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The Jurassic Tree And The Lost Valley

James Woodford



06/07/1997

Sydney Morning Herald

36

Copyright of John Fairfax Group Pty Ltd



While scientists unravel the secrets of the prehistoric Wollemi pine, writes JAMES WOODFORD , the one conclusion they can state with any certainty is that humans pose the greatest threat to its continued survival. THE National Parks and Wildlife Service helicopter banked, slicing through cold air as it lifted away from a town in the Central Tablelands of NSW, carrying three of its five passengers in a blindfolded world of pink and white checks. Through the tea-towels tied over our eyes the dawn sun looked like a vague smudge of light and the only hint of a geographical feature visible through the material was a grey bumpy line - the mountains on the boundary of the 500,000-hectare Wollemi National Park. More than two years after the discovery of the now world-famous prehistoric Wollemi Pines, the Herald had obtained permission to visit the trees. On Tuesday this week, the Herald spent a day with NPWS and Royal Botanic Gardens staff who travelled to the site as part of a monitoring program. Before we left for Wollemi, the NPWS had insisted on the signing of a detailed consent form requiring absolute confidentiality about the location of the Wollemi pines, a new genus of tree found in August 1994. "The applicant agrees to use the phrase 'in a canyon in the Wollemi National Park' when referring to the location of the site," the consent form says. While rumours abound about the trees' location, the NPWS estimates that fewer than 30 human beings have visited the remote gorge, most of whom are scientists. Because nearly all were blindfolded during the trip there, only a handful of people are capable of putting a cross on a map.

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The explorer who accidentally found them during a weekend bushwalk, David Noble, an NPWS ranger, estimates that Wollemi National Park still boasts about 200 creeks that have never been visited by people. When the story broke in 1994, it seemed impossible that a 40-metre-tall new genus of tree, just beyond the boundaries of Sydney, had remained undiscovered for so long. By the end of the Herald's visit to the area it seems a miracle that it was ever discovered at all. * * * AFTER a period of time that was impossible to judge, the helicopter turned and dropped into a zig-zagging descent that completely baffled any remaining sense of direction. The blindfolds were removed only when the helicopter had dropped into the gorge and all landmarks were hidden behind the cliffs. The helicopter was now a tiny speck between the 400metre-high walls of a gorge filled, right to the base of both walls and off in a ribbon towards the horizon, with an almost unbroken carpet of rainforest canopy. David Crust, a senior NPWS ranger, pointed to the spear-like crown of the biggest Wollemi pine on earth, nicknamed "King Billy" and known to science as "tree one". Scientists estimate that King Billy first began poking its head above the canopy about the time of the Norman conquest in 1066. Images of King Billy travelled around the world when the discovery of the Wollemi pines was announced in the Herald in December, 1994. Its crown, emerging from the rainforest with prehistoric foliage unlike anything seen by science except in 91-million-year-old fossils, inspired the then director of the Royal Botanic Gardens, Professor Carrick Chambers, to say: "The discovery is the equivalent of finding a small dinosaur still alive on earth." Then the pilot swung the helicopter around and headed towards a ledge on a promontory sticking out into the gorge, where we were to be offloaded. The site is so rugged that no potential helicopter landing pad has yet been found. The pilot had to bring his aircraft to a hover a metre above the ledge, with only one skid over solid ground, while his five passengers clambered out to warnings that sudden movement would tip the machine like a canoe. Abseiling gear and equipment for a day of seed collecting were offloaded, then the helicopter was gone. Crust and a Royal Botanic Gardens horticulturalist, Graeme Errington, immediately began draping ropes into the canyon for two abseils that would take us through the rainforest's canopy and into a fairyland of ferns, fungi and a gloomy impenetrable darkness. The scientists who prepared the draft Wollemi Pine Species Recovery Plan estimate that the amount of light reaching the base of the cliffs where the Wollemi pines live is less than 10 per cent of that above the canopy levels. Some areas receive less than one hour of direct light per day.

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It is a dense forest of coachwood, sassafras, lilly pilly, possumwood, tree ferns, red gum and grey gum surrounding a pristine stream full of yabbies. Water vines 30cm across - that may have started growing before Europeans arrived on the continent - have formed tangled knots as big as a lounge room. Although fauna surveys are still incomplete, it is known that the site boasts bush rats capable of eating through plastic barrels, and a full suite of possums, gliders and antechinuses. From where we were dropped there is a 15-minute walk upstream to King Billy and the 39 other adult Wollemi pines. The pines are in two separate populations one kilometre apart. The southernmost colony is almost never visited by anybody, deliberately left alone to remain a reference point for research. About 100 metres downstream of the trees is a special disinfectant footbath where the group was required to sterilise shoes to prevent the introduction of fungi that are devastating Western Australian and Tasmanian forests with dieback. Tests have revealed that, while the site is rich with fungi unknown to science, including one that produces the anticancer drug Taxol, the deadly phytophthora fungus is absent. If it were to arrive, the pine could be wiped out. A few minutes after stepping through the footbaths, we arrive at the northernmost Wollemi pine - a tiny seedling that, like most of the 200 being monitored on the site, will be unlikely to survive for more than a few seasons. Because the pines are dependent on light, unless a hole forms in the canopy they are doomed. A senior plant ecologist at the Royal Botanic Gardens, John Benson, says that it is possible to understand the full ecology of a population of trees like the Wollemi pines only by thinking in terms of hundreds of years. Only one or two seedlings out of every hundred need to make it to maturity in order for the genus to survive in the gorge. One of the most vigorous Wollemi pines in the gorge - known as tree 11 -was able to launch itself skyward because a cliff collapse removed other competing tree species. Other juveniles get their chance if a tree falls down. Some seedlings cling precariously to rocks in the middle of the creek, where the light is good but the chances of holding on during a flood are grim. About 37 per cent of the population's viable seeds - about 4,000 are estimated to have been produced in 1996 - are eaten by rosellas and a huge swag fall into the creek and are simply washed away. Scientists at first speculated that this would help spread the species, but every nook and cranny within 15 kilometres downstream of the trees has now been searched and no seedlings or adults have been found. SINCE THE trees were discovered, horticulturalists have been working on propagation to establish populations safe from catastrophe. On Tuesday this week, Errington and Crust's job was to collect seeds for propagation, download data collected by on-site sensors onto a laptop computer, then leave as promptly as possible. The first stand of adult trees is surrounded by a strange collection of fine mesh material nets, several metres square, which serve as seed collectors.

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It takes Crust and Errington about two hours to empty the 19 traps. Then the data loggers are downloaded, giving weather details back to March -maximum and minimum temperatures, humidity and soil temperatures - allowing horticulturalists to provide propagated plants with optimum conditions. Errington says he knows it is a cliche but the grove has an incredibly 'Jurassic' feel about it. "I don't just think it's the fact that the trees are here; it's part of the Wollemi magic,&qout; Errington says. "I quite like the idea that something has been living down here, happily chugging away." Throughout the day, Crust and Errington comment that there is a different world beneath the canopy - a place that absorbs and surrounds visitors and foreign objects so completely that they become invisible to the outside world. Even the giant seed traps cannot be seen from above the canopy. Our allotted time among the trees skidded by. We'd arrived at the first seedling at about 9.30 am and we were fast approaching our scheduled rendezvous with the helicopter at 3 pm. As the last of the work was being wrapped up, a passenger jet flew above the gorge, descending into Sydney - for a moment the noise was a reminder that a city of 4 million people is just a couple of hundred kilometres away. On our way out, we scrambled up to a rock on the cliff, just above the canopy and level with King Billy, the only pine unashamedly obvious to the outside world. From this lookout, and for the first time that day, we were able to get a perspective on just how weird this organism called a Wollemi pine really is. Against the gun-metal olive greens of traditional Australian bush, the rich deep greens of King Billy look completely out of place. Says Crust: "It's the wrong colour, the wrong texture, it looks weird, unusual and distinctive." Its trunk is covered in millions of bizarre nodules which are remarkably similar in appearance to coco pops. After we had left the gorge, Dr Rod Peakall, a lecturer in the Division of Botany and Zoology at the Australian National University, reveals to the Herald his latest genetic research into the trees, which shows that each of the pines tested is identical. So far no genetic variability between one adult and another has been found.

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They are so similar that no other plant on this planet is known to have such a lack of diversity between individual specimens, Dr Peakall says. They may have become that way by one of the most drawn-out periods of inbreeding and isolation in the history of life. The Wollemi pines have been locked in their time capsule - their canyon - for a very long time, he says. In that time they have survived ice ages, fires, droughts and floods. About the only change a Wollemi pine has never before had to confront is a human, and how will it cope with that? "It seems to me that the only threat to Wollemi pines is the threat of humans," Dr Peakall says. THE LAW OF SURVIVAL PROBABLY no other issue has caused the NSW National Parks and Wildlife Service and the Royal Botanic Gardens greater anxiety than what to do with Wollemi pines. On the one hand, the trees appear to be at the end of their "window", slowly but inevitably heading towards extinction. On the other hand, protected by their little canyon, they have survived everything life has thrown at them -ice ages, unimaginably immense periods of isolation - and are thriving. The trees also have immense commercial value as a cult horticultural product potentially worth millions of dollars.

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The first attempt to grapple with these issues has been made in a draft report - the Wollemi Pine Species Recovery Plan - which outlines all known biological facts about the genus and how best to ensure its survival. However, the ethical problems posed by the discovery of Wollemi pines were summed up in a recent scientific paper by John Benson, senior ecologist with the Royal Botanic Gardens: "With relic species like the Wollemi pine, the question arises about the suitability of using the term "recovery plan". Recovery from what or to what? Should not the aim be to maintain the existing population and genetic variation? "Should we treat a flagship species like the Wollemi Pine differently from less well-known species? Should we allow translocated populations to be established to increase the likelihood of the Wollemi Pine surviving a catastrophe in the wild?" The recovery plan calls for a series of research projects - genetic, ecological, tolerance to fire, the best methods for cultivation and studies into the best methods of seed storage. The plan also requires the NPWS to co-ordinate with the Environment Protection Authority in the event of pollution or other environmental catastrophe. In the event of a disaster destroying the wild populations of the pines, seeds and seedlings now growing at Mt Annan Botanic Gardens may be used for a reintroduction program. But this would be only if the species had disappeared from the site for more than five years and if its decline had been due to human-induced threats, which must be effectively reduced before reintroduction.

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