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Sydney Red Gum
also known as Angophora Costata.
Photo taken at Blue Mountains
by Heidi Lee Warta

Gum Trees: Australia's Forest Trees

To the modern man, Gum Trees are the origins of an industry. To Koala bears, these trees are their home and food source. To the Aboriginal tribes, Gum Trees are sacred and symbols of purity, that which connects them and the land to the heavens. Some Gum trees grow so tall as if stretching to touch the sky. Some have lived so long, enough to tell the tales of the land long before its history was written. 

 

Named after the gummy and sticky substance that oozes out from a cut in its bark, Australian Gum Trees are otherwise known as Eucalyptus Trees. They produce a sap called ‘Kino’ - an organic resin that’s usually red in color. This sap production is a response to a boring insect - a eucalyptus borer, often a long-horned beetle. The insect would bore a hole into the tree’s truck or branches to make itself a nest. The Gum tree would then release its sap to wash out and kill the offending insects. Standing tall in dry land, Gum trees seem as if a bleeding miracle in its attempt to save itself from infestation. Sadly, such an infestation is also an indication of a stressed tree. They’re essentially quite thirsty. A weeping tree is already in trouble. However, as nature would have it, many species of Gum trees survive a drought and even bushfires. After a fire consumes the bush, new sprouts can emerge out of the ashes. Some species survive in cooler environments. 812 species of Eucalypts are native to modern Australia. Some are endemic only to the continent. The remaining of a total of 826 Eucalyptus species naturally occur in The Philippines, Indonesia and the Pacific Islands. Due to human movement, many Eucalyptus species are currently grown all over the world due to economical or aesthetic interest. In a deeper investigation of its origins, scientists have yet to find fossil evidence of Eucalypts in Australia. However, climate and conditions of the land may contribute to the lack of fossilized Eucalyptus. 

Eucalyptus and the Australian Landscape
Not all Eucalypts are Gum Trees but all Gum Trees are Eucalypts. In Australia, most forests are populated by Gum Trees. The most famous of Gum trees are widely known throughout Australia due to their distinct characteristics. Each of the Australian Regions have different climates which of course, affects the variety and characteristics of its wildlife. Eucalyptus forests also vary. The eastern region with its cooler climate and mountains is home to the largest variety of Eucalyptus species and wildlife. The southern region, also with a cooler climate, grows endemic species. The northern region, which is tropical and subtropical, has forest growth that is far less dense and Eucalyptus species that are more adapted to warm and dry environments. The western region belongs to the Jarri, Marri and Karri forests. Among the tallest trees of the world, these are the tallest Eucalyptus species that reach 60-90 meters high. The Karri or Eucalyptus Diversicolor is a flowering hardwood that grows straight with a smooth deciduous bark that when shed reveals a multicolor pattern. It propagates from seed only unlike other Eucalypts that can regrow from its own trunk base or branch with dormant buds. Jarri/Jarrah or Eucalyptus marginata  are endemic to Western Australia. It can grow up to 50 meters with a trunk diameter of up to 2 meters, fibrous reddish brown bark, white to yellow flowers, and long dark green leaves that’s glossy. Its glossy canopy of leaves tends to reflect sunlight, making it quite vibrant in a beautiful sunny day.The Marri or Corymbia calophylla grow up to 40 meters tall having rough tessellated brown bark usually with streaks of Kino or gum. It’s name Marri means ‘blood’ in Nyoongar (Aboriginal). 
 
These forests are the habitat of around 20% of Australian animals. The most famous of which is the Koala bear, live in trees along with Yellow-bellied Gliders, Cockatoos, Lyrebird, the Australian Owlet-nightjar, the Yellow Robin insects such as the Blue-banded bee, Orb-weaving Spiders, Eucalyptus Weevils, and even ants. Many amphibians live in Eucalyptus forests such as the Spotted Python, Frilled Lizard, Tiger Snake and the tree hugger, Carpet Python.
Eucalyptus: Purpose and Value

Eucalyptus trees are rich in oil - the distinct fresh fragrance infused in many products all over the world. The oil is found in glands in their leaves. Of course, these make the trees prone to fire. As fires start in the bush, it spreads and escalates as it consumes the residing Eucalypt species. While these bushfires pose a danger to both humans and wildlife, it is a natural occurrence that can be a controlling factor in the ecosystem. Meanwhile, since the arrival of the west to Australia, Eucalyptus trees have proven its value to industry. These trees have been a source of oil, wood and paper. Further, studies prove medicinal properties of Eucalyptus oil. The scent alone can ward off insects and have been a staple in various products such as bath soap and candles. In parts of Europe, California and Sicily, Eucalyptus are known to be cultivated for the purpose of draining water off land. As these trees can soak a large amount of water, they are planted in an effort to eliminate or diminish the presence of swamps and, in turn, mosquitoes and other issues brought on by non-flowing water. This cultivation, however, is a man-made issue that has also brought on problems to the new ecosystem. Their fast-growing nature makes them invasive to the land, successfully competing against naturally occurring foliage. 

Keeping Us Connected

Gum Trees have continued to thrive in both rural and urban areas in all of Australia. Though urbanization is a key factor to diminishing forests, support for the cultivation of Gum trees have long been present but true conservation started only in recent years. Currently, old growth forests are quite smaller than hoped for due to timber harvesting and bush fires. With growing efforts, Australian Gum Trees may have a better future through better conservation and cultural preservation. As part of these mechanisms to protect precious Gum Trees, Australian groups have put in efforts to strengthen appreciation and connection of the people to the land in sectors of science and the arts. Written and visual story-telling through the arts such as the works of Heidi Lee Warta, has the power to create a lasting impact. It is the culture and connection of the land and its people that will improve conservation and preservation of Gum Trees.

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