It is quite likely that our grandchildren will never see or experience the Australia our own grandparents loved and venerated - the Australia of Lawson, Heysen, Wright and Roberts.

By the end of this century it is possible that Australia will be gone for good, immersed in a green tide of alien vegetation, pests and shifting climatic regions. It may well still be sunburned and afflicted (more frequently) by drought and flooding rains, but the quintessential Australian landscape that has defined this continent for millions of years and was the backdrop to both Aboriginal and European settlement, will largely no longer exist.

The cancer that is slowly, subtly and remorselessly robbing us of Australia is both metastasized and far advanced. Each year we discover, on average, another 30 alien species of plants and pests which have somehow eluded our vigilance and become established, each wreaking its own particular havoc among the native plants and animals that first arose here and on our industries.

In the deserts which embrace three quarters of the land mass, two South American grasses - gamba and buffel - are transfiguring the spinifex and saltbush landscapes that dominate the continental heartland into a roaring fiery furnace that native plants cannot endure. In a decade or so, visitors to Uluru will have only a Latin American landscape to enjoy.

In 2010, a fungal killer known as myrtle Rust (Puccinia psidii) exploded down a 2000-km corridor along the east coast, attacking eucalypts, callistemons and melaleucas. More than 100 species of native tree, the very architecture of the Australian bush, are under threat - as are enterprises such as the nursery and garden, forestry, bee, zoo, native fruit, cut flower and plant oil industries.

In 2007 Asian bees (Apis cerana) made landfall at Cairns, Queensland. Five years later they have spread out and Australian governments, meeting in conclave, decided there was no point in trying to exterminate them.

The Asian bee is highly aggressive and is likely to have a major impact on native bees and other pollinators of native flowers and to accelerate weed invasions. Over time this could re-work the native landscape - both plants and animals - profoundly.

As the ''green tide'' of invasives rose higher, the Commonwealth permitted the nation's only dedicated research centre opposing it, the Weeds CRC, to fizzle out. Its heavily amputated successor, the Weeds Research Centre, is about to lapse. The Plant Biosecurity and Invasive Animals CRCs were both recently renewed, but only for five to six years.

Beyond there will be nobody, at national level, to co-ordinate the resistance to invasion, especially by plants.

The impact of this invasion will be compounded under climate change, in which CSIRO predicts that 80 per cent of Australian landscapes will be modified, some of them beyond recognition to today's eyes.

This shift in climatic regimes will open up more native ecosystems to incursions of weeds and pests.

From every Australian city and many gardens, a new tide of invaders - all those tough ''drought-resistant'' grasses imported as trendy water-free landscaping during the Millennium Drought - is poised for a fresh lunge at the native environment.

From past experience of invaders like Chilean needle grass, they will overwhelm vast swathes of native grassland and agricultural pasture - and will require a chemical holocaust to control.

From the narrow immediate perspective of government, controlling weeds and pests appears like pouring money down a black hole.

This is why, against the advice of experts, they deemed the Asian bee's extermination ''no longer technically feasible''.

In the Orwellian parlance of modern government what they actually meant was ''not a political priority''.

To hell with the unborn grandkids - they don't speak to Newspoll.

To hell with the quintessential Australian landscape - it doesn't have a vote.

To hell with Tom Roberts and Hans Heysen, nor do they. Let the thousands of invasives that are queued up at wharves, airports and container depots around the globe come and immerse the place. A future generation will have the headache of dealing with them. Glad it's not me.

If that seems a harsh characterisation of our present national attitude, it is nevertheless the likely outcome of our continued neglect and underfunding of weeds, pests and biosecurity in general. It is time our governments understood this.

The irony is that Australia was once an undisputed world leader in the science and art of biosecurity. We had, and still have the crumbling ramparts of, a very effective early warning, quarantine and invasives control system.

Spurred by rude invasions of rabbits, prickly pear and other shocks we developed the expertise to understand and check these invaders, as described in a new book Biological Control of Weeds in Australia by Mic Julien, Rachel McFadyen and Jim Cullen. This recounts the spectacular successes of a century of scientific warfare against more than 90 invasive plants. (To call them ''weeds'' tragically understates the billions of dollars in damage, lost livelihoods and spoiled landscapes they inflict.)

At $180 a copy, Biological Control of Weeds in Australia will probably not be on every politician's bedside cabinet. Yet it should be. It deals with the invasion of our land, Australia, by alien lifeforms - an invasion which they are winning and which we, our descendants and the native Australia, are losing.

The book is also a testament to the mastery of the science of biological control which this country has been a leader in and now, when it is needed more than ever in our history, is systematically dismantling, while hoping that nobody notices. In horse racing we nurture our winners and send losers to the knackers: in science policy, however, we habitually pursue the opposite course. Where we have international expertise and a mountain of hard-won knowledge and skills, we let it atrophy.

Biocontrol is an elegant, affordable way to check invaders. It can maybe spare some of our landscapes from extinction beneath the ''green tide''. It uses knowhow, rather than costly poisons, to achieve its ends. It is a thoroughly practical, Australian solution to the biggest mixing of species in the history of life on Earth, unleashed by travel and trade in recent centuries. If governments, federal and state, the people and the powers of science do not see this, and if they do not now invest in a permanent scientific centre to fight invasives then, quite simply, they do not care if their homeland is invaded, its native landscapes and species transformed or lost, its Australian character forsaken.

But maybe their grandchildren will.

Julian Cribb is an Australian science and agriculture writer and author of The Coming Famine: the global food crisis and what we can do to avoid it (UCP 2010).

The book Biological Control of Weeds in Australia will be launched on April 3 by John Kerin. It is published by CSIRO Publishing. http://www.publish.csiro.au/pid/6509.htm