The deciduous beech, also known as ‘Fagus’ (Nothofagus gunnii), is Tasmania’s only native tree to lose its leaves in winter, providing impressive displays of autumn finery. The tree is found only in Tasmania, and forms part of an ancient Gondwanan Southern beech genus, with close relatives in mainland Australia, Papua New Guinea, New Zealand and South America. It was first described in 1851 by Joseph Hooker from specimens collected by Ronald Campbell Gunn (hence the species name, gunnii) in the vicinity of Mount Olympus.
Some Antarctic fossils look very similar to today’s living species. In Tasmania, there is fossil evidence that many different Nothofagus species lived during the Eocene period, approximately 35 million years ago, including N. gunnii and its close relative, the myrtle (N. cunnighamii). However, only these two have survived until today.
Although long-lived (some trees have been dated to 350 years old), this species usually only grows to the size of a shrub or small tree, with a maximum height of 6–8 m. This may be due in part to the poor soil and harsh climate of its alpine habitat where it often forms an impenetrable mass – and is referred to by bushwalkers as ‘tanglefoot’. Exceedingly slow-growing, it does not recover well after fire and, once burnt, a population can only reestablish itself from the soil seed bank, or by either layering or seed dispersal from nearby areas. If fire destroys the seed bank, that population does not recover and becomes locally extinct.
Displays of yellow N. gunnii autumn foliage have been depicted so often in books, calendars and posters about Tasmania that they have become a part of our identity. Trips to see the ‘turning of the Fagus’ have long been a popular ANZAC Day (25 April) pastime.
Photograph by Miguel de Salas