Nursing an "Extinct" Tree Back to Health
Elizabeth M. Tasker
for National Geographic News
|March 5, 2003|
In 1994 a bizarre-looking tree previously known only from 120 million-year-old fossil leaves was discovered alive and well in a rugged gorge west of Sydney, Australia.
Fewer than 100 Wollemi pines exist in the wild, and scientists and horticulturists are undertaking a massive effort to cultivate additional trees to improve the species' chances of survival. By 2005/2006 more than half a million of them will go on sale worldwide as garden and indoor plants.
Discovery of a Living "Dinosaur"
Extensive forests cover the Blue Mountains, located 93 miles (150 kilometers) west of Sydney. Although the average elevation is only about 3,300 feet (1,000 meters), the mountains are rugged with many impassable cliffs and deep gorges.
The Wollemi wilderness is the most inaccessible area; a plateau with more than 400 plunging canyonsdeep chasms eroded in the soft sandstone, often only a few meters wide and filled with pools of icy cold water.
On a hiking trip in 1994, David Noble, an officer with the New South Wales National Parks and Wildlife Service (NPWS), noticed a grove of unusual-looking trees growing in a deep, sheltered rainforest canyon.
The trees had strange bark that looked like bubbles of chocolate, multiple trunks, ferny-looking leaves growing in spirals and were up to 125 feet (38 meters) tall.
Noble collected some foliage, and months of taxonomic research by botanists at the NPWS and Royal Botanic Gardens Sydney (RBG) followed. The tree was finally revealed to the world as a new genus and species, Wollemia nobilis in December 1994.
The discovery was the botanical equivalent of finding a dinosaur alive today.
"It was very significant that we'd discovered such a large plant living so close to Australia's largest city that is botanically unique, and something that scientists dream abouta link back to Australia's prehistoric past," said Cathy Offord, a horticultural scientist with the RBG and one of the first botanists to see the pine in the wild.
Relics of an Ancient Forest
Wollemi pines are members of the ancient Araucariaceae family, also known as Monkey Puzzle trees. These are plants of the southern hemisphere, and most are now found in isolated populations in South America, New Caledonia, New Zealand, New Guinea, and Australia.
Ancient pollen samples show that the Wollemi pine or its near relatives dominated the forests of the southern hemisphere for more than 100 million years. Dramatic changes to the world's climate about 2 million years ago led to their demise.
Miraculously, a small grove of Wollemi pines hung on in the deep and humid chasms of the mountains west of Sydney.
Because the pines have been isolated for millions of years, they provide a rare opportunity for scientists. Research has revealed that the pines are all genetically identical, a condition previously unknown among sexually reproducing organisms. Scientists are being forced to rethink genetic theory as a consequence.
The pines send up multiple stems from the base of the trunks, known as coppicing. Most of the trees have several trunks, but one massive individual has 160.
"We think the coppicing is why the Wollemi pine has survived," said Offord. "These younger stems are waiting to replace the main trunk if it gets damaged or dies."
Conservation and Propagation
Since their discovery in 1994, two more small stands of pines have been found in nearby gorges, bringing the total wild population to 76 trees and about 200 seedlings. Despite the additional finds, the Wollemi pine remains one of the rarest trees in the world, and this makes them particularly vulnerable to extinction from disturbance or disease.
"The greatest threat now is man, because it's such a fragile environment," said Offord. Strict protection measures have been introduced by the NPWS and RBG, who are jointly managing conservation and research.
The location of the pines is kept completely secret, and there is a AUD$220,000 (US$133,000) fine for anyone disturbing them. Only a very small number of researchers are allowed to visit the main grove, and they must follow strict quarantine measures such as changing their clothes to prevent the introduction of weeds or diseases, said Offord.
To reduce the temptation for people to try and steal pines from the wild, and to increase the total number of pines in the world, the management committee decided to propagate the pines for sale as garden plants. Birkdale Nursery, a private company, and the Department of Primary Industry (Forestry), both in the state of Queensland, were awarded the rights.
In 2000 a special high security facility was built near Brisbane, and 400 trees propagated by the RBG from cuttings and seeds were handed over.
"The propagation is coming along really well," said Barbara McGeoch, general manager of Birkdale Nursery. "We hope to have more than half a million pines available by the time they go on sale in 2005/06."
Royalties from sales of the pine will go to the NPWS and RBG for conservation of the Wollemi pine and other threatened plants in the wild, said McGeoch.
The pine has already entered Australian culture; it's part of the school curriculum, and songs have been written about it, said Offord.
"It just goes to show that you need to conserve forest areas," she said, "even if you think that you know them really well. You never know what you might find."
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