It is not often that a tree is cast as the villain of the piece. But a report from Florida - now known as much for Orlando and Mickey Mouse as for anything else - has the Australian melaleuca tree convicted as an evil blow-in. What does it do? It proliferates at an incredible rate and is sucking the water out of the Everglades National Park, which is just 50 years old. It is an astonishing place, writes a friend who recently visited there, home to much wildlife which is dependent on water: egrets, ibis, blue heron, turtles. Yet there are now only a tenth of the wading birds counted at the beginning of the century.
The reason: unreasoned introduction of that one specimen of tree, specifically brought in to drain the Everglades of excess water. If there ever was an example of the dangers of importing a solution without long and careful trial, it is this. For, fine as it may have been in Australia, the melaleuca has brought the Everglades to a state of near-disaster. It did drain them and now they can't stop it, and the water is becoming dangerously low.
The melaleuca never had it so good. It produces seed in huge quantities. It is more or less immune to fire. It is a pest now, forming an almost impenetrable mono-culture over hundreds of thousands of acres, threatening what is regarded as an internationally-known eco-treasure. One way is to pull out the trees, which can grow alarmingly high. At present biologists are experimenting with a beetle which goes for only one plant - the same melaleucas. The intention is that the beetles eat the buds of the tree before they can drop their seed. John Grogan, a local columnist, hopes the experts know what they are doing. For he writes that in the 1930s sugar growers imported poisonous toads to fight a cane weevil. With no natural enemies, the toads proliferated, eating just everything but the beetle. And he wants to know: when the last melaleuca is gone, will all those hungry beetles just lie down and die, or will they answer the evolutionary call to adapt to new food sources - say, Florida citrus?
The kind friend who brought all this news back from a recent trip, says that all sorts of unlikely proposals have been put forward. Including, strangely, carp from Arkansas which, presumably, will eat at the roots. A touch of Mickey Mouse there?