Up to a billion hectares of land are likely to be cleared to feed the world and an area the size of China will probably be covered by cities within 50 years, according to concerned environmental scientists.

And they warn against overconfidence that lost ecosystems can be replaced or restored.

Australian Laureate Fellow, Professor Richard Hobbs, of The University of Western Australia's School of Plant Biology, argues that governments worldwide must think twice before assuming an environment lost to development can easily be replaced.  Professor Hobbs is co-author of an article published this week in Biological Conservation.

Professor Hobbs, a member of the Australian Research Council's Centre of Excellence for Environmental Decisions (CEED), said there had been a lot of talk among policymakers about ‘offsets'.

‘Offsets' meant that if an environment is damaged or lost in one place it was possible to compensate by restoring or protecting an equivalent area somewhere else.

"But the science to date suggests it is very hard to replace a lost environment in another place without a net loss of species," Professor Hobbs said.

"Conservation policies talk glibly about offsets and seem to promise much - but it isn't clear governments really appreciate how difficult and expensive it can be to translocate a whole   ecosystem with all its species and their relationships."

In some cases, offsets were being used to replace centuries-old trees - but newly planted trees cannot provide immediate food or nesting hollows for fauna.

Successful restoration is certainly possible.  Perth's Kings Park is an outstanding example of an environment where restoration has worked well, Professor Hobbs said.

"And the restoration of native vegetation in the Gondwanalink project across WA's Great Southern by reconnecting islands of bush appears to be succeeding in restoring at least some of the flora and fauna.

"But King's Park has thrown a lot of money and resources at its restoration, and Gondwanalink is doing its restoration starting with bare paddocks.  Replacing a good quality intact piece of bush with an equivalent restored area somewhere else is likely to result in a net loss of overall conservation value." 

Professor Hobbs and his co-authors said closer collaboration between policy makers and restoration scientists and practitioners was an urgent priority.

The paper is titled:  "Faustian bargains?  Restoration realities in the context of biodiversity offset policies."

Media references

Professor Richard Hobbs (UWA School of Plant Biology,   (+61 8)  6488 4691
Ecosystem Restoration and Intervention Ecology Research Group)
Michael Sinclair-Jones (UWA Public Affairs)  (+61 8)  6488 3229  /  (+61 4) 00 700 783