Nothofagus: relics from Gondwana

Nothofagus moorei - Antarctic beech in Border Ranges National Park

Nothofagus moorei: walking through the Nothofagus forest transports you to another world. (Image: TalkingNature.com)

If you’ve ever walked through a forest of ancient Southern Beech (Nothofagus spp.) you can be forgiven for believing that you have just stepped into another world. You often find these trees growing as rings of giant trunks, covered in hundreds of epiphytes and mosses, but don’t be fooled.

The rings of trunks are just the one tree! It’s called coppicing; the tree sends out new shoots radially from the base of the original trunk, and these shoot eventually grow into clones of the parent tree forming a ring of tunks, all belonging to the one tree.

These circles of moss laiden, gnarly, 50 metre high trees, coupled with the mists of high altitude forests create an atmosphere of ancient druid forests. Almost mystical. But in reality, these forests are from a world that existed long before Gandalf and the druids.

Coppicing - Nothofagus - Antarctic beech

The circular growth patterns of Nothofagus are the result of coppicing.(Image: TalkingNature.com)

The southern beech forests evolved some 100 million years ago, when dinosaurs roamed and Australia was still part of the super-continent, Gondwana. Between 160 and 65 million years ago Gondwana split apart, forming today’s southern land masses: Antarctica, South America, Africa, Madagascar, Australia, New Guinea, New Caledonia and New Zealand.

Nothofagus provide a classic example of how continental drift influenced species distribution. As the pieces of Gondwana moved to their present positions, they carried these ancient trees with them. That’s why Nothofagus forests are only found in South America (Chile & Patagonia), New Zealand, Australia (Tasmania and from Victoria to southern Queensland), New Guinea, and New Caledonia.

Fossilised pollen grains of Nothofagus have also been found in Antarctica – showing that Antarctica was once warmer than today, forested and connected to the other southern land masses.

Being on different continents for thousands of years has let these trees evolve independently but they are still classed as the one family (Nothofagaceae).

Conditions in Australia 65 million years ago were temperate and moist with high rainfall. Nothofagus and other rainforest species were widespread across the continent and fossil evidence suggests that these Gondwanan forests hosted a huge diversity of plants and animals. As Australia continued to move northward the climate got warmer and drier. The Nothofagus forests retreated to the moister east coast and the highlands.

Since then, European settlement, land clearing for agriculture and logging of the forests has reduced the Nothofagus to small fragments of forest throughout south eastern Australia, mainly in national parks.

There are three species of Nothofagus in Australia. Stands of Nothofagus cunninghamii (Myrtle beech) exist in the Tarkine Forest of Tasmania, an area well known for its ancient gondwanan forests, but an area yet to receive national park or world heritage status. There are also some small stands of this species in the Great Otway National Park, in Victoria.

The deciduous Antarctic beech (N. gunnii) also occurs in Tasmania and is the only deciduous tree to have evolved in Australia.

The Antarctic beech (N. moorei) is found between Barrington Tops National Park in New South Wales and Lamington National Park in southern Queensland. Almost all of the forest fragments of this species are protected as part of the Gondwana Rainforests of Australia World Heritage Area.

When Australia was covered by Gondwanan forests, Nothofagus supported a great diversity of life. So we ask, do today’s fragmented forests still support a high level of biodiversity?

The patches of Nothofagus forest throughout NSW and Qld still have an extremely high conservation value and provide habitat for more than 200 rare and threatened plant and animal species, including the giant barred frog (Mixophyes iteratus). Nothofagus forests within the Border Ranges National Park in northern NSW support the greatest concentration of frog, snake, bird and marsupial species in Australia [1].

The forests within the Gondwanan Rainforests of Australia world heritage area support more than 400 species of plants, including 50 species of climbers and 40 species of epiphytes (plants that grow on other plants) [2]. In Tasmania, the Nothofagus forests of the Tarkine also support an enormous array of fish, amphibians, reptiles, birds and mammals.

Mixophes iteratus

Mixophes iteratus: Nothofagus forests support a great diversity of organisms in Australia. (Image: TalkingNature.com)

So yes, despite being fragmented and isolated, Australia’s Nortofagus forests are very biodiverse.

It’s reassuring to know that some protection is now in place for Australia’s remaining Nothofagus forests however, many of these forest fragments are surrounded by fire prone eucalypt forest and agricultural areas.

Nothofagus are slow to recover from fire, unlike Australian eucalypt species, which have adapted to Australia’s hot, dry climate and fire regime [3]. Climate scientists predict the intensity and frequency of bush fires in Australia to increase with slight changes in regional temperature (1 – 2°C). Unfortunately this is bad news for Nothofagus because they are slow to regenerate. Increases in fire frequency may threaten the existence of these ancient forests in Australia.

So next time you’re walking through these Gondwanan forests and see a ring of trees, remember they’re probably just one individual of an ancient species with relatives in other distant southern lands.

And remember…keep TalkingNature going – visit our sponsors or browse our online store TalkingNature.com.au, and help yourself and your kids, nieces and nephews explore, understand and restore nature.

References

[1] Gondwana Rainforests of Australia World Heritage Area

[2] http://www.publish.csiro.au/paper/SB9930429 (CSIRO 1993)

[3] (Journal of Ecology) http://www3.interscience.wiley.com/journal/118509737/abstract

13 thoughts on “Nothofagus: relics from Gondwana

  1. Wow, these are striking trees. I’ve never seen a forest quite like this, but I have certainly added it to my list of “forests to visit.”

    We have lovely, lush forests in the Pacific Northwest as well – this is a superb time of year for mosses.

    Thanks for sharing Ruth!

  2. They truly are great forests. I have visited some in Tasmania and New Zealand.

    Though you missed an important aspect. After retreating ‘to the moister east coast and the highlands’ I think you’ll find these forests further declined prior to european settlement. Sometime after the breakup of the Australian and Antarctic continents, the eucalypt evolved as a rather invasive and hardy species that was able to displace a lot of existing forest. It was greatly advantaged by fire and may have been assisted in this respect by the arrival of humans ~40,000 years ago. Fortunately a lot of remaning myrtle strands are located in moist gullies where they are relatively safe from bush fires.

    No doubt a lot of damage has been done to myrtle forests since the arrival of europeans though. A lot of damage remains to be done through logging forests, particularly where clear-felling occurs.

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  4. I have visited and/or worked in all of the Nothofagus forests in Australia and they always impress with their beauty but even more importantly to know they are but tiny relicts of once much more widespread forests across Gondwana. So there is no risk that these relict forests on mainland Australia and Tasmania are important for conservation.
    But we are missing out on a major part of the story unless we acknowledge the even greater extent and greater biodiversity of the relict Nothofagus forests on the island of New Guinea. Remember that New Guinea has only been an island since separated from Australia by rising sea levels some 6-7,000 years ago – a very short time in the 65million year story of separation and northwards drift of the Australian plate from its sibling Antarctica. Up to then, the extensive Nothofagus forests in New Guinea were a part of the Australian story of Nothofagus. There are some 14 species of Nothofagus in the high mountains of New Guinea compared with the 4 in Australia. Some New Guinea species form magnificent dense pure stands of forest as beautiful as any on mainland Australia or Tasmania.

    Whilst we have done an excellent job of protecting a majority of the relict Nothofagus forests in Australia, spare a thought for their poor state of conservation on the island of New Guinea. Some fine examples of Nothofagus forest have been protected in Lorentz World Heritage area in Indonesian New Guinea (Papua Province) but the security of these forests is not guaranteed given the illegal logging and disease. In Papua New Guinea for all intents and purposes there is little or no significant protection of Nothofagus forest. Most Nothofagus forest in PNG is not presently accessible for logging but this may not always be the case. Increasing fire incidence is causing deforestation.

    And while still on New Guinea, there are a lot more Gondwanan plants than the 14 Nothofagus; there are many species of Gondwanan conifers which have their closest relatives in Tasmania, New Zealand and Chile.

    The Nothofagus story is truly fascinating but lets not forget that a large chapter of the story of Nothofagus, indeed Gondwanan plants, on the Australian tectonic plate is found across Torres Strait in New Guinea and deserves a lot more of our attention.

  5. Fascinating, I wonder if there are any Wollemi pines hiding in PNG?

  6. any body thinking of going to see the beech trees remember it is prone to rain in the summer months and can get very cold
    there are park fees to be paid but allow a few days to see all of the park
    that will mean a tent and camping gear
    the views are stupendous and some walks should be taken as well
    nights are very cold and cold camping gear should be taken even if 40 degs cel in brisbane you will freeze at night but for all the miscomfort dont miss the trip of life time
    enjoy

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  8. I am really interested in painting these wonderful Antartic beech, but have only seen them in pictures. I am a botanical artist and have painted mainly the small plants of the Cumberland Plain in Western Sydney. I hope to go to the Barrington Tops sometime. Sonia Bennett. We must save our forests from destruction.

  9. Wow, interesting stuff! We wanted to plant a tree in honor of our Aussie mom who recently passed. Our climate here in the Midwest does not work for this tree and after reading this article, I am sorely disappointed, although reading about the Nothofagus has brought to mind visions of a future magical encounter.

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