Photo: Kristian Bell

Imminent collapse of mountain ash forest: choose paper or possum

Mountain ash forest in south-eastern Australia will almost certainly collapse in the next 50 years, according to an assessment to be presented today.

Dr Emma Burns, from the Australian National University Fenner School of Environment and Society, said that assessment, which contributed to the Leadbeater’s possum being ranked as critically endangered, is a huge step in recognising the need for the protection of the mountain ash forest ecosystem.

‘The International Union for the Conservation of Nature Red List of Ecosystems risk assessment was part of 30 years of research that the Commonwealth’s threatened species scientific committee considered when uplisting the Leadbeater’s possum to critically endangered,’ she said.

Dr Burns and colleagues modelled 39 different scenarios and found there was a 92 to 99.99 per cent chance of collapse of the mountain ash forest in Victoria’s Central Highlands by 2067. ‘If there’s a small fire, or any level of harvesting, then collapse in the next 50 years jumps up to 97 per cent. If there’s a large fire – think Black Saturday – then there’s basically a 100 per cent chance of collapse.’

Although threatened species within the mountain ash forest have been acknowledged, the mountain ash forest itself is not listed under any legislation, and thus is not legally recognised as critically endangered by Australian governments. ‘At this rate, there won’t be enough tree hollows for possums to live in – yet our governments still support the native forest logging industry. It’s a matter of trade-offs, and addressing whether you prefer paper to possums. Right now, it’s politics driving policy, not science or evidence-based decisions driving policy.’ Dr Burns said there is still a critical window where we can act to prevent the loss of the mountain ash forest ecosystem.

‘Preventing further harvesting, expanding our conservation and restoration actions, and further investment in research and management to mitigate fire risk could see this system recover within our children’s lifetimes. Surely this vital system and the species it supports is worth it?’

Dr Burns’ collaborators on this research were Professor David Lindenmayer, Mr John Stein, Mr Lachlan McBurney, Mr David Blair, Dr Wade Blanchard and Dr Sam Banks, all from the Australian National University.