Mountain Ash forest generates nearly all of Melbourne's water. It is
also facing "imminent collapse" due to a radical change in
Australian National University are behind the discovery, with the
release of a 35 year study that provides the first empirical evidence
of the disastrous effects of over-logging.
researcher Professor David Lindenmayer, from the ANU Fenner School of
Environment and Society, says wildfires combined with over-logging
have tipped the Mountain Ash forest "very close to collapse".
of a forest is indicated by marked changes in the condition of an
ecosystem - particularly the rapid decline in populations of key
plants and animals.
of animals living there have halved, and in some cases have declined
by more than 65 per cent during the past 20 years," said
could be avoided by having better forest policy and greater political
will to save the forest's large old trees, Professor Lindenmayer
primary cause of the imminent collapse was the loss of half of the
population of large old cavity trees, which many animals depend on,
over the past two decades. Replacing the lost cavity trees would take
numbers of Leadbeater's Possum, the Greater Glider and other arboreal
marsupial species dependent on these big old trees have dropped by 50
to 65 per cent," Professor Lindenmayer said. "Since 2004,
there have been significant declines in almost all species of
tree-cavity reliant bird species including the Laughing Kookaburra
and Crimson Rosella."
what exactly will happen if the forest collapses?
Mountain Ash trees, which can grow up to 100 metres tall, would
likely be replaced by Acacia shrubs as the dominant plant species.
This would mean a dramatic change in the ecosystem.
Mountain Ash forest generate nearly all of the water for the 4.5
million people living in Melbourne. It also stores large amounts of
biomass carbon and supports timber, pulpwood and tourism industries.
we don't act quickly to turn this dire situation around, we will have
a crisis on our hands," Professor Lindenmayer said.
urgently need major changes to forest policy to rectify this
situation, especially greater protection for large old trees."