page_title: Eucalyptus
section_title: Fire hazard
hierarchical_section_title: Eucalyptus / Adaptation to fire / Fire hazard
caption_attribution_description: English: Eucalyptus trees in the San Dieguito River Valley after the firestorm of 2007.
context_page_description: Eucalyptus is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with other genera in the tribe Eucalypteae, they are commonly known as gums or eucalypts. Plants in the genus Eucalyptus have bark that is either smooth, fibrous, hard or stringy, leaves with oil glands, and sepals and petals that are fused to form a "cap" or operculum over the stamens. The fruit is a woody capsule commonly referred to as a "gumnut".
  Most species of Eucalyptus are native to Australia, and every state and territory has representative species. About three-quarters of Australian forests are eucalypt forests. Wildfire is a feature of the Australian landscape and many eucalypt species are adapted to fire, and resprout after fire or have seeds which survive fire.
  A few species are native to islands north of Australia and a smaller number are only found outside the continent. Eucalypts have been grown in plantations in many other countries because they are fast growing and have valuable timber, or can be used for pulpwood, for honey production or essential oils.
context_section_description: Eucalyptus oil is highly flammable; ignited trees have been known to explode. Bushfires can travel easily through the oil-rich air of the tree crowns. Eucalypts obtain long-term fire survivability from their ability to regenerate from epicormic buds situated deep within their thick bark, or from lignotubers, or by producing serotinous fruits.
  In seasonally dry climates oaks are often fire-resistant, particularly in open grasslands, as a grass fire is insufficient to ignite the scattered trees. In contrast, a eucalyptus forest tends to promote fire because of the volatile and highly combustible oils produced by the leaves, as well as the production of large amounts of litter high in phenolics, preventing its breakdown by fungi and thus accumulating as large amounts of dry, combustible fuel. Consequently, dense eucalypt plantings may be subject to catastrophic firestorms. In fact, almost thirty years before the Oakland firestorm of 1991, a study of eucalyptus in the area warned that the litter beneath the trees builds up very rapidly and should be regularly monitored and removed. It has been estimated that 70% of the energy released through the combustion of vegetation in the Oakland fire was due to eucalyptus. In a National Park Service study, it was found that the fuel load (in tons per acre) of non-native eucalyptus woods is almost three times as great as native oak woodland.
caption: Eucalyptus trees bent over due to the high winds and heat of the October 2007 California wildfires. They are located in the San Dieguito River Park of San Diego County and leaning west
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