Only One Planet




Rainforest

World map of tropical rain forestsThe Tropical Rainforests are probably 60 million years old and cover about 1,000 million hectares of in the world - more than a quarter of the total World forest cover of 3,869 ha (figures from the Food and Agriculture Organisation of the United States survey 2000). That's in the region of 8.3% of the total land area of our planet, but this figure belies the extraordinary role which they play in the conservation of biodiversity and regulation of the World biosphere. They are the home to more than 13 million distinct species of plants and animals - that's more than half of the world's total number of species. These tropical forests contain:

  1. 90% of the world's invertebrate species
  2. 70% of all vascular plant species
  3. 30% of all bird species
The diversity is truly staggering. In one 52 hectare area of Sarawak, Malaysia, 1200 species of tree have been identified. Compare that with the 700 species found in the entire area of the United States!

THE DESTRUCTION
Currently 14 to 16 million hectares are being destroyed every year. That equates to about 30 hectares (75 acres) per minute! It is estimated that this is costing the World a species extinction rate of 100 to 140 species per day or 3-5% of the total world biodiversity pool every ten years! (This is because many of the species found in the rainforests are unique to a specific area and are very interdependent on one another for survival.)

There is now only a third of the area that there was in 1800, although the highest rate of destruction has occurred in the past 50 years.

WHY ARE THEY BEING DESTROYED?
The three main reasons for the rainforests being cleared:

  1. Planting subsistence crops (60%)
  2. Logging for paper, building timber and fuel (22%)
  3. Commercial farming & grazing land for cattle (11%)

Pie chart of causes of rainforest deforestation

A UNIQUE ASPECT OF THE RAINFOREST
One of the peculiarities of the rainforests is the poor and thin layer of soil. In theory, a normal ecosystem would struggle to survive on such land. However, the rain forests have evolved their own "nutrient recycling". Most of the ecosystem's nutrients are present in the plants, rather than the soil; over 80% in fact. Under the conditions of high temperatures and humidity and with an unbelievable number of living organisms at work, leaves falling to the floor of the rainforest decompose within six weeks, making their nutrients available in record time (as opposed to a year in a temperate zone deciduous forest).

WHAT DOES THIS MEAN FOR THEIR FUTURE?
Well, there is a major repercussion to this unique nutrient recycling. When trees and vegetation are cleared and taken away the systems nutrients go with them, ending 60 million years of development and leaving very little in the way of soil nutrients. As a result, the farmer or rancher who clears the forest very quickly exhausts the meagre nutrient resources remaining in the soil. The people who farm these areas are very poor and do not replace the nutrients and so have to move on to clear further areas ... and so on and so on. And because the soil is so thin and poor it is very quickly eroded by the rains and lost.

For these reasons it is very likely that, once an area of rainforest is cleared it can never be truly replaced.

That said, their are many scientific efforts going on around the World, investigating sustainability of the forests and ways of revitalising cleared areas.

WHAT IS THE IMPACT ON THE EARTH?
I've already mentioned the loss of rainforest species, which means a depletion of the World gene-pool and the resultant loss of biodiversity. This also means the loss of countless undiscovered drugs and remedies, as explored in the next section.

Another very important point is that the trees of the rainforest act as vast reservoirs of carbon. When they are burned or cut down and left to rot they release huge amounts of carbon dioxide into the atmosphere, contributing to the greenhouse effect. In fact, this is the second highest contributor to the greenhouse gasses at around 25%.

WHAT IS THE IMPACT ON MANKIND?
The rainforests are incredible reservoirs of natural chemicals which the plants and animals have been developing for millions of years to aid them in their defenses against disease, infection, predators, and pests. Mankind has just begun to scratch the surface of how these compounds can benefit it. Tropical forests have been the source of 60% of the anticancer drugs discovered in the last 10 years. Already 25% of the drugs in use in Western medicine are derived from rainforest plants, and yet we have examined only 1% of the forests' total potential. We have to ask ourselves: "With every hectare of forest cleared today, what possible miracle drugs are being lost forever?"

Here is a table of just some of the drugs currently used, which were derived from rainforest vegetation:

 

DRUG USE
Cortisone active ingredient in birth control pills
Curare muscle relaxant for surgery
Diosgenin sex hormones, birth control pills, steroids, asthma and arthritis treatment
Neostigmine used to treat glaucoma; also provides a blueprint for synthetic insecticides
Novacaine, cocaine local anesthetic; cocaine; also served as a blueprint for less toxic and less addictive anesthetics
Quassia insecticide
Quinine anti-malarial, pneumonia treatment
Resperine sedative, tranquilizer
Rotenone* pesticide, flea dip, eradicates Colorado potato beetle, used to poison fish
Strophanthus heart disease
Strychnine emetic, stimulant
Turbocuarine Originally used by natives to poison arrow tips. Muscle relaxant for surgery; to treat muscle disorders like Parkinson’s disease and multiple sclerosis. Cannot be synthesized in the lab.
vincristine & vinblastine several forms of cancer including acute leukemia, advanced breast cancer,  Hogkin’s disease

* also known by the catchy little name 1,2,6,6a,12,12a-hexahydro-2-isopropenyl-8,9-dimethoxychromeno[3,4-b]furo[2,3-h]chromen-6-one

In Sarawak a single species of tree, Calophyllum lanigerum, is being studied for extracts which scientists have high hopes for treating HIV and AIDS as well as tuberculosis. While it will be some time before the benefits are seen, if the extract eventually becomes a drug it could earn $300 million a year.

RAINFOREST NEWS

August 2002 - Brazilian President Fernando Henrique Cardoso announced on the 22nd August that the country is establishing the largest rainforest national park in the world as the country's contribution to the World Summit on Sustainable Development. Covering 3.8 million hectares (9.4 million acres) of the northern Amazon along Brazil's boundary with French Guyana, the Tumucumaque Mountains National Park shelters rare jaguars, harpy eagles and 12 percent of all primates known to exist in the entire Brazilian Amazon. WWF is allocating US$1 million to help the Brazilian government implement the park as part of the Amazon Region Protected Areas initiative (ARPA), an unprecedented collaborative effort to help fulfill the Brazilian government's promise to protect the Amazon. Tumucumaque means "the rock on top of the mountain symbolizing a shaman's fight with the spirits."

July 2002 - In an agreement, called a "debt-for-nature swap", the USA has canceled $5.5 million of Peru's debt to them, saving the Peruvian government about $14 million in future payments. Instead, Peru will pay $10 million in local currency into a trust fund in Peru that will be used for critical conservation work in 10 rainforest areas, covering more than 27.5 million acres. Peru has more than 20,000 species of vascular plants and nearly 1,800 species of birds, many of them found nowhere else in the World. The World Wildlife Fund, The Nature Conservancy and Conservation International together contributed more than $1 million to the project.

June 2002 - Conservation International announced that Marc Van Roosmalen, a Dutch scientist working at Brazil's National Institute for Amazon Research in Manaus, 1,800 miles northwest of Rio de Janeiro, has discovered TWO new species of monkey. Conservation International's President Russell Mittermeier said "This once again demonstrates how little we know about biodiversity, these are the 37th and 38th new primate species described since 1990."

June 2002 - A new species of conifer, Xanthocyparis vietnamensis (the golden Vietnamese cypress) discovered in North Vietnam, growing on steep limestone ridges in a mountainous area. What is so special is that they aren't just a new species, but from a hitherto unknown genus. Daniel Harder, director of the University of California at Santa Cruz (UCSC) Arboretum and a co-discoverer of the new species, said "For us to find a previously undescribed large tree like this indicates that there is probably a lot more to be discovered there. It's comparable to the recent discoveries of previously unknown large mammals in Southeast Asia, like the giant muntjac and the saola, a type of ox."

June 2002 - The golden-crowned manakin, a bird of the Amazon rainforest which was presumed to be extinct 45 years ago, has been rediscovered in the Pará region of Brazil where logging and cattle raising on cleared land predominates. "Forest destruction will remain a major threat to the long term survival of this beautiful bird and other wildlife of the area," warned Fábio Olmos who, together with José Fernando Pacheco, rediscovered the bird.

April 2002 - Around 40 environmental campaigners from Greenpeace, disguised as builders, stormed a government building at 22 Whitehall, London. They occupied the building, yards from Downing Street, for three hours, claiming that the government had spent £260,000 on illegal sapele, logged from rainforests in Africa for the doors and windows. Greenpeace claimed that Tony Blair, the British Prime Minister, had broken a promise he made two years ago, when he pledged to source all Government timber from 'legal and sustainable' sources.

April 2002 - At the sixth meeting of the Conference of the Parties to the Convention on Biological Diversity Greenpeace International gave Brazil with the Golden Chainsaw Award for being the biggest impediment to the forest work programme.

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This page last updated: 24 August 2002