Australians have been urged to “act early, act local” to save large tracts of the Australian landscape from shifting into radically-altered states.
A team of 26 leading ecologists from the Innovative Research Universities (IRUs) have released a list of the continent’s ten most highly-threatened environments.
They warn that these are all at risk of reaching ‘tipping points’ where they may change rapidly and irreversibly into alien landscapes, often dominated by introduced or unfamiliar species.
“In ecological terms, a tipping point is a threshold beyond which major change becomes inevitable. It often happens quite fast, such as when a rainforest is destroyed by fire, damaged coral reefs become infested by seaweeds, or invading weeds take over large expanses of savanna,” said Professor Bernie Dell, a sustainable ecosystems expert from Murdoch University.
“When this occurs, it’s very difficult – if not impossible – to restore the original natural system.
“It means that, unless we act with speed and decision, there are Australian landscapes today which Australia’s grandchildren will never get to see.”
The IRU has published “Protecting Australia’s most endangered landscapes”, ranking landscapes according to the extent of their vulnerability and the scale of the threats to them.
Based upon recently published peer reviewed research, it shows that Australia’s ten most endangered landscapes and their main threats, in order are:
1. Mountain ecosystems: threatened by global warming, fire and human impacts.
2. Tropical savannas: invasive plants and animals, huge bushfires, extreme events.
3. Coastal floodplains and wetlands: sea-level rise, human development activity and climate change.
4. Coral reefs: ocean warming, ocean acidification, overfishing, coastal runoff.
5. Dry rainforests: changing fire regimes, hotter temperatures, water regime changes.
6. Murray-Darling Basin: overexploitation, water regime changes, salinisation.
7. Southwest dry sclerophyll forests and heathlands: water regime changes, hotter conditions, extreme events.
8. Offshore islands: invasive plants and animals, extreme events, ocean changes.
9. Temperate eucalypt forests: hotter temperatures and changes in fire and water regimes.
10. Mangroves and salt marshes: hotter temperatures, rising sea-levels, water regime changes.
“Some of these changes are global – but many of them are also local – and can be mitigated by well-planned local action,” said Professor Dell.
His Murdoch University colleague Professor Giles Hardy, director of the Centre of Excellence for Climate Change, Woodland and Forest Health, added: “In the case of northern jarrah forest, which runs from the Perth Hills south to Collie, we need to apply a mosaic of management techniques to ensure its survival.
“Many scientists advocate for a trial of thinning in the forest. The trees are all competing for diminishing ground water and so thinning some of the ecosystem could ensure the survival of this unique and biodiverse habitat.
“The drought deaths of vegetation and the loss of stream flow in the northern jarrah forest is a sharp reminder of the vulnerability of Mediterranean ecosystems in particular to climate change.”
The IRU ecologists warn that in many ecosystems the shift towards tipping points is happening quite rapidly – and remedial action needs to be both prompt and effective.
“Australians naturally love the Australian landscape. It would be a great tragedy if future Australians do not get to see and enjoy it as we have seen and enjoyed it – simply because their parents neglected their responsibility to manage it wisely,” says lead author of the IRU group, Professor Bill Laurance, Australian Laureate and Distinguished Professor of Conservation Biology at James Cook University.
The assessment of the 10 most vulnerable ecosystems was intended as a first step towards a coherent national plan of action.
IRU is a network of seven comprehensive Australian universities, conducting research of national and international standing. The network has national reach, with a presence in every mainland State in Australia and the Northern Territory. Collectively the network operates in over 40 locations, with a focus on outer metropolitan and provincial cities.