There are ecological threats and, if you compile news bulletins for the ABC, there are threats of an entirely different variety. Take CO2, for example, which AM on Friday mentioned as placing red gums in dire peril, albeit at some undisclosed distance of years to come. Listen to the item here and learn how, were you to cultivate those trees in greenhouses gassed-up with 800ppm carbon dioxide — twice current atmospheric levels — they won’t do so well, being prey to leaf-eating bugs and hungry koalas. The item concluded, as you might expect, with the plea that much more research is needed. Keep those grants coming!
The curious thing about the ABC’s decision to showcase this particular prophecy of red gum doom is that a prime and undisputed cause of the trees’ woes has been known for quite some time. Alas, the cause and solution aren’t palatable to those who prefer to fret about a trace gas in unworldly concentration, rather than the real damage done by greenish policies that prevent prophylactic burning, thereby promoting both the worst kind of bushfires and insect populations that would otherwise have been suppressed by the drip torch and controlled flames.
More than that, the recognition that man’s thumb exerts a considerable weight on the current ecological scale is anathema to those who promote the myth of “wilderness”, that manifestation of green romanticism which insists large tracts of the bush remain as they were before humans set foot on the continent. Lock up the bush, the eco-zealots insist, and Nature will make everything pristine once more. Given at least 50,000 years of active Aboriginal stewardship and the subsequent impact of white settlement, radically altered land use and feral species, nothing could be further from the truth. The only beneficiaries of sealing national parks and state land are rabbits, foxes, cats, dogs, pigs, deer, horses, not to mention cape broom, chinese honeysuckle and a veritable United Nations of invasive weeds.
Bushman and naturalist Alfred Howitt, the man whose considerable achievements included retrieving the bodies of Burke and Wills, knew as much in the 1860s, when he began to suspect that the end of Aboriginal “fire-stick management” had led to plagues of caterpillars. Howitt wrote:
These instances show how the occupation of Gippsland by the white man has absolutely caused an increased growth of the Eucalyptus forests in places. I venture, indeed to say with a feeling of certainty, produced by long observation, that taking Gippsland as a whole, from the Great Dividing Range to the sea, and from the boundary of Westernport to that of the New South Wales, that in spite of the clearings which have been made by selectors and others, and in spite of the destruction of the Eucalypts by other means (to which I am about to refer), the forests are now more widely extended and more dense than they were when Angus McMillan first descended from the Omeo plateau into the low country.
I have spoken just now of the destruction of the Eucalypts by other means than the hand of man, for clearing his holdings, and the following are the facts I have gathered concerning the subject:
About the year 1863-64 I observed a belt of Red Gums which extended across the plains between Sale, Maffra and Stratford were beginning to die. Gradually all the trees of this forest, as well as in other localities, perished. At that time my attention was not drawn to the investigation of the cause. Later, however probably about 1878, I observed the Red-Gum forests of the Mitchell River Valley to be dying, just as those at Nuntin and elsewhere had died years before.
I then investigated the subject, and found the trees were infested with myriads of the larvae of some one of the nocturnal Lepidoptera. These devoured the upper and under epidermis of the leaves, thus asphyxiating the tree.
Some 75 percent of the forest died that year, and subsequently almost all the surviving trees died also. Since then I have observed the same larvae at work, some of which, when kept until they had passed through their several metamorphoses to the perfect insect, were pronounced by Professor McCoy to be examples of Urubra lugens (pictured above). Whether this insect has in all cases been the agent in destroying the Red Gums I cannot affirm. Probably not wholly, but I am satisfied that the greater part of the Red Gum trees which have died in Gippsland from obscure causes have been killed by its agency.
The inference may be drawn from the above observations of forests having been killed by infesting insects, that each species, will have attached to it some particular insect which preys upon it rather than upon any other Eucalypt…
…I have said that in my opinion the increased growth of the Eucalyptus forests since the first settlement of Gippsland has been largely due to the checking of the bush fires year by year, and to the increase thereby of the chance survival of the seedling Eucalypts, and to the same cause we may assign the increase of the leaf-eating insects which seem in places to threaten the very existence of the Red Gum.
Howitt wrote those words in the last decades of the nineteenth century. Yet here we are, getting on for 140 years later, and an observant bushman’s analysis and warning remains largely unheeded. If only he had blamed global warming, his paper might today not be so nearly forgotten.
Roger Franklin is the editor of Quadrant Online.