Aussies Plan to Revive Rain Forest

In the 200 years since the first Europeans settled in Australia, about three-quarters of the continent’s rain forest has been felled.

Now, with the help of NASA know-how and computer technology, Australian botanists plan to recreate a rain forest under a nine-story envelope of steel and glass.

The Adelaide Botanic Gardens has built the largest conservatory in the Southern Hemisphere--and the largest in the world outside Europe--to redress the ecological imbalance and to educate Australians about the importance of rain forests.

“It’s a wonderful state-of-the-art machine for creating plants,” said Chris Steele-Scott, marketing officer for the gardens. “It should delight people and teach them how important it is to preserve what’s left of the world’s rain forest.”

The conservatory, opened in early December, was chosen as the south Australian city’s contribution to 1988’s nationwide celebrations of 200 years of white settlement.

Local architect Guy Maron spent $5.4 million constructing the slim glass house, which resembles a stretched version of the Sydney Opera House’s “sail” roofs.

The steep pitch of the 90-foot-high roof helps reflect the sun during Adelaide’s hot summers while sensors on the inside of the roof regulate the light, temperature and humidity within.

“It’s a very clever building in its efficient use of technology and takes the science of botanical gardens a step further,” said John Simmons, curator of the Royal Botanic Gardens in Kew, London, who was present at the opening.

Computer-guided windows control air flow while more than 1,000 special water nozzles in the roof provide humidity, cloud cover and ensure the temperature stays within the required range of 60 to 90 degrees.

In an emergency the nozzles, which were developed by NASA for the U.S. space program, can achieve complete water vapor “white-out” within the conservatory in three minutes. Two boilers will provide heat in cold weather.

Flexible rubber joints between the sheets of roof glass also act as gutters for rainwater which will be collected and filtered three times before being used in the building.

The conservatory, the largest in the world outside the Kew Gardens in London and one in Frankfurt, is landscaped to simulate an undulating rain forest, with the floor covered with six feet of rich soil.

Only plants from Australia, Indonesia, Papua New Guinea and Pacific islands will be used.

“We thought it appropriate to address local conservation issues, which is unusual because most conservatories try to show plants from all over the world,” said Steele-Scott.

Australia was once part of the great supercontinent known as Gondwana. By the time Australia severed its last Gondwanan links with Antarctica 50 million years ago, rain forests covered much of the land.

Plant fossils show the small areas of rain forest that remain in Australia are remnants of this ancient vegetation. Less than 0.1% of Australia’s three million square miles now supports rain forest.

Tough pioneer plants and palm trees have been planted in the conservatory’s soil and are expected to give a canopy of shelter within a short while, allowing more delicate and exotic plants like orchids to be introduced. Eventually there will be up to 4,000 rain forest plants.

Gardeners will not interfere with the growing process, leaving leaves and fallen bark to pile up on the ground.

“But we will have to regularly substitute palm trees,” Steele-Scott said. “These present trees will be pushing out of the top of the building within a few years.”