A GONDWANA CONNECTION?
The Wollemi Pine.


In 1994 David Noble, an off-duty park ranger, abseiled into a shady, rugged gorge in an area now known as Wollemi National Park, 150 kilometres west of Sydney in
the colder part of the Blue Mountains. Intrigued by a small copse of a curious tree he found there, with its peculiar bark resembling bubbling chocolate, and dark green, fern-like neeedles, which were quite different from the treetops of sassafras
huddling beneath it, he brought back a specimen branch.

Excited researchers have found that it's a relic from the Age of the Dinosaurs. Notwithstanding numerous challenges - the many changes in climate since the
Cretaceous some 90 million years ago; the devastating extinction of species about 65 million years ago (including the Dinosaurs), the rise and fall of great civilisations, and the arrival of Europeans in Australia who made heavy inroads and changes to the countryside, and even the frequent but destructive bush fires in that area, this tree is one of nature's true survivors.

                Wollemia nobilis    Araucariaceae
Wollemia nobilis
Thought to be a separate branch of the Araucarian family of conifers, which have been around for about 215 million years, and were once dominant in the northern hemisphere forests before becoming casualties of the demise of much Cretaceous flora; the family was then only found in the southern hemisphere, consisting of the Hoop, Bunya and Norfolk Island pines.  The Wollemi pine appeared to
become extinct many millions of years ago with only a few pollen particles found in two-million year old Bass Strait sediments during oil exploration..
But all is not yet lost. After being hailed as the botanic find of the 20th Century and given the name Wollemia nobilis (Wollemi Pine), it was decided to gather the wild seeds and propagate new trees in a commercial plantation in Queensland which were then auctioned to raise much needed funds for further research.
Young trees were placed in botanic gardens and in certain National Parks in Australia to see how they could cope with various conditions.  Many more have now been produced for sale to the general public; thus making it more commonplace and greatly increasing its chances of a continued future.
Tasmania was once part of the great Gondwana continent (see Timeline) and even today has other plant species which are relics of that long ago era. Now it has a new "old" friend - one with great prehistoric mystique but hopefully a long life in a very different era..




Wollemia nobilis - new growth

New Growth
                        Resin protects the growing tips

Wollemia nobilis (resin covered tip)






Wollemi Pine cones





MORE ON THE WOLLEMI PINE AND ITS APPARENTLY PRIMITIVE PLUMBING
SYSTEM.


Researcher Geoff Burrows of  Charles Sturt University at Wagga Wagga, New South Wales, has said that the system of water movement in this now rare pine, may be the reason for the species' decline.  The pine has a remarkable reduction in the number of water-conducting cells near the base of each branch.  He explains, "It's a bit like connecting a drinking straw to your outside tap, then attaching your normal garden hose to the straw: the straw now limits the flow of water from the tape to the hose."

The small number of water-conducting cells means that the tree's branches are only loosely connected to the trunk and may explain why the Wollemi cleanly drops whole branches at the trunk with leaves attached, rather than individual leaves like all other trees.  It is also believed to be the only tree species in the world to produce branches that will never branch again.

Burrows says that the Wollemi's branch-dropping mechanism would have worked well in the Cretaceous, 60 to 80 millions years ago, when Australia was warm and moist. But as the continent became hotter and drier, the tree became less able to compete with newer species, such as eucalypts, which have much stronger water-supply structures and are better adapted to arid conditions.


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