by DAL STIVENS
DAL STIVENS is an Australian novelist and short story writer, and also a keen amateur naturalist. This article is reprinted from American Forests. Photographs are from the Australian News and Information Bureau.
Note: 1 acre = 0.4 hectare; 1 mile = 1.6 kilometers; I square mile = 2.6 square kilometers; I inch = 2.5 centimeters; I foot = 30 centimeters; l pound = 0.45 kilogram; I cubic foot = 0.03 cubic meter.
No other tree has been so widely propagated
AUSTRALIA's most dramatic export "was how the then Australian Minister for External Affairs, Mr. R. G. Casey (now Lord Casey) described the eucalypt when welcoming forestry experts from 24 countries to Australia in 1952. The forestry experts had come on a two months' Eucalyptus Study Tour organized by the Food and Agriculture Organization of the United Nations.
Mr. Casey's phrase was well chosen, for no single tree has ever been so widely propagated throughout the globe as the pungent smelling, evergreen eucalypt. Besides its Australian homeland, eucalypts grow in most of the temperate regions of the world - in 50 countries which include Argentina, Brazil, Britain, Cameroun, Ceylon, Chile, Congo, Cuba, Cyprus, France, Greece, India, Indonesia, Iraq, Israel, Italy, Jordan, Kenya, Libya, Madagascar, Malaya, New Zealand, countries of north Africa, Nigeria, the Pacific Islands, Paraguay, Portugal, Puerto Rico, Rhodesia, South Africa, the U.S.S.R., Spain, Tanganyika, Turkey, the United States (Arizona, California, Florida, and New Mexico), and Uruguay.
Brazil is the leading overseas cultivator of eucalypts. She has 2,000,000,000 trees on 1,500,000 acres (according to a recent official estimate), and has been cultivating them for over 70 years - ever since an enlightened mine manager became disturbed at the destruction of Brazil's natural forests. Over 100 species of eucalypts are grown in Brazil.
South Africa is estimated to be the second eucalypt nation with some 450,000 acres. As visiting Australians have noted, much of the areas surrounding Cape Town and Durban have a distinctly Australian look. Nine out of every ten tall trees you see are eucalypts.
Madagascar is next with 340,000 acres, followed by Spain with 250,000 acres, and Portugal with 160,000 acres. California has 2,000 miles of eucalypt windbreaks protecting citrus orchards. Israel is also a leading eucalypt planter; she has lined 650 miles of roads in recent years, and has been growing eucalypts for about 70 years.
Currently, there's a eucalypt boom overseas. The Forestry Bureau at Canberra has set up a special eucalypt seed bank to meet the thousands of overseas requests which reach it each year. The Food and Agriculture Organization of the United Nations has published in several languages a 400-page book, Eucalypts for planting On a lighter note, a Californian wrote to Western Australia for seeds of the jarrah (Eucalyptus marginata) and a local newspaper headlined it: HE WANTS TO GROW FIREBRICKS! Western Australians (and some others) understood the joke. This eucalypt is wellnigh fireproof and in the big timber country they use it for chimneys. After years of roaring log fires the jarrah planks are barely charred.
The current boom in eucalypt planting abroad is likely to continue unabated in a world that is belatedly aware of how prodigal it has been with its forests in the past.
What is the explanation of the eucalypt's extraordinary ubiquity? It is not the best tree in the world - if such a thing exists - but it is possibly the best all-round general purpose tree.
First, it is adaptable. It will grow in any region where the winters are not too severe; some migrants have survived zero Fahrenheit. And there are eucalypts for almost every condition. Over 600 species of eucalypts have been classified in Australia where they spread over a huge continent of 2,974,000 square miles - almost as big as the United States - with a wide range of rainfall and temperature variations. Some thrive in the hot dry center where the rainfall is under 10 inches a year - and none in a particular year. Others flourish among the coastal sand drifts, above the snowline in the Australian Alps, and in the wet tropical areas of northern Queensland.
The eucalypts range from 300-foot giants to dwarf trees (called mallees) whose lumpy roots store sap to tide them through years of drought. One eucalypt, the blue gum (E. globulus) which does so well in California, grows equally happily at 8,000 feet in the Himalayas and 10,000 feet on the equator in Peru.
FIGURE 3. - The yellow box eucalypt (Eucalyptus mellidora) has a fragrance which attracts bees as do many eucalypts.
The genus eucalyptus is, indeed, a most protean one - and, in passing, something of a botanical nightmare. Identification of the species of this diverse genus is very difficult even for expert botanists. The hark and general appearance of a tree are not sufficient for purposes of classification - young and old leaves, buds and fruit have also to be considered. The dividing line between species and variety often remains uncertain and often a matter of individual opinion.
The name eucalyptus, incidentally, was first given to the genus in 1788; this Greek-derived compound of eu= well and kaluptos = covered was the French botanist l'Heretier's description of the lid (operculum) which covers the stamens of the tree's flowers in the bud stage.
Eucalypts suggest only gum trees to most people, including many Australians. But in fact, there are many eucalypts which are not gum trees. The smooth-trunked handsome gum trees with twisted clutching arms which exude kino (an astringent gum) number only 120 species. They periodically shed their bark in ribbons and plates - you could call the gum tree "the evergreen with deciduous bark." Popular names are confusing - blue gum is applied to at least eight different species, red gum to 10, and white gum to 15 and names such as ash and mahogany are popularly given to some eucalypts.
The other eucalypts can be broken up very broadly into two classes: those with rough permanent barks which are called stringybarks, boxes, and ironbarks: and those which want the best of both eucalypt worlds, the blackbutts and woollybutts, which have smooth upper branches and rough bark trunks.
Another merit of the eucalypt which wins it friends abroad is its quick rate of growth. It is claimed that it grows much faster than any European or North American hardwood tree. Growths for some species of 35 feet from seed in 16 months and 25 feet in the first year have been recorded: a height of 60 to 70 feet in the first 20 years has often been observed. (There's even some evidence that when cherished abroad some eucalypts grow faster than they do in their Australian homeland. Leastways, that's what some Californians claim, but they have been known to make extravagant claims before for their wonderful climate! However, they grow blue gums in Spain chiefly as a source of rayon and harvest them when they're nine years old - and 60 feet high!)
Speedy growing eucalypts are the chief source of fuel in some Asian countries which have little or no coal.
A third and pre-eminent virtue of the eucalypts is their fine timber. Australian hardwoods were exported long before the young continent shipped wool, wheat, butter, fruit, or metals. Builders in Great Britain soon learned the toughness, strength, weight, and hand-someness of Australian eucalypt hardwoods. In the actual degree of hardness there is considerable variation. Some of the boxes and ironbarks rank among the hardest in the world; others such as the miscalled mountain ash are reasonably easy to work.
Taking Australian eucalypt woods as a whole, you can divide them into two classes - the colored or red woods and the pale woods. Most of them have a density (relative to weight of water in a cubic foot: 62.4 pounds) of 40 to 75 pounds a cubic foot. Two of them - karri (E. diversicolor) and tuart (E. gomphocephala) - are so strong that they have been used to replace steel in rail tracks. Many are exceedingly beautiful in grain and color. Some of the best are the grey ironbark (E. paniculata), red mahogany (E. resinifera), jarrah (E. marginata), the blue gum (E. globulus), mountain ash (E. regnans), river red gum (E. rostrata), spotted gum (E. maculata), and mountain grey gum (E. goniocalyx).
King of the Australian eucalypts is the giant mountain ash (E. regnans), one of the world's biggest trees, and probably only overtopped by the sequoias of North America. The mountain ash grows up to 300 feet in the mountains of Victoria and Tasmania. The tallest E. regnans is in Tasmania and tops 326 feet. Mountain ash timber is pale-colored with a wonderful straight grain. It has many commercial uses.
Western Australia, too, has its forest giants - the karris which soar up to 250 feet and more. Karri is a deep red-colored timber, hard, heavy, and tough with an interlocked grain. The jarrah (E. marginata), is one of the most durable of the eucalypts. Its rich, medium hard timber resists fire, water, and boxing insects. Used as wharf piles it has resisted teredo for 50 years; fencing posts and railway sleepers of jarrah have lasted up to 50 years; jarrah beams have been merely charred in fires which have buckled stout steel girders. Another durable timber is wandoo (E. redunca), also from western Australia.
Some of these eucalypt timbers have won a worldwide reputation. Jarrah sleepers have been used in South Africa, Ceylon, Mauritius, Malaya, and various Middle East countries. Tasmanian blue gum piles and New South Wales turpentine piles are used in wharves in many of the world's ports. Jarrah and karri for wagon scantlings, mine guides, etc. have been imported into the United Kingdom and Europe - much of London's traffic used to roll over jarrah blocks. New South Wales spotted gum and other hardwoods are used for railways sleepers in South Africa: New South Wales ironbark is employed in the construction of boats plying in sub-Arctic waters. The so-called Tasmanian oak (still a eucalypt) has established a very high reputation particularly for flooring, in the United Kingdom and elsewhere. Exports to the U.S.A. are small, totaling 72,000 board feet of constructional grades in a recent half yearly period.
Besides providing strong durable timbers, eucalypts are a source of paper pulp, essential oils used in pharmacy and industry, and of nectar for honey bees. (About half of Australia's newsprint is provided by eucalypt hardwoods.) Many of the eucalypts are a rich source of tannin and of myrton, used in tanning.
FIGURE 4. - A snow gum eucalypt of the Great Dividing Range (Australian Alps) near Cabramurra, New South Wales.
FIGURE 5. - The red gum eucalypt is one the most durable of the 260 different species of the Eucalyptus family.
One Western Australian eucalypt, brown mallet (E. astringens), is particularly bountiful in myrton, yielding 40 to 45 tons to the acre.
Throughout the world today eucalypts are cultivated for a wide range of needs. Brazil grows them for railroad ties, paper pulp and fuel. In Spain and Portugal they provide mine timbers, paper pulp, and viscose cellulose. In Asia, central and South Africa they meet the needs for fuel. Italy, Morocco, and Israel grow eucalypts for fuel, paper pulp, soil stabilization, and crop protection. Thailand and India cultivate eucalypts for fence posts and round timbers.
Eucalypts are harvested in some countries including Australia for their essential, industrial, and medicinal oils. One oil, cineol, is used in pharmacy, confectionery, and dry cleaning. Another, eudesmol, is used as a fixative in perfumes. A third is a synthetic terhineol (hyacinth scent), citronella, and synthetic menthol. Another eucalypt extract, phellandrene, is used in the flotation of metals. About U. S. $ 200,000 worth of rutin, a crystalline substance extracted from some species of eucalypts, is exported from Australia to the U.S.A. each year. Rutin is of therapeutic value.
Countries which cultivate eucalypts also look for a bonus in increased honey yields. The piquant-smelling fluffy blossoms are a rich source of nectar. Eucalypts explode in showers of cream, pale yellow, chartreuse, pink, or scarlet blossoms and constitute a gigantic pasture for Australian bee-farmers. Australian apiarists gather 300-400 pounds of honey from each hive.