A new report The Nature of Northern Australia** advocates responsible conservation and development of one of the world’s great ecological treasures – the northern Australian tropical savanna. This vast area represents some 25% of the world’s remaining tropical savanna woodlands and is still in good ecological condition, some 1.5 million km2 extending from Cairns and the Cape York Peninsula, through the Northern Territory to the Kimberley in north west Western Australia.
The Nature of Northern Australia is the result of almost three years of intensive research by authors Dr John Woinarski, Professor Brendan Mackey, Professor Henry Nix and Dr Barry Traill
Not only does the north have two thirds of Australia’s freshwater resources, it also contains abundant minerals, energy, unique iconic landscapes, including Kakadu and the Kimberley and unique aboriginal heritage.
Some of Australia’s largest, most undisturbed rivers, an abundance of plant and animal species not found anywhere else in the country, and nationally important areas of rainforest, mangroves and tropical heath lands are also located in the north.
Recent pressures with water supply and drought in southern Australia have refocused national development attention again on the north with a joint government and industry taskforce reviewing options for the future.
“In other parts of the world, tropical savanna is in decline due to land clearing, unsustainable grazing regimes and over population, but this vast area of northern Australia is remarkably intact,” co-author Professor Brendan Mackey from The Australian National University said.
However, there are mounting concerns about the biodiversity assets of this region documented in surveys in the report. Ecological threats such as changing fire regimes, overgrazing, feral animals, exotic weeds and climate change remain unresolved issues.
Scientists have singled out cattle grazing, above climate change and mining, as the most threatening process to northern Australia.
In an ABC interview Professor Brendan Mackey said 70 per cent of northern Australia is held under pastoral lease and cattle stations should do more to protect the ecology of tropical savannas.
“So what pastoralists do or choose not to do will have enormous bearing on the environmental health of northern Australia and its wonderful globally significant natural assets,” he said.
“What we are asking for is for what we call best management practice.”
Despite the difficulties associated with pastoralism in the north the report documents exciting developments at Trafalgar, at Charters Towers.
Joe Landsberg is demonstrating the benefits of ecological grazing in a most difficult environment. He says “we reduced our stocking rate by 60%. Then by spelling at least 20% of the property every wet season, we were able to restore native pasture species to greater than 80% within a few years. These lessons have now led us to our current management regime, where spelling 20% of the property annually, strategic use of small areas of exotic pasture, conservative stocking rates and intensive herd management have increased our productivity (i.e. higher calving rates, earlier and heavier turn-off weights, better meat quality) and therefore profit. Monitoring sites on the property also confirmed the improvement in pasture quality, soil health and water quality. We also have an annual control program for exotic weeds. Current research in natural resource management also confirms these strategies lead to improved biodiversity and ecosystem health. “
Premonitions of intensive irrigated agriculture development in the north have brought back memories of insect plagues and high pesticide use in the sensitive tropical environment.
Professor Henry Nix, another of the authors behind the report with Professor Mackey, says critics of the cotton industry are not aware genetically modified cotton has overcome challenges faced over a decade ago.
He says genetically modified cotton has proved it is sustainable.
“Cotton is regarded as a monster, and it certainly was 10-15 years ago, because of the very large amounts of chemicals – 17, 18 sprays per crop,” he said.
“Now that’s down to as low as one spray. Eighty per cent of their cotton crop is now a GMO crop.”
CSIRO has developed an entirely new 21st century agronomic package for cotton production in the Ord irrigation area using off-season production, transgenic cotton and beneficial insects
Another remarkable innovation for use of the savannas is a practical reduction in greenhouse emissions from a modified fire regime that reduces high intensity late season burning.
The SMH reports that Conoco, which operates a liquefied natural gas plant in Darwin, had entered into an agreement to offset some of the greenhouse gas emissions produced at its plant. In return for carbon credits, Conoco pays the West Arnhem Land Fire Abatement partners more than $1 million a year. Some 100,000 tonnes a year of greenhouse gas emissions can be saved by this approach which is verified by satellite monitoring.
** The Nature of NorthernAustralia – Natural values, ecological processes and future prospects
By John Woinarski, Brendan Mackey, Henry Nix & Barry Traill
2007 ANU E Press Australian National University E Press
ISBN 9781921313301 (pbk.) ISBN 9781921313318 (online)
Read the e-book here: http://epress.anu.edu.au/nature_na/pdf/whole_book.pdf