Australia’s biodiversity under increasing threat from multiple fronts

University of Queensland 19 Apr 11;

New research on the extent of Australia's biodiversity's decline has found that threatened species are impacted by multiple stressors, especially too little — or too much fire, and introduced plants and animals.

Published in the international journal BioScience, the study examines the many causes of threat to Australian species, of which 1700 are considered to be threatened or extinct - and the numbers are rising each year.

Researchers from The University of Queensland found that the loss of habitat through clearing of land and urbanisation is the main threat to Australian species.

However, the majority of species are also affected by other pressures that cannot be eased through the protection of habitat alone.

“Changes to the natural fire patterns and introduced species threaten proportionally more species in Australia than in other countries such as The United States, Canada and China,” said lead author, University of Queensland researcher Megan Evans.

The study also reveals important connections between the distributions of species and threats.

For example, changed fire patterns are a threat to species across almost 90 percent of the Australian landscape, but affect less than half of the threatened species, said co-author Dr Richard Fuller from The University of Queensland and CSIRO Sustainable Ecosystems.

“Even in less populated regions such as Northern Australia, threatened species are suffering from the impacts of too frequent and intense fires, as well as introduced plants and animals – which means that effective conservation management is critical even in areas considered to be untouched wilderness,” said co-author Dr James Watson from the Wildlife Conservation Society.

The authors said it was important to know which species were impacted by certain threats, as well as the spatial distributions of threats, in order to more effectively prioritise investments into conservation management.

“Getting the best outcomes for biodiversity means we need to consider a range of biological and socio-economic factors to decide where to best direct conservation efforts: what threats exist, what are the potential benefits of conservation management, what are the most suitable management actions and how much will they cost?” said co-author and director of The University of Queensland's Ecology Centre Professor Hugh Possingham.

Ms Evans said that the prevalence and incidence of health conditions were commonly considered when prioritising investments into healthcare, and that improved outcomes for biodiversity could be achieved if a similar approach were taken in conservation.

The overwhelming finding of the study is that many of Australia's iconic species are at risk of extinction from multiple pressures, and that careful planning and effective allocation of resources will be required to overcome this extinction crisis.