Of all the driving forces of landcover change examined, the landuses
of Agriculture and Pastoralism are the most consequential. For landcover
change, Agricultural landuse is critical, powerful and influential. It is
critical because it is highly selective. It is powerful because of the highly
sophisticated mechanical and chemical tools at its disposal. It is influential
because the industry is highly significant to the well-being of Australian
society.
Agriculture involves the most dramatic and irreversible transformations
of landcover; from forests or grasslands to croplands. Agriculture, with
its transformation of landcover and its subsidies of nutrients, energy and
water, is by far the most effective landuse to support the ever growing
human population.
There is no avoiding the landcover conversion associated with the indispensable
landuse of Agriculture. We cannot live without it. To live in any way other
than nomadic gatherer-hunters or pastoralists, requires the conversion of
some of the original landcover to crops and pastures. The question is not
whether or not, but how much. Questions about the impacts of Agriculture
on landcover can only be ones of balance. That balance is determined both
by our population size and our need to export food and fibre.
One of Australia's big challenges will be to increase the value of our food
stuff exports, while maintaining or reducing the total area required to
produce them.
The extraordinary characteristic about our society is that we import
people and export food. Obviously that cannot continue indefinitely.
The total area of the landcover of the continent that has been transformed
by agricultural landuse is recorded as (at least) 6%. Satellite images show
the land converted to pastures and crops stretched across the southern part
of the continent and up into central Queensland. The total area of cleared
land looks more like 15%. Lamentably, this figure is not accurately known,
which is amazing for a country that shows great environmental concern.
