Gorilla Journal 10, June 1995

Dangers for the Tropical Rain Forests

Tropical forests usually grow in places with a minimum precipitation of 100 mm each month in general, a minimum average temperature of 24°C with the temperature never falling below 0°C. Estimates of how many species of animals and plants live in these forests vary widely. Depending on which estimate is used, 24-95% of the 3-100 million extant species occur in the humid forests of the tropics. 44% of the world's endangered mammals and birds live in this habitat.
Free nutrients are rare in this ecosystem. Therefore most trees in the rain forests have shallow roots to be able to absorb any available minerals from decomposing organic matter and rain. Apart from volcanic soils, the fertility of rain forest soils, which consist mostly of sand or latosol, is very low. Once the dense vegetation has been removed, the nutrients are quickly washed out and the thin layer of humus is eroded. After only a few years almost nothing will grow in the impoverished soil. The trees have the additional function of slowing down strong winds, and clouds are formed through the evaporation taking place above forested areas. These clouds bring rain. The quantity of precipitation decreases in large areas once the forests are removed.

Deforestation Continues

According to calculations by FAO, 154,000 km² (0.8%) of forested area was lost annually in the tropics between 1981 and 1990. According to other estimates, this number is even higher. This means that destruction of the tropical forests accelerated considerably through the 1980s, compared to the late 1970s. In 1980, 37% of primary forest had already disappeared in South America, 42% in Asia and 52% in Africa. In the next decade, the annual amount of deforestation still increased by 68%. The speed of forest destruction was highest in West Africa, South East Asia and Central America. By the turn of the millennium, probably all forests have disappeared from Thailand, Myanmar, East Africa, West Africa, Madagascar and the Philippines.

Causes of Forest Destruction

According to David Pearce and Katrina Brown (The causes of Tropical Deforestation), one of the main causes for the destruction of forest is the fact that this ecosystem's actual value for the economy is being dangerously underestimated. The governments of many countries even promote logging of forests with subsidies and tax benefits. In South America, settlers often are forced to clear the forest to keep their land deeds.
More and more arable land is needed because of the high population growth rates. Fallow cycles have already been reduced, and the soil fertility can not recover. According to various estimates, agriculture, especially slash-and-burn cultivation, is responsible for 61-94% of forest loss. It is the main cause of forest destruction in Africa. As the human population continues to grow in the tropics - in Africa at the highest rate - deforestation by smallholders will increase even further.
In Brazil, authorities often regard forested areas as useless land that has to be cleared and made economically profitable. Much of the deforested land is replaced by cattle pasture: in 1989 cattle ranching accounted for 72% of forest destruction in this country. According to Norman Myers, 15,000 km² of tropical rain forest were transformed into pastures in 1989, mainly in Central America and Amazonia.
In Indonesia, an estimated 400,000 km² of forest will be lost by the year 2000. Since 1985, some of the strain has been taken off the most densely populated islands by transmigration of people to islands with low population densities that are still covered with rain forest. There they are given a piece of land to clear and farm. It is planned to move more than one million families in this project, which is funded by the World Bank and developmental aid agencies from various countries.
In South America and Africa, mining of mineral resources is another danger for the forest. In 1989, 10,000 km² of tropical rain forest had to give way to cash-crop plantations, road construction, mining and other activities. Deforestation is advanced considerably by the building of roads, because they make it much easier for the human population to move in and to start clearing the land. According to one estimate, 4-20 km² of rain forest disappear with each kilometer of road in South America. Logging companies are among the most important builders of roads.

Commercial Logging

A company that wants to extract timber in the tropics is given concessions from the government of the respective country. These are clearly defined areas of forest where the company is permitted to work for a certain time. The forestry law regulates which species of trees may be felled, how many and in what way. In 1989, 45,000 km² of rain forest were affected by commercial logging, two thirds of which in Southeast Asia, where it amounted to destruction. Although logging is mainly selective these days (only big logs of certain tree species), the forests are often still considerably damaged in the process. Moreover, even selective logging opens the forests up to continuing exploitation. Between 1981 and 1985, 88% of forests where logging companies had worked previously were destroyed in the Ivory Coast. The figure for Cameroon is 28%, 36% for the Congo, 10% for Gabon, and 42% for Liberia.
In 1990, Malaysia, Indonesia and Brazil were the most important exporting countries for tropical timber. Most kinds of this timber could easily be replaced by others, but they sell well because they are considerably cheaper than timber from the temperate zones.
The International Tropical Timber Organization (ITTO) emphasizes in its guidelines that the exploitation of tropical forests is only justified if various rules are followed, one of them being sustainability. In forestry terms this usually means that some kind of forest will be kept after logging, and a change in species composition (generally a loss of diversity) is accepted as a consequence. However, in ecological terms sustainability requires that the removed species of trees should regenerate in this area.
There is hardly any evidence for any area, in tropical Africa or elsewhere, that ecologically sustainable use of the common tropical timber tree species is possible with selective logging as it is employed today. Most evidence suggests that the respective tree species may not grow back to harvestable size over the envisaged logging cycles. ITTO itself reports that currently less than 1% of tropical timber on the world market originates in sustainable use areas. It may be doubted whether the organization's goal of marketing only such timber by the year 2000 is a realistic one.

Rain Forests in Africa

Compared to Asian and American rain forests, the biodiversity of those in tropical Africa is rather low. During the Ice Ages these forests were reduced to small areas in western and eastern equatorial Africa by a decrease in temperature and humidity. About 10,000 years ago these forest remnants expanded again and formed a continuous area which has decreased again for the last 8,000 years. According to estimates by FAO, in 1990 168,630 km² of tropical Africa was covered by a closed forest; this is equivalent to 22.6% of tropical Africa's total area.
The West African forests have suffered the worst damage, because they were ruthlessly logged in the past. Logging companies have been playing an important role in this since the 1950s. In 1980, when only an estimated 26.5% of the original forested area still existed in West Africa, 4.8 million m3 of timber were extracted in the Ivory Coast and 5.1 million m³ in Nigeria, compared to less than 2 million m³ in Cameroon and Gabon. In 1980, 5.2% of remaining rain forest was destroyed in the Ivory Coast (20% by commercial logging); by 1990 the forest cover was so badly reduced that only 2.1 million m³ of timber could be extracted. In Nigeria, the annual harvest stayed consistently at 5.6 million m³ during the 1980s.
In 1989, the Ivory Coast and Nigeria had the highest rate of deforestation of all tropical countries with 15.6% and 14.3%, respectively. Thailand and Madagascar were next with 8.1% and 8.3%, respectively. By now, probably 80% of rain forests have been destroyed in the Ivory Coast and about 90% in Nigeria.

The Value of Rain Forests to Humanity

The most sought after product of tropical rain forests is timber, but numerous alternative forest products are also exploited. These include rubber, rattan, bamboo, camphor, resins, tannins, essential oils, dyes, plant fibres, fruit, nuts, spices, medicinal plants, insects and bush meat. Many people living in the forests and their surroundings are earning a living from these forest products. The industrialized countries are also becoming increasingly aware of the value of these resources.
To many groups, there is only one argument in favour of the conservation of rain forests: the economic value of these ecosystems. In order to provide arguments for their conservation, many attempts have been made to calculate this economic value and to compare it with the profit that can be gained by logging and deforestation. According to such a study in Korup National Park, Cameroon, the direct value of the forest (sustainable use, tourism, water resources) is 3.6 times higher than the value of the timber. In Peru, another author found that the market value of sustainably used alternative forest products was more than twice the profit from timber plantations or cattle ranching on a comparable area, and more than six times the value of the timber that could have been harvested if the area had been cleared. In several studies in other South American countries, the same was found: the use of alternative forest products yields a higher profit than logging, agriculture or cattle ranching.
It becomes increasingly obvious that the indirect value of rain forests has to be taken into consideration in addition to their direct value to arrive at a proper estimate of their importance. This is especially true for the ecological and climatic consequences of the clearing of large areas. Thus the economist David Pearce estimates the increase in the greenhouse effect caused by the quantity of carbon dioxide that is produced by the burning of 1 ha of rain forest will cause costs that are equivalent to US$ 1,300 per year.
In the 1980s, 22-26% of the greenhouse gas emissions was produced through the destruction of tropical forests. As global climate changes concern the industrialized countries as well, it is in their own interest to contribute to the conservation of rain forests.

The World Bank

One of the international organizations that have the most influence on the future of the rain forests is the World Bank. In many cases, it pushed ahead the destruction of large areas of rain forest through grants for projects that were ecologically questionable, such as dams. The introduction of structural adjustment programs in 1979 has also been dangerous for rain forests in some cases. Within these programs, grants are only awarded if the recipient countries reorientate their economies. This means also the improvement of the economic climate and the capacity to attract foreign investors, reduction of government deficits through spending cuts (for example for education and medical care) as well as an increase in foreign exchange earnings by the promotion of exports. In order to increase exports, forests often have to be cleared or exploited more heavily.
As a reaction to increasing criticism the World Bank set up the Global Environment Facility (GEF) in 1991, which is intended to fund measures towards the conservation of the environment and of natural resources as well as the introduction of environmentally friendly technologies. UN organizations support GEF, too. GEF gives grants which do not have to be redeemed by the recipient countries. For example, GEF funds support rain forest biodiversity projects in Zaire, Uganda (Bwindi), the Congo, the Central African Republic and Cameroon.

Tropical Forest Action Program

UNDP and FAO, both UN organizations, developed the Tropical Forest Action Program (TFAP) in 1985 as an international effort to the conservation of tropical rain forests. Within this program, the countries that have tropical rain forest are supposed to develop national action plans as to how these forests can be used in a sustainable way. To realize these programs, they are supported technically and financially. The main aim is the development of forestry. In Cameroon, for example, considerable expansion of logging was identified as a means to increase foreign exchange earnings through the export of timber products. Even areas inhabited by pygmies were supposed to be exploited, although the consideration of indigenous peoples' needs was one of TFPA's expressed aims. In 1990, evidence was published to prove that TFAP promoted deforestation rather than prevented it. Subsequently, FAO ordered an investigation. Today, the TFAP emphasizes the following goals: education of the population about the dangers of forest destruction, planning of more effective strategies and activities, and raising of national and international funds to put these plans into practice. National programs have already been implemented in numerous African countries. In most cases they are supported by UNDP, FAO and the World Bank; in Zaire, Canadian developmental aid supports the TFAP.
A national action plan has been working in the Congo since 1994. However, the local population and the responsible authorities were not involved in the planning stage. Other points of criticism are that the TFAP represents rather the interests of foreign investors than those of the Congo and that it does not offer a solution for the threats to the Congolese forests.
The TFAP still has many weaknesses and will have to be improved considerably before it can make an effective contribution to the conservation of rain forests. In any case, the cooperation of all organizations working towards this goal is necessary.

Angela Meder

Dr. Angela Meder observed the behaviour and development of captive lowland gorillas for 10 years. A major aim of her various studies was the improvement of the management, rearing and housing of gorillas in zoos. Today she works as a book editor. Since 1992 she has been part of the Board of Directors of Berggorilla & Regenwald Direkthilfe.

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