Key point
1	Tim Flannery: Aborigines had the ability to care for land which enabled them to conserve and protect the flora and fauna, especially through their fire management practices. Europeans had no understanding of the land and treated it as treasure trove of goodies instead of a fragile environment and also stopped the traditional owners from caring for it.

David Bowman:
We know that Europeans have had a devastating impact on the Australian environment mainly through land clearance and habitat destruction. Nonetheless, changes in the timing and frequency of landscape burning following the breakdown of Aboriginal fire management also had a dramatic effect on habitat conditions in areas that have not been cleared. For instance, in some places rainforests have expanded but in others they have retreated. In many areas of Australian grazing country trees have expanded into large grassy plains as a consequence of years of abuse by overgrazing and the resultant absence of fire. In other places excessive burning has degraded economically and biologically valuable forests. These and other changes are linked to the different land management that accompanied European colonisation of Aboriginal lands. In my mind it is just like acquiring a property with an elaborate garden and sacking the gardener - it is inevitable the garden changes.

Jeremy Russell Smith:
In Northern Australia especially it's only recently that we've begun to understand how important traditional management practices were, and still are, for preventing devastating fires regularly spreading uncontrolled across the landscape and, as a consequence, obliterating many fire sensitive species. If people don't burn in the early part of the year or when conditions are favourable, the fires will come anyway, and potentially far more destructively.

2

Tim Flannery: The displacement of Aboriginal people by Europeans has led to a cessation of regular burning regimes which has allowed the build up of fuel loads leading to intense bush fires. This changed fire regime was the primary cause of the extinction of medium sized mammal species earlier this century.

Steve Morton:
It's more complicated than this. European settlement resulted in a chain of events, each of which probably contributed to the extinctions. Other simultaneous changes that took place included greater grazing pressure from stock and feral animals such as rabbits, and the introduction of predatory foxes and cats. Removal by grazing of the habitat of a bandicoot, for example, or the destruction of bandicoots by introduced predators, could expose species to extinctions. Perhaps changed fire regimes played a part, but there is ample reason to believe that these other factors were critical.

I see little evidence to support Flannery's theory that the demise of Aboriginal burning practices has had a dramatic impact on mammal persistence. It is almost certainly true to argue, as Tim has done, that burning in the Quaternary changed certain vegetation types and made them more suitable for some animals than others. However, not all of the inland vegetation types can possibly have been burnt frequently by Aboriginal people; for example, the saltbush country, which rarely burns but from which just as many species have disappeared since European settlement as from those vegetation types that do burn frequently. Hence, I am more convinced that the problem stems from predators and from habitat change brought about by grazing.

David Bowman:
Although understanding the role of fire is critical to effective land management it is remarkable how little is actually known about Aboriginal burning patterns prior to European colonisation or even during the last 200 years. Limited available evidence does support the importance of Aboriginal landscape burning in creating habitat mosaics for small mammals and that intense fires since European colonisation have homogenised some habitats.

However, the widespread extinction of small mammals, particularly in arid environments, appears to be mainly due to the introduced carnivores, which ate them (e.g. cats, foxes and dogs), and herbivores which competed for their food (e.g. rabbits, sheep, goats, cattle, donkeys, horses and camels). Practical experience has shown that introduced carnivores must be controlled for the successful re-introduction of small mammals and it is no coincidence that many remaining strongholds of small mammals are on predator-free islands.

Attributing the extinction of small mammals solely to the breakdown of Aboriginal burning does not explain why the Australian monsoon tropics has seen few mammal extinction in spite of clear evidence of changed fire regimes. In any case, European colonisation has not always resulted in intense fires. In some places it resulted in the near complete cessation of landscape burning because of the removal of fuels due to overgrazing.

John Benson:
There is some evidence that early European settlers burnt more frequently than Aborigines while elsewhere fire as suppressed then reintroduced to keep fuel in check. Flannery did not take into account the impact of the introduction of exotic species like grazing animals and rabbits and foxes. The wholesale clearing of land was the main factor in the destruction of their habitats and their ultimate demise.

Jeremy Russell-Smith:
Certainly, fuel loads do develop through lack of burning with a potential consequence for the development of intense fires. However, lightning does intervene, especially in the tropical savannas. The issue as it relates to extinction of medium sized mammals is nebulous.

Indigenous burning created a patchwork mosaic of country where vegetation/food resources for these smaller mammals would have been available in a range of successional stages. One can therefore anticipate that the patchiness / diversity of resources in the landscape would have been magnified, and may have resulted in increased carrying capacities overall. But how did these mammals fare before the fire-stick? ...obviously, very well!!

Dr Flannery's solutions to the crisis include...
1	Tim Flannery: Mimic Aboriginal firestick farming practices with modern technology, to prevent wholesale destruction by huge bushfires

David Bowman:
Successful management of bushfires demands that we all learn more about the fire regimes of the pre-colonisation period. Clearly we need to understand current Aboriginal fire-usage in places like Arnhem Land where traditional culture is strong. This knowledge can help us design and reintroduce appropriate fire regimes into the Australian bush.

Rampant weed infestation and people living in or close to bushland are serious practical impediments to routinely managing land with fire - this is where modern technologies may help.

It should be remembered that Aborigines leading traditional lifestyles had a different relationship with fire than Europeans. Unlike Europeans, Aborigines did not establish settlements that required protection from fire and unlike Aborigines, Europeans typically view fires as purely destructive and vainly attempt to suppress them. Until Australians work through the complex ecological, social and indeed psychological issues involved in accepting the fundamental place of fire in the Australian environment 'bushfire disasters' will remain a recurring social blight. Australians must accept that fire is just as characteristic of the bush as the smell of gum leaves and that living in the bush means learning to live with fire.

Jeremy Russell-Smith:
I think we would want to take a more realistic approach, addressing individual management situations with appropriate management responses. For a start, Aboriginal land management varied/varies from region to region, for example between northern and central Australia, and so you cannot generalise.

The people of Western Arnhem Land were/are evidently generally conservative in their fire management practices, using fire extensively and at different times of the year to suit different purposes, and as a consequence much fire-sensitive vegetation has survived well, at least until now. Burning conservatively is a real art and there are some indigenous people in Central Australia who are absolute masters, knowing where fires will go, how long they will burn and where they will stop. In other contemporary contexts, however, the management issues are often quite different. For example, pastoralists (both indigenous and non-indigenous), could use intense fires as a simple management tool to control woody plant growth but are mostly too frightened to do so.

John Benson:
Apply fire regimes to different habitats that will maintain biodiversity. Frequent fire will lead to the extinction of species in many habitats. Science should be used to underpin the management of vegetation.

Steve Morton:
This is certainly a beneficial idea, but one must ask whether it's the most important thing to do with scarce conservation resources. I'd be investing effort in working out how to control cats and foxes, and how to bring grazing pressure down to a sustainable level.

2

Tim Flannery: Develop a population policy for Australia based on environmental sustainability.

David Bowman:
Clearly the human population on the Earth cannot continue to grow in a cancerous-like fashion without destroying our life-support systems. However, I feel that calls for any Australian population policy must recognise that the Australian economy is strongly inter-linked with the global economy. We export food and other primary resources to many other countries. It is by no means certain that controlling the Australian population will necessarily protect and preserve our environment because habitats may continue to be destroyed and farmland abused to balance our trade. By simply focusing on Australian population levels the issues becomes trivialised and more importantly can be used for mischievous political purposes such as focusing on the ethnic or racial composition of immigrants - policies that have no place in the civilised world.

Steve Morton:
I completely agree with Tim. The only rider I'd attach is that one has to be politically realistic; I don't see much chance that proposals for a dramatic decline in the Australian population would gain acceptance at present.

Jack Caldwell:
Global population is still growing and will probably reach 10 billion during the coming century. However 4 points should be noted.

• The limitation to 10 billion is a result of fertility decline almost everywhere - some of it surprisingly steep. Any more rapid decline could be achieved only by coercion, which I regard as unacceptable.
• Thereafter, population numbers will almost certainly decline, perhaps for the rest of human history.
• The best informed agricultural studies show that we can feed this population with neither famine nor irreparable damage to the earth's resources.
• Almost half of the world's population now lives in countries where the birth rate is already below long term replacement level.