic, cultural and physical values of ecosystems such as forests and of ecosystem goods such as timber,' Cork says. `But we need to raise awareness of ecosystem services, which are very poorly understood.'

He cites the example of clean water. A recent study in the United States showed that the provision of clean water to New York City by nearby forests was equivalent to a capital investment of US$6-8 billion, plus an annual $1-2 billion operating cost for plant. The city decided to maintain water quality by means of ecosystem services instead of the costly technological fix. It bought some parcels of land, applied certain covenants on fertiliser use in the catchment and made a one-off investment of only $1 billion to upgrade local sewerage plants.

An Australian example can be found in the Thomson River catchment which supplies much of Melbourne's water and is logged on an 80-year rotation. An independent economic study of the catchment reached the perhaps surprising conclusion that `an increase in rotation length or a cessation of logging would increase substantially the value of catchment outputs'. In other words, the value of additional water in streams in the catchment would exceed the value of timber foregone if management of the forest was altered.

Productivity to pollination

Before they can `value the nature' the researchers need to determine the nature of ecosystem services. They are conducting a vigorous assessment of the kinds, magnitudes, consumption and, finally, economic values of services in a selection of Australian ecosystems. The aim is to produce information of use to policy writers and decision-makers.

The four case studies will be in Australia's agricultural heartland (the farming zone), the rangelands (a grazed ecosystem), the Atherton tableland (tropical agriculture and forestry), and a southern forested catchment (water and timber).

`In each case, we first intend to sit down with the experts -- local landholders, conservation groups, land management agencies, state and local governments, industry people, federal agencies, economists, lawyers -- and devise a list of goods and services provided by the catchment,' Cork says. …