Here’s a trick question: how many animals do you depend on every day to stay alive? How many plants? And what about other living things?
You might eat bacon for breakfast so that’s pigs. You might have it with eggs on toast, so that’s chooks and wheat and yeast. You’ve got to digest it, which means all those micro-organisms in your gut. Of course pigs eat plants and other stuff, and so do chooks. The plants grow in soil, so that’s worms and funguses and nematodes and bacteria and insects and microcrustaceans and all the other soil critters.
You haven’t even finished breakfast yet, and you’re already in the thousands, maybe even the tens of thousands. Now take a breath: where do you think all that oxygen came from?
The answer to the trick question well, maybe it wasn’t that tricky is that you depend in one way or another on millions of fellow species every minute of every day just to stay alive. And they depend on you too. You’re tangled in the Earth’s food web as surely as if you were a yabby or an apple tree.
It’s an easy thing to forget. Humans live a world of plastic and concrete; we don’t think of ourselves as being part of all that messy eat-and-be-eaten stuff but even your own backyard is a miniature jungle.
Four years ago a researcher at Macquarie University, Andrew Beattie, tried to count how many species lived in an average Sydney backyard all the animals, birds, plants, insects, worms, spiders, micro-organisms and so on.
Professor Beattie counted at least 4,620 different species living in just one suburban backyard. Almost certainly, he says, there were many thousands more species which he missed.
So here’s another question. How many of those millions of species which we depend on every day could we actually do without? Surely we don’t need them all.
Well. Maybe we could get by without one or two species of beetle. And if all the pigs were gone we could eat mutton. Probably we could manage without bread. Or at least we could get by on just one variety of wheat surely we don’t need all those endless different strains?
That is precisely what humans are now doing to the world. We are rapidly weeding out animals and plants we don’t want and sending them to extinction. We are whittling away at the diversity of life probably faster than has ever happened before.
Some estimates say 10,000 species are vanishing each year. The truth is no-one really knows.
Imagine you are about to board an aeroplane. As you climb on you see a work crew pulling out rivets from the wings. No problem, they explain, the ‘plane doesn’t depend on any single rivet for its strength.
How many rivets would you let them take out before you refused to board the ‘plane? That’s what biodiversity (or biological diversity) is all about conserving the variety of life on Earth for future generations.
Who knows what species might come in handy one day? Who knows, for example, what strain of wild grass might one day be crossed with wheat to make it resistant to a new pest maybe a pest which doesn’t even exist yet? Who knows what life-saving drugs might one day be extracted from Australia’s native plants and animals? Biodiversity is the Earth’s insurance policy.
Thousands of organisms which at first appear to have nothing to do with humans grubs in the ground, floating plankton way out at sea, trees growing in distant forests all actually help clean and recycle the air, water and soil that we depend on for our survival.
Never before has biodiversity been so much under threat. All over the planet, including in Australia, humans are changing the environment to make way for houses, farms, roads and other developments. The species which lived there before usually don’t survive.
You can’t conserve biodiversity in a zoo all you could hope to save would be a few big animals. Conserving biodiversity has to be 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.
Author: David Mussared
Source: Department of the Environment and Water Resources . June 20, 2004.