The Uses of Eucalyptus Plants

The Eucalyptus genus comprises 700 species of native Australian trees, including the most often planted hardwood timber trees worldwide. The leaves and roots yield an antiseptic aromatic oil used in cosmetics and over-the-counter medicines. By 2000, 20 million hectares (50 million acres) of eucalyptus were planted outside Australia. The fastest growing market is Brazil, where breeding programs first bred site-specific clones. In 2010, the U.S. Department of Agriculture authorized planting of test plots for eucalyptus timber genetically engineered to tolerate frost.

Medicinal Use

Hundreds of Eucalyptus species contain volatile oils, but only about 20 have commercial potential. The medicinal aromatic oil in eucalyptus is variously called 1,8 cineole, eucalyptol or cajeputol. Cineole is soluble in oil, water and alcohol and is widely used in over-the-counter cold and asthma remedies. Since 1852, Eucalyptus globulus has been the main species for cineole production, most of which takes place outside of Australia. In 2007, the leading producer was China, followed by Portugal, Spain, India, Brazil and Chile.

Scent

Two eucalyptus species are commercially used for perfume scents. Eucalyptus citridora yields volatile citronellal oil that is fractionated before use as a scent for soap, perfumes and disinfectants. Natural citridora oils reach the market in direct competition with industrial substitutes synthesized from turpentine. The leading producer is China, followed by Brazil and India. Eucalyptus staigeriana yields a lemony scent due to its high limonene content among other turpenes. Brazil is the major producer of staigeriana scents, which are used in perfumes without further chemical processing.

Pulp

Portugal developed Eucalyptus paper pulp in 1906. At 2 million tons of bleached pulp annually, Brazil is the largest producer outside of Australia. In 1997, Australia exported 2.5 million metric tons of bone dry eucalyptus pulp, accounting for 1% of Australia's gross domestic product. Eucalyptus provides half of Australia's domestic pulp use of 10.3 million cubic meters annually, with pine plantations providing the remainder. Eucalyptus pulp businesses employ 40,000 Australian workers. In 1930, Australia's natural timber supply exceeded demand, but forests were logged, cleared for agriculture or burned. Native forests of 124 million hectares were reduced to 28 million, with 15 million inaccessible or conserved.

Wood

Eucalyptus globulus is widely cultivated for wood products, including plywood, particleboard, fiberboard, poles and posts, veneers, flooring, crates and pallets, furniture and building construction materials. Eucalyptus has high moisture content and must be air dried to 30% moisture and then kiln dried and steam reconditioned to 12% moisture before market. Eucalyptus wood is hard and can blunt saws, but it easily bends, stains and glues.

GMO in the USA

In North America, eucalyptus is rarely cultivated north of Florida or the central valley of Arizona. In 2010, the USDA authorized ArborGen, a South Carolina-based biotech, to plant 200,000 clones of genetically modified eucalyptus on seven experimental plots of 20 acres or less. Genetic modification eliminates pollen production in these clones. ArborGen, a subsidiary of three global timber producers, claims rapid growth minimizes commercial plantation size. Environmentalists object to the alteration of eastern woodland habitat.

Keywords: Eucalyptus globulus, ArborGen, cineole, cajeputol, eucalyptol

About this Author

Sara Kirchheimer holds a Bachelor of Science in physical geography from Arizona State University and is currently retired from the transportation and travel industry in northern Europe and the western United States. In addition to commercial writing, she has contributed art exhibit reviews to Phoenix Arts and hurricane update articles to New Orleans Indymedia.