The changing of the Fagus

Click here to view a video of the Fagus

 

 

Autumn at Cradle Mountain is especially spectacular thanks to the deciduous beech (Nothofagus gunnii). Best known as fagus it is also called tanglefoot, as can be ruefully confirmed by bushwalkers who get caught up in its twisted, ground-hugging branches – so beware!

Fagus’ claims to fame include being Australia’s only cold climate winter-deciduous tree and that it is found nowhere else in the world but for many people it’s the tree’s spectacular range of autumn colours, from rust red through to brilliant gold, during late April and May that have pride of place.

Around 100 million years ago, when Tasmania was part of the supercontinent of Gondwana, the forerunners of Nothofagus first appeared. When Gondwana began to split, Nothofagus (or Southern Beech) was common in what would later become South America, New Zealand, Antarctica, Australia and their near neighbours.

it was the present distribution of Nothofagus that first suggested to scientists these landmasses might once have been joined. The species of Nothofagus most closely related to fagus are found in South America and New Zealand, strongly supporting the suggestion that Tasmania was formerly linked to those landmasses. Just why fagus is the only cold climate, winter-deciduous Australian tree derives from that ancestry.

 

Losing leaves in autumn is a response to long dark winters. The leaves are unable to photosynthesise, due to the lack of sunlight, so the trees shut down until spring. As Gondwana split and Australia drifted northward on its own, the winters became lighter and other groups of plants, including eucalypts, started to dominate a drier, sunnier Australia.

 

Only in the remote, wet highland areas of Tasmania, where losing your leaves is still a good defence against winter frosts and snow, has this rare Southern beech survived to thrill visitors each autumn.

 

Fagus usually grows to no more than two metres and prefers cool, damp places, so is often best seen in remote highlands but non-bushwalkers can find some very accessible stands of fagus. Some of the best fagus is found around Cradle Mountain and the Loop Track, which circles Dove Lake, is an easy two hour walk that passes through some patches of fagus. The even easier Weindorfers Forest Walk also offers easily accessible fagus, including trees that are much taller than the more usual stunted alpine form.

 

One of the most spectacular displays of fagus is found around Crater Lake. A couple of hours return walk from Dove Lake carpark, the sight of the steep slopes of the cup-shaped lake covered in brilliantly coloured fagus makes it well worth the effort. Be sure to take suitable clothing and fill in the walker log books.

 

Protecting a unique plant

 

There is less than 10,000 hectares of fagus growing in the whole of Tasmania - a tiny fraction of the wooded areas. Most of it is in highland areas above 800 m where rainfall is greater than 1800 mm.

 

Absence of fire is a key factor in the survival of fagus as, in contrast to many Australian plants, the deciduous beech is very slow to regenerate after fire. In some circumstances it may never recover from burning and other, less-susceptible, species take over. This makes the protection of the habitats of fagus crucial.

 

There is still much to be learned about fagus but one tree is known to be more than 350 years old, showing the slow growing tree can survive and thrive in these harsh conditions for a considerable length of time.