Botanic Gardens Trust, Sydney, Australia

Humans and rainforests

The arrival of humans

For at least 40,000 years, Aboriginal people regularly set fire to Australia’s vegetation cover. The burning produced a greater local diversity of plant and animal foods. This ‘firestick farming’ maintained a mosaic of vegetation in different stages of development including lush young regrowth. Fires in sclerophyll forests killed or damaged the trees along the edges of adjoining rainforests. Aborigines of northern New South Wales and Queensland, whose territories included large tracts of rainforest, used fire to make clearings in the rainforest for ceremonial purposes, to improve access and to increase the numbers of grazing wildlife.

By the time the first Europeans arrived in Australia, the rainforests had already survived a range of climatic stresses which led to numerous retreats and advances of their boundaries. The new settlers were more concerned with their own survival than protecting the natural vegetation. Their attitude was understandable. The forests seemed unending and stood in the way of establishing crops and pastures.

In the first two hundred years of settlement, three-quarters of the surviving rainforests were cleared. The remaining rainforests occupy an area only one third the size of Tasmania. Only half of these are free from significant human impact.

A wide variety of land management practices has taken its toll on the rainforests. This includes: logging; land clearance for crops including sugar cane, pumpkins, potatoes and corn; dairy farming; gold, tin and sand mining; beachfront and resort development; and access roads and airstrips.

‘Red gold' rush

Just two years after settlement, a hundred year rush on the rainforests was triggered by the discovery of one of the finest sources of cabinet timber in the world. The tall-shafted trunk of the softwood Red Cedar (Toona ciliata - formerly T. australis) was easy to work and could be floated down creeks and rivers to sawmills or waiting ships. Disregarding the limited nature of cedar supplies, timbergetters in New South Wales cut out most of the cedar by the 1860s. Ironically, at least half the timber they felled never made it to the mills because of wasteful practices, and later attempts to grow cedar in plantations failed.

Obstacle to progress

To the pioneering settlers who followed the transient cedar getters, the daunting ‘brush’ or ‘jungle scrub’ was an obstacle to progress. The Robertson Land Act of 1862 obliged settlers to clear the rainforest covering their small settlement blocks. Despite their size, the softwood rainforest giants were easier to fell than anticipated and burning the stumps stopped regrowth. The rich red soils beneath the rainforests failed in the long term to support successful crops or dairy ventures. Much of the soil fertility was initially lost when the rainforest was cleared and burnt. Soil erosion completed the task over the years, causing downstream siltation and flooding.

As far back as 1870, the loudest voices raised in protest against large scale clearing of rainforests for agriculture were those of the foresters. Ironically, some of the New South Wales rainforests they saved as sources of timber were later to be permanently reserved within national parks.

Rainforest timbers such as Red Cedar, Rose Mahogany and Coachwood have made an outstanding contribution to the Australian furniture industry since settlement. Over the years they have been used in the construction of coaches, aircraft, rifles, school desks, marine-ply for boats and decorative panelling in buildings such as Old Government House at Parramatta, the Opera House, the High Court and the new Parliament House in Canberra.

Because of heavy demands, plantations of Hoop Pine, Coachwood and other rainforest trees have been grown with mixed success. Attempts to establish plantings of the valuable Red Cedar have been thwarted by the predation of larvae of the cedar tip moth.

blackbean
Black Bean (Dastanospermum australe) was one of many rainforest plants eaten by Aborigines. The seeds required careful preparation to remove toxins. Today Black Bean seeds are being investigated as a source of pharmaceutical drugs. Illustration: Nicola Oram.

Front page news

When the battle for the Terania Creek rainforests burst so graphically into the media in 1979, it was the first time that many Australians had heard of the rainforest issue. But the conflict of interests between logging and conservation had been building for almost a century. With only 11 per cent of the State’s rainforests under protection, local residents and voluntary conservation groups were concerned that 60 to 90 per cent of all rainforest timbers logged were used to make disposable plywood for the construction industry.

Scientists questioned the long term viability of rainforests under the policy of selective logging.

Rainforest rescue

In 1982, pubic opinion polls showed that 87 per cent of the community favoured saving the rainforests if alternative employment could be found for the out-of-work loggers. Sixty nine per cent were unequivocally in favour of rainforest preservation. In early 1983, the New South Wales Government announced that 90,000 hectares of northern New South Wales rainforests were to be preserved as parks and reserves.

This increased the percentage of rainforests under protection in NSW from 11 per cent to 41 per cent.
At the same time, the Government stressed its commitment to find substitute woods and alternative employment. There were sound economic reasons for ceasing all rainforest loggings in 1983. Because rainforest timber stands were close to exhaustion, the associated timber industries already had to face the reality of finding other sources of timber and work in the not-too-distant future. Stopping the logging brought this change forward and, in doing so, saved the last stands of the rainforest.

In 1986, sixteen New South Wales rainforest areas were included on the World Heritage list.

In other states the position has also been much improved in the past decade. Most of Tasmania’s Cool-temperate Rainforest and Queensland’s Tropical rainforest is now conserved in World Heritage areas. However, in all states (apart from South Australia which doesn’t have any) substantial areas of rainforest remain under threat from logging, mining and grazing pressures.

Rainforest rebirth

A project that could take up to 500 years to show results does not usually attract enthusiastic support. Despite the need for such a long-term viewpoint, volunteer groups throughout New South Wales are helping to undo some of the damage of past clearing practices.

At Wingham Brush near Taree, a team of local regenerators under the guidance of Royal Botanic Gardens botanists was funded by the local council to rescue a local remnant rainforest from weeds.

The Lismore-based Richmond Valley Naturalist Club, with the help of the NSW National Parks and Wildlife Service, aims to double the area of existing rainforest in the 17-hectare Victoria Park Nature Reserve, a small remnant of the original Big Scrub.

Rainforest replanting does not just involve scattering the appropriate seeds and adding water. Regenerators have to provide conditions under which natural regeneration can occur, using surviving plants as local sources of seeds. The main objective of regeneration is to establish a canopy of fast-growing pioneer trees and vines that may live for 5 to 20 years. These shade out weeds that might otherwise smother the slower growing trees that can live for well over 300 years and dominate the rainforest.

bird
Rainforests support many native animal and bird species. Illustration: Nicola Oram.

Looking to the future

In the past, rainforests were chiefly valued for what could be obtained from them. Today they are valued for what they are. Rainforests protect unique plants and animals, fragile rainforest soils and the equality of water draining from the catchment. They also attract large numbers of Australian and overseas visitors who want to explore a complex and unusual vegetation community.

To increase greater public awareness and interest in the rainforests of New South Wales, Rainforest Information Centres have been established in Dorrigo National Park, Port Macquarie’s Sea Acres Nature Reserve, Minamurra Falls in Budderoo National Park, and in Gosford’s Rumbalarah Reserve.

To botanists, intact rainforests provide important clues to the evolution of the Australian flora. Rainforests largely escaped the fluctuating conditions that changed the face of the rest of Australia’s vegetation by surviving in moister sheltered locations along the Great Dividing Range.

As a result, the remnant rainforests provided long term stability. Some of the surviving rainforest plant species date back to Gondwana. Such survivors contain clues for botanists unravelling the origin and spread of flowering plants and the evolution of the characteristic ‘Australian’ vegetation.

The remnant rainforests in turn provide refuge for other forms of life. Because they are so complex, rainforests support a large proportion of Australia’s animal species.

Not all rainforest animals are permanent dwellers. Some are part-time and others migratory. For the endemic rainforest species, rainforests offer their only hope of survival.

Because some rainforests have existed unchanged for million so years, they support many unusual animals, including the gastric-brooding frog, tree kangaroos, the primitive musky rat-kangaroo and the chameleon gecko.

Nature's supermarket

Australia’s rainforests supplied the daily food and hardware needs of Aborigines living in and around rainforests for thousands of years before European contact. Today, Australia’s most successful rainforest food is the Macadamia or Queensland nut, which is grown commercially in Australia and Hawaii.

Other rainforest food plants are presently being studied to assess their suitability for cultivation.

Other products of our rainforests are the elegant Elkhorn, Staghorn and Bird’s Nest ferns which are grown commercially to meet the needs of gardeners.

User-friendly drugs

Rainforests of the world have traditionally produced a large proportion of the natural active ingredients used to make the drugs on chemist shop shelves. Desperate for relief, Australia’s European pioneers devised bush remedies to cure their aches and pains. Today, drugs derived from rainforest plants are used to combat lymphoid cancer, to improve eye complaints and to quell motion sickness.

With so little research completed in this field, the potential for discovering valuable new rainforest drugs is promising. 

Rainforest's last stand

To the first European settlers, rainforests were an acquired taste. While occasional travellers were sufficiently moved to write eloquently of their grandeur, their voice was but a faint cry in the wilderness.

The men who cleared the forests for agriculture or timber were more sparing in their praises. Their eyes and ears were closed to the enduring beauty of the rainforest. All they were aware of was the humidity, stinging trees, wait-a-while vines, leeches and loneliness of the ‘jungle scrub’.

Until the 1980s it was believed that our rainforests originated overseas and invaded the Australian continent across ancient land bridges. Contrary to earlier beliefs, we now know that rainforests once covered large areas of Australia and actually ‘parented’ the gum trees, wattles, waratahs and all the other plants which have long been regarded as the typical Australian vegetation.

Australia’s unique rainforests have at least come of age.