Forest destruction brings irreversible changes

Press, 9 December 1988, Page 13

Forest destruction brings irreversible changes

By

JANE DUNBAR

Colour photographs from World Wide Fund for Nature

The destruction of tropical rainforests around the world is endangering the planet’s ecology, and New Zealand must take a share of the blame.

Last year, this country imported $16.5 million of tropical hardwoods. The timber was used mostly for decking and outdoor furniture.

About 90 per cent of the timber came from South-East Asia, where the destruction of forests is having dire social and environmental effects. Rainforests round the world are being destroyed with unprecedented vigour. In the 19405, about 16 million sq km of tropical rainforest was still standing. Forty years later, 7 million sq km have gone, leaving 9 million sq km of forest. Most of it is found in Latin America, SouthEast Asia, and West Africa. “It’s a question of global survival,” says Dr Andy Buchanan, of the University of Canterbury Civil Engineering Department. Irreversible changes to the world’s ecology are taking place at an alarming rate, he says. Even the international timber industry is starting to be concerned about the plight of the forest, says Dr Buchanan, who is a timber specialist. A forestry plan “to save Asia’s forests” was recently published in one of the industry’s major magazines, “World Wood.”

In an attempt to help spread the word, Dr Paul Broady, of University of Canterbury’s plant and microbial science department, devotes several lectures to the subject. At least a quarter of a million square kilometres of rainforests are being “destroyed, degraded or impoverished” each year, with appalling consequences, he says. For this, he blames the Western world as much as he does Governments directly responsible.

Brazil, for example, is so severely in debt to Western banks it can barely pay the interest owed. To try to keep up with payments, it sells the products of rainforest destruction.

Consideration could be given to deferring the debts, Dr Broady says, and.. people should think twice before using something from a tropical forest. Japan, the United States and Europe are the major consumers of rainforest products. Japan conserves its own forests very carefully and imports more than 50 per cent of the world’s tropical timber exports.

Imported timber there is mostly used for building, furniture, pleasure boats, even coffins and disposable chopsticks. It is a vicious circle, says Dr Broady. Not buying the timber could put developing countries further into debt.

Then there is the corruption problem. A recent “Foreign Correspondent” story on television said that in Malaysia, forestry concessions covering millions of hectares and worth billions of dollars have been given to the relatives and political allies of those in power. The world’s largest tropical log exporting areas are now the Malaysian states of Sarawak and Sabah, on the island of Borneo. Meanwhile, the destruction of rainforests world wide is increasingly the subject of international controversy. Anthropologists are worried about traditional forest dwellers, meteorologists are con-

cerned about the world’s weather, and botanists are anxious about vanishing species. Primary rainforest is extremely valuable for its biological diversity, says Dr Broady.

More than 100 different tree species can be found in one typical hectare of Amazonian rainforest, and only a kilometre away, 50 per cent of the trees are different species again. In more temperate forests, only 12 to 25 species can be found over thousands of square kilometres. More than a third of the world’s plants are found in tropical rainforests even though those forests cover only six per cent of Earth. In a piece of rainforest in Ecuador, 1025 plants species can be found in 1.7 sq km. By comparison, in New Zealand 1800 plant species are found in 270,000 sq km. In 7 sq km of Costa Rican forest, you can find 320 tree species, 394 bird species, 104 mammals, 76 reptiles, 46 amphibians and 143 butterflies. Once primary forest is logged, secondary forest, can be regenerated in 10 to 25 years, admits Dr Broady. But it will probably never have the original forest’s rich diversity, a diversity important to the planet’s future.

Forests are a source of genetic material. They contain, for example, wild varieties of some crop plants. If disease hits crops, a variety with resistance to the disease could be found in the rainforests and transferred to the affected area.

Forests are also an important source of medicines and foods. About 6500 plants are used by traditional healers in South-East Asia, says Dr Broady. Which of these could be useful to us? He points to the example of the rosy periwinkle, originally found in the wilds of Madagascar and now used extensively for leukemia treatment.

Many of our foods originally came from the forest — such as mangos, avocados and bananas — yet we use only a tiny percentage of the potential. All sorts of 'new foods could be developed, he says. Natural sweeteners and pesticides, fibres, canes, resins, waxes, dyes and natural rubber are other important forest products, all of which can be harvested on a sustainable basis, says Dr Broady. Such use of forests is the way to save them, he argues — not locking them away, but convincing people that using forests in a sustainable way is better than the one-off economic benefits of non-sustainable logging and clearing for cattle ranches. Until the world acknowledges the “real” value of the forest, the destruction will continue. It is easier to put an economic value on timber and chips than on food, medicines and genetic material.

The stabilising effect of forests on the environment and climate is another important factor to be taken into account, says Dr Broady. Rainforests protect the soil from erosion. Deforestation exposes the soils to the full force of tropical downpours, and they can be washed away. Downstream effects due to siltation include damage to fisheries and offshore coral reefs. Floods and droughts become more likely once forests are cleared.

Tropical rainforests are important for recycling of water and control of carbon dioxide levels in the atmosphere.

Meanwhile, commercial logg-

ing is responsible for the clearing of 45,000 sq km of rainforest a year. Fuelwood harvesting gathering accounts for 25,000 sq km, cattle raising 20,000 sq km, and forest farmers 160,000 sq km. If the loss continues at this rate, the rainforest will all be gone in 40 years, says Dr Broady. Indonesians have reduced

their export of raw logs recently. Processing logs in their own country generates more revenue, , and fewer trees can be cut for the same economic return.

The felling of forests for cattle-raising occurs mostly in Latin America, says Dr Broady. Ranchers move into the forest, fell it, burn it, and pasture comes up. But clearing the land for cattle grazing is often barely productive. In the first year, one head of cattle is grazed per hectare. The land’s fertility can decline so rapidly that in five years it is reduced to one head per 5 hectare. Toxic weeds can invade the area and kill the cattle. Farmers move off to new forest areas.

It is again mostly Western countries, and increasingly Japan, who are the main beef consumers, says Dr Broady. And of course there is also the involvement of multi-nationals — Goodyear, Dow Chemicals and Volkswagen all, for example; have large rainforest interests. The 300 million people who live in or near forests throughout the world use 180 million tonnes of fuelwood each year. "Slash and burn” forest farming has been traditional in some parts of the world for centuries. But with population expansion the forests are increasingly unable to support those farmers, says Dr Broady. This is exacerbated by social and economic pressures. More people move into the forest after being pushed from their land by Governments, banks and large landowners; 250 million people are now subsisting in this way. A British magazine, “The Ecologist,” recently started a worldwide petition that proposes a four-fold plan to save the forests. This includes exchanging Third World debts, by international agreement, for the guaranteed protection of the world’s tropical rainforests. It seeks the phasing out of destructive development programmes, such as ranching schemes, colonisation and road-building.

The petition will be presented to the United Nations, calling for an emergency meeting. To Paul Broady, the most effective ways of saving the forests will be schemes which use what is left of them on a