Biology Articles » Biodiversity » Don't Read This, You Know It All Already - Why Farmers Should Care About Biodiversity

Don't Read This, You Know It All Already - Why Farmers Should Care About Biodiversity

Don't Read This, You Know It All Already - Why Farmers Should Care About Biodiversity

If you're a farmer maybe you shouldn't bother reading on. You already know most of what I'm going to say. Except maybe the word I'm using won't mean much to you - "biodiversity".

Ugly word, biodiversity. Sounds like it was invented by a computer.

Actually it's worse than that; it was invented by scientists. Scientists and conservationists around the world have finally woken up to what farmers have known all along: variety matters.

The other thing scientists and conservationists have finally woken up to is that variety, in the wild, is rapidly disappearing. What happens when the regions which used to grow the wild ancestors of wheat have all been turned into townhouses and freeways? What happens next time there's a new pest or disease and the plant breeders look for some resistant wild grass to cross-breed with modern wheat?

Biodiversity just means variety, pure and simple: the variety of life. Everywhere, including Australia, it is under threat. The Irish potato famine is a good example of what can happen when a nation becomes too dependent on one variety. In agriculture, in the long run, diversity is strength.

Seed banks, where technicians store many different varieties and grow them every now and then to make more seed, are one answer. They've sprung up all around the world - there's one run by the CSIRO in Canberra which stores thousands of different varieties of eucalypts, wattles, casuarinas and other Australian trees.

But seed banks for plants and zoos for animals are never going to be able to conserve everything. There are something like 475,000 native species in Australia, not counting micro-organisms. Most of them live only in Australia, and any one of them might contain the cure for AIDS or cancer, or they might contain the gene to fend off some new agricultural disease.

Take soybean for example. There are at least 16 Australian native plants which are distant relatives of soybean, one of the world's most important crops. The Australian soybean relatives - called Glycines - grow in poor, salty soils and are naturally resistant to soybean diseases.

Not surprisingly scientists from the United States and Australia have been trying hard, with some success, to cross various Glycines with commercial soybean varieties.

Another example is cotton. The Northern Territory's floral emblem, the desert rose, is a wild relative of cotton. The CSIRO is trying to collect desert rose seeds from all over Australia. The scientists think they might be able to breed an Australian cotton which grows further south, or which produces cottonseed not laced with the toxin gossypol.

Aside from wild relatives, there are plenty of Australian native species with potential to become major world crops or farm animals. Australian wattle-seed, for example, is already being tested as a food crop in famine-struck sub-Sahara Africa. Macadamia nuts have been grown for many years around the world, as have eucalyptus, wattle and casuarina trees. Silver perch from the Murray-Darling Basin are grown in fish farms throughout South East Asia. yabbies, marron, crocodiles, emus and kangaroos are all finding markets. The Australian native flower industry has tremendous prospects; bush tucker is finding its way on the menus of some city restaurants.

Wild species also form the backbone of much of the world pharmaceutical industry. Six of the world's 20 top-selling drugs came either directly or indirectly from nature. Of the 43 new chemicals introduced to the world pharmaceutical market in 1993, 18 came from natural sources. The size of the world pharmaceutical market is now so huge that just one new drug discovery in Australia could rival our wheat or wool exports.

The Swedish company Astra Pharmaceuticals - Scandinavia's largest pharmaceutical group - last year signed an agreement in Queensland to spend $10 million over the next five years screening chemicals found naturally in that State's rainforest and Great Barrier Reef. An Australian company, Amrad, has announced plans for screening in the Northern Territory.

Biodiversity is important for other reasons too. Plants, animals and other organisms make the air we breathe, clean the water we drink and continuously recycle the soil all like depends on. They provide essential "services" to humans and all other living things, without which we could not live.

In Australia research has found that the biggest threat to biodiversity is the clearing of native scrub for farms and suburbs. The second biggest threat is introduced plants and animals.

The most cleared areas of Australia - aside from cities - are its farmlands, especially the wheat and sheep belts of eastern and western Australia. Up to 95 per cent of the wheat belt has now been cleared of its original native vegetation, much of it since World War II.

Threats to biodiversity on Australian farms are not all in the past. Clearing is still happening. A study of satellite images published earlier this year found that surviving bush fragments in the New South Wales wheat were still shrinking fast - in one large area 70 per cent of the remaining native vegetation vanished between 1977 and 1985. Remnant native bush on private land is an important refuge for Australian biodiversity; clearing such patches might not be in the long-term interests of farmers.

Evolution of a new species or a new variety can take tens of thousands, even millions of years, extinction can happen in a decade. For each big animal we know has disappeared there might be dozens of species we never noticed - inconspicuous plants, insects, funguses - which have vanished as well.

You can't conserve biodiversity in a zoo. All you can hope to save in zoos are a few of the big, cute animals. Conserving biodiversity is everyone's responsibility. The CSIRO is now mounting a major research effort to learn more about Australia's unique biological heritage, and how best to preserve it.

Last year, all around the world, the global Convention on Biological Diversity came into force. It is an international agreement, negotiated under the umbrella of the United Nations, to conserve biodiversity. Australia has joined it, so have more than 50 other countries. In line with the Convention, Australia's Federal, State and Territory Governments are expected to launch a joint national strategy to conserve Australia's biodiversity later this year.