The Age of Weeds: Let's declare war before it is too late

Albert the archaeology student was in the Charles Sturt University library, slumped over a heap of palynological textbooks that traced the emergence of the Emmer and the Einkorn on the Fertile Crescent some 10,000 years ago.

He was dozing gently in the spring sunshine when an early blowfly droned past, rousing him from his soporific state, in which a mischievous Morpheus had implanted a sudden question.

The books all said the same thing: That humans had, over a few thousand years or so, harvested wild grasses, brought them back to the home shelter, dropping a few seeds around the place which, over a longish period, selected themselves into a sort of crop. It was the start of agriculture, the start of civilisation, religion, literacy, computers, wars, politics, the cross-your-heart bra, Tupperware, Spandex, the space race, Teletubbies, the whole goddam thing.

And with humans came weeds. Weeds everywhere. Humans spread weeds like they spread, well, humans. They turned the whole of planetary biology topsy turvey and created a problem they couldn't even begin to handle. But Albert had the eerie sensation that he wasn’t getting the full picture. At back of his sleepy head a small question popped up. In a squeaky sort of voice it said, "I wonder if, instead of humans spreading weeds, all the time weeds have actually been spreading humans?"

Feverishly he began to thumb through botanical, palaeontological and agricultural histories. Hour by hour the sun slid down the sky and up again, he searched and cross referred till his eyes stood out on stalks. In the end it was as plain as a pikestaff. Back in good old Pangaea, the weeds had the world pretty much to themselves. They could move around at their ease and do weedy things to one another, colonising any ecosystem they chose. They weren't even much bothered by dinosaurs.

Then Terra Firma played a nasty trick on them: plate tectonics: First Gondwana and Lawrencia, then a whole mass of inferior continental fragments, each a weedy island empire unto itself. For a couple of hundred million years the weeds sat and stewed over it all. Their Garden of Weeden had been taken away and somehow - anyhow - they had to get back again. It was written in the root zone.

It took a long, long time before a misbred chimpanzee stumbled out of the enfolding shelter of the rainforest, scratched himself and took off across the savannah, rock in hand. But the weeds knew a priceless opportunity when they saw one. It took 'em a while, but in the end they managed to breed a particular sort of chimp, clad in the skins of other animals, who was prone to pick up grains and cart them around with him. Instead of humans domesticating wheat and barley, the wheat and barley had domesticated humans.

The weedy strategies for doing this were amazing. They lured humans with luscious fruits. They ravished us with head-spinning scents. They wooed us with nectar. They taught male humans to gather the brightly coloured genitals of weeds and present them to their females as a sign of their true intent.

It wasn't long before weeds began selectively breeding humans on the basis of their ability to transport weed seeds. They started by developing farmers - famed for their ability to cultivate a whole lot of other things by accident besides wheat and barley - but soon they moved on to explorers, merchants, witches and apothecaries.

In Elizabethan times they invented the gardener and seduced him with the rose. They hooked the Chinese on rice. They drove the Dutch crazy over tulips. In collectors, they launched a still-growing and slightly pornographic obsession with orchids.

Then, in the 18th Century, they invented the botanist.

The botanist, as everyone knows, is a compulsive spreader of weeds. He takes a curious plant from darkest Africa and introduces it to Kew Gardens, whence it quickly leaks out to collections, gardens, nature reserves and wildernesses all round the world, takes over and throttles them. He is a bio-terrorist “par excellence”. One highlight of this weedy campaign appears to have been a specimen called Banksia distributor.

Delighted with their handiwork, yet not content with conventional methods of reproduction and human husbandry, the weeds soon fell to genetic manipulation. From the original Banksia they created a host of clones, hybrids and genetically modified strains.

The pasture scientist, for example, who cheerfully collected an innocent native grass in Latin America, where it was doing no-one any harm, and promptly infested half the Northern Territory with it. Oops.

The home gardener - an especially dumb vector - who spreads ecological havoc from his tobacco pouch, after spending a fortnight's holiday in Sumatra, the Anatolian high plateau, the Pampas or Serengeti and dodging AQIS on the way back in. The “TV Back-Yard Renovator”, who can stick more alien species into 20 square metres of dirt in less time than any known animal on earth. Then there is the garden centre owner, ground zero of an ecological holocaust that scatters aesthetic but environmentally disastrous species far and wide across his customer catchment.

It was with the observation that plants actually used beauty, scent and style as techniques for getting humans to distribute them liberally around the landscape, that Albert realised that weeds in fact have a “sense of humour”.

One of their sneakiest tricks is the bushwalker, a sub-strain with a deep admiration of weeds, whose thick woolly merino Explorers and deep-tread Rivers boots are the perfect Darwinian selection for transporting seeds. There is the “Four-Wheel Drive Fanatic” who omits to clean his tyres and radiator, the “Sunday Angler” who leaves aquatic weeds tangled round his prop, the “Flag-of-Convenience Shipping Magnate” who spews foreign algae into other people's waters, and the unmentionable “Gentleman's Outfitter” who invented trouser turn-ups just to cart seeds.

Not content, the weeds engineered the “Gene Jockey”, who introduces precisely selected genes into other plants in a shotgun sort of way that is bound to create new weeds, the “Chemical Salesman” who applies a very precise form of selection in order to breed better and stronger sorts of weeds and the “Environmentalist”, who insists that no herbicides, fire or grazing controls be used, giving the local weeds their winsome way.

After an era of great success and ensuing complacency, the weeds became alarmed. The chimps were putting shopping malls, asphalt and condominiums where weeds used to be. They were taking over the world. They had to be taught a lesson.

Weeds had experimented with humanicides back in the dark ages. But, apart from Socrates and King John - if a surfeit of peaches counts as a humanicide - hadn't had famous success. The smart money was still on moving the seed around.

They tried breeding mosquitoes to cull the humans. But they outbred the losses. From the rainforests they unleashed biological controls like Machupo, Ebola and Dengue haemorrhagic fever. Their next ploy, the bushfire, was more dramatic. They accumulated tinder on the forest floor, then waited for the silly humans to plonk their new suburbs right next to it. Year after year, they scorched hundreds of Californians, Australians and Midi Frenchmen from their House & Garden homes.

But it was a losing struggle. The human race just seemed to keep on sprouting like, well, weeds. There was no controlling them - by poison, fire, insects, pathogens or even bureaucratically delineated management. The weeds became depressed, and for a while there was a kind of global botanical sulk.

Then, one day, a little weed growing in a footpath outside a concrete bunker somewhere near Houston, Texas, overheard something VERY IMPORTANT. Quickly she root-emailed it to the next-door weed, who copied it to six others and so on, until the message had reverberated on the rooty Internet all round the Earth. The message said, "George Bush, namesake of the weeds, has announced there is a ship leaving for Mars in 10 years".

"Does anybody know an astronaut who likes bushwalking?"

Aesop taught us that every good story has a moral, and here it's pretty plain: If you don't understand the effing problem, then stand it on its head. If we can't control weeds, then perhaps we should try controlling humans. Not literally, of course. Too Malthusian. But controlling them in the elevated sense of influencing them towards a more rational course of behaviour. This technique is known as science communication.
 
Humans are the vectors of weeds. It is our failure of stewardship, our failure even to see what is going on before our very eyes that is the cause of this problem. For example, of the 6,600 plant species, which are presently permitted to be imported into Australia, over 4,000 are known agricultural or environmental weeds. They include beauties like bridal creeper, Parkinsonia, and - wait for it - no fewer than 69 strains of blackberry! All perfectly legit.

Roughly one-in-ten of all the plants introduced into Australia eventually turn out to be a serious weed. Collectively, they now smother about 20 million hectares - which is 25 per cent more than the total predicted area of dry land salinity. Today it takes the entire export earnings of the gold industry just to pay for the damage weeds inflict on the economy. And this is only the start.

In 200 years Australia will have ceased to exist. There will still be a large rock with a recognisably Australian outline, but it will be submerged beneath a green tide of alien botanical life forms that will, in the course of their conquest, have eliminated every hairy-nosed wombat, koala, corroboree frog, wollemi pine, Richmond birdwing and bellbird on the planet. Australians will be a race of transplants in a transplanted land. Unless we learn to see now what is taking place right now in the bush landscape our grandchildren will never behold.

The average Aussie does not think weeds are a problem.

The very word implies something feeble and inconsiderable - a nuisance - not the Agent Orange of ecosystem obliteration, which some of them become. Yet they are our gravest environmental threat, and we invest only a fraction of the effort in controlling them, compared with tackling salinity, a less widespread problem.

As a science communicator I can only say that if we hope to control the "Green Death" - the wholesale landscape destruction which weeds cause - we must first muster the Australian people to the cause. Currently weeds are rated about 20th in a list of our environmental problems, which is another way of saying: They’re not on the public or political radar. Raising awareness will require long and repetitive discussion of the threat, its nature, its extent and its consequences. And its ultimate costs - financial, social and environmental.

It will involve engaging the public’s interest and enthusiasm. It will require their willing partnership, their sense of ownership of the issue. It took an Ian Kiernan to call the children of Australia to compel the adults to "Clean Up Australia". Who is the Kiernan of Weeds? Who is to lead the children of Australia on a campaign to root out and destroy every pestiferous patch that threatens our sacred landscape?

When will the politicians in their first-class airline seats and comfy air-conditioned limousines, who seldom in a lifetime set Gucci-shod foot in the real Bush, realise that they are presiding over the irreversible ruin of our land? Who is to tell them?

I hereby anoint every reader an Evangelist of Weeds. Whatever else you may do in your profession, you are now a Chosen One, and you must win one convert a day for the rest of your lives. On your deathbed, convert the padre who comes to give you final unction.

On a more serious note, arousing the Australian people and their governments to the imminence and magnitude of this threat is our most pressing task. Only when we have succeeded will there be the resources to do the science that checks the weeds. I end by declaring, not so much a War on Terror, as a War on Weeds.