eucalyptus leaves

[sabrinah]

why do these trees have flammable leaves?

[rekstout]

It might be an evolutionary trait which thins out trees by natural fire (caused by lightning strikes) allowing the survivors less competition (and also replacing vital soil nutrients through the ash) Alternatively, I know some plants seed pods will only pop open and distribute seed when they are exposed to extreme heat.

[incitatus]

Yes. Its quite deliberate. The oils in the leaves, as well as making them unpalatable to anything except Koalas, render the leaves flammable. Many species of eucalypt have a thick, corky or fibrous bark which acts as a fire blanket, so they set fire ot everything around them, often survive it, and if not there is an open playing field for their offspring. In fact the whole Australian eucalypt forest ecosystem is designed around periodic fires. The reason there has been so much trouble recently is (climate change excepting) that man has stopped the periodic burn-offs. This means that instead of a patchwork of young trees and old trees, which would break up the fire, you have all old flammable trees. I understand the parks service is now dealing with this...