Why do eucalyptus trees have flammable leaves

A. There are around 700 species of eucalyptus tree, some of which have leaves that contain a highly flammable oil, although the trees themselves are relatively flame proof.

The flammable leaves have evolved to help spread small, natural fires.

Q. How does the eucalyptus tree escape injury during a forest fire

A. The bark burns away quickly by igniting easily and falling off. The core remains intact and afterwards a chemical reaction produces new shoots and the tree regenerates.

Q. So, fires are good for forests

A. In places that are naturally hot, like Australia, which has seen some very bad forest fires recently, natural, intermittent fires are part of the natural ecosystem, for forests at least.

Fire offers trees many long-term benefits. However, for many other creatures, like kola bears and kangaroos fires only mean death.

Q. How do fires benefit forest regeneration

A. Because they ensure that organic matter littering the forest floor decomposes quickly into minerals, which provide essential nutrients, like nitrogen, for the soil.

In fact periodic natural fires are so important for forest regeneration that some species of tree are dependent on them. The seeds of some trees can only germinate after they have been exposed to fire.

Of course fires started deliberately by humans have a devastating effect on forests and are no way comparable to the benefits of natural fires.

Q. Do eucalyptus trees have any other special features

A. Some species contain an essential oil with anti-catarrhal, anti-fungal, antibiotic, and antiseptic properties, which is used for fighting viruses that affect the respiratory system.

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by Lisa Cardy