What is a mountain ash tree?
The mountain ash is the tallest flowering plant in the world, a eucalyptus that can grow over 90 metres tall in the wet forests of Victoria and Tasmania.
Mountain ash, Eucalyptus regnans, has a straight, pale trunk with long ribbons of shedding bark near the base. It grows in cool, wet mountain forests such as the Central Highlands of Victoria, the Otways and southern Tasmania.
The tallest known living mountain ash, named Centurion, stands about 100 metres tall in Tasmania's Arve Valley. Historical records describe even taller trees cut down in the 1800s.
Fire-dependent giants
Unlike many eucalypts, mountain ash usually dies in intense bushfires. The fire releases seeds from the canopy, and a new even-aged forest springs up from the ash bed. Without fire, the trees cannot regenerate easily.
Old mountain ash forests store large amounts of carbon and provide hollows for animals such as Leadbeater's possum, Victoria's critically endangered faunal emblem.
Logging of these forests was controversial for decades. Victoria ended native forest logging at the start of 2024, and Western Australia ended it at the same time.
Did You Know?
Mountain ash trees can take more than 120 years to begin forming hollows suitable for wildlife.