The pine that time forgot
Visiting the last stand of the Wollemi Pine has to be one of the highlights of reporting for ABC Science. Mark Horstman still can't believe his luck as he abseils back in time.
With all the certainty of a four-year-old, my son Jarra reckons the dinosaurs didn't die out when a big rock fell out of the sky. Some went by ship to a faraway island, he says, where they still live happily ever after.
Despite the implausibility of a Cretaceous P&O cruise, I'm starting to think he might be onto something. Right now I feel like that island really exists.
Not one girt by sea, but an island of rainforest surrounded by sheer cliffs 200 metres high. I'm standing in the spongy humus and dappled shadows of a forest of strange trees, whose direct ancestors witnessed the dinosaurs' demise 65 million years ago...the Wollemi Pines.
But you won't find this gorge named on a map of Wollemi National Park, because since the discovery of the trees in 1994, it's location is a closely guarded secret. The aim is to protect the rare and endangered trees from vandalism, disease, and trampling. No more than twenty people have been allowed here in the last decade.
I'm the reporter (and first-time abseiler) in our ABC-TV Catalyst team of producer Paul Faint and cameraman Julian Mather, only the second film crew allowed to visit the wild Wollemis. We're flattered to be told that a request from David Attenborough was turned down, and we've graciously agreed to share our footage with the BBC.
It's taken a helicopter, a blindfold, an abseil, a quarantine footbath, solemn vows of 'cross-my-heart-and-hope-to-die', and careful negotiations with the NSW National Parks and Wildlife Service to get here.
Meeting the mob
Lugging heavy gear and gawping in wide-eyed astonishment, I clamber around a sandstone outcrop and realise that this rainforest looks like nothing I've ever seen before. With a dramatic flourish, NPWS manager Dave Crust introduces us to his real-life Jurassic Park. "Here you go. Meet Wollemia nobilis. The whole gang."
The entire family numbers only about eighty. Through the thick scrub and low light, I can see the neighbourhood stretching for just a few hundred metres ahead, hugging crevices and ledges along the creek.
It's the usual warm temperate confusion of coachwood and sassafras trees, water vines and tree ferns. But the alien elegance of the Wollemi Pines stands out like dinosaurs at a dog show. Their ancient radial symmetry, their greener colour, their fishbone leaves all contrast starkly with the form of their flowering competitors.
Wollemi Pine bark is the texture and colour of chocolate crackles, feeling thin and vulnerable to touch. Their leaves are springy like the Kauri Pine's, but not spiky like their other closest living relatives, the Bunya Pine and Hoop Pine.
Crusty (such is the trust we've built up) obviously enjoys seeing the reactions of the privileged few allowed to meet the 'Wollys'. He points towards the other side of the narrow gorge. "See the big guy sitting out the top of the canopy over there? That's King Billy."
At 38 metres tall and several hundred years of age, King Billy is the biggest Wollemi Pine on the planet. That doesn't mean it's the oldest, however. All of the trees have multiple stems like bamboo, some 'coppicing' more than 20 trunks out of extensive root systems.
How long one 'tree' can keep regenerating from the same roots remains a mystery - it could be many thousands of years. There's only one other pine, a Northern Hemisphere species, that grows the same way.
Defying evolutionary theory
Thanks to inbreeding and their preference for cloning themselves, the pines' gene pool is so shallow that no other plant has a lower genetic diversity. In fact, the DNA of all the trees is identical, more like one giant woody organism than a forest of individuals. A disease that kills one plant, like the root-rotting fungus Phytophthora, will kill the entire population.
The Wollemi Pines have a bet each way on the rules of natural selection. Small populations are expected to have low diversity due to inbreeding. On the other hand, conventional wisdom says you need wide genetic variety for species to be conserved. They've managed to survive despite themselves.
Even when they do have sex by wind pollination, it takes two years for their seeds to mature. The ten percent that are viable (and not eaten by crimson rosellas and glossy black cockatoos) may produce seedlings (if not buried by busy brush turkeys) that can spend fifty years in suspended animation waiting for a gap in the canopy to appear.
My inner Gardener is in conflict with my inner Ecologist. Looking around at the gatecrashing angiosperms crowding out the embattled conifers in this World Heritage national park, I'm fighting an overwhelming urge to get started on some serious pruning. And while I'm at it, maybe a bit of clearing and some strategic planting in a nearby gorge?
"That's a really interesting sort of philosophical question," says Crusty, choosing his words carefully as he recalls national park policy about only fixing problems 'which can be directly attributed to human interference'.
"Gardening in national parks is a difficult one because we don't really know what the longer term impacts of that sort of activity are going to be. It may well be an option in the future to maybe create some openings in the canopy to encourage some seedling growth."
Traders of the lost park
Meanwhile a forestry nursery in Queensland has been licensed to cultivate them for domestic and export markets. When half a million go on sale next year, the rationale is there'll be less incentive for poachers to raid the park. Royalties will also fund conservation programs.
We don't know why the Wollemi Pines only grow in this deep gorge and therefore why they've become so vulnerable, but time and chance have a lot to do with it. This is one species that we haven't made endangered.
However as climate change drives up temperatures and sucks away rainfall in south-eastern Australia, this forest will be under greater stress. We may end up being guilty of some 'human interference' after all.
Climbing back up the wall of the gorge, we emerge into an opposite world where dry sandy soil grows casuarinas, banksias, and grass-trees. Dave looks across the canopy and down towards the sound of flowing water, where the sun only manages to reach for four hours a day.
"We've got seedlings down in the grove that are thirty centimetres high that are probably close to twenty-five years old, and one foot in the wrong place could wreck them."
The location of this magnificent place is known to some groups of hard-core bushwalkers and canyoners. Dave Crust relies on their goodwill and common sense to keep the secret to themselves. Curiosity is high, and it will take some decades yet for the tame Wollemi Pines in the outside world to become as tall as the wild family.
"There's certainly still going to be the challenge for some groups to try and come in to the Wollemi sites in the wild. All I can say to those people is that this is a really fragile, delicate, tenuous existence. Potentially, it's just clinging to life."
Published 19 May 2005