Deforestation

It has been estimated that an area of tropical rain forest the size of 100 football pitches is destroyed every minute. If this continues the tropical rain forest will have disappeared in about forty years. Forests in more temperate climates are also under threat and you may have read in newspapers about the threat to trees from acid rain. There are many important reasons why we should conserve the forests.

Trees slow down heavy rain before it reaches the soil and their roots help anchor the soil to hillsides. They help to control the amount of moisture in the soil and to maintain its fertility through the rotting of fallen leaves and other fallen vegetation. This natural system of protection fails if the trees are removed.

In every continent of the world soils are being devastated because trees are being cut down, without any regard for the environment, by large timber companies who make huge profits by selling the valuable timber to the richer nations. Some governments encourage the clearing of forests to make more farmland. In many parts of the world local people depend on firewood for fuel for cooking and warmth. They use up trees at an alarming rate and could not afford alternative fuels even if they were available.

You may have seen on television the barren landscape in parts of Africa. Ethiopia is often in the news and when we see that dried-up landscape it is difficult to imagine that only 55 years ago half of Ethiopia was forested. Even fifteen years ago many of the hillsides were covered in trees. Today Ethiopia loses one billion tonnes of soil each year because of wind and water erosion. In Nepal about half the forests have been lost since 1950s and about 20 tonnes of soil are lost from every hectare of treeless mountainside. Soil is thus washed down towards the sea causing rivers to rise and floods to become more and more serious among the villages on the river plains.

In South and Central America farmers have been encouraged to clear the forest to make room for growing crops. This has not been particularly successful as the intensive cropping. After two or three crops have been harvested the soil is no longer fertile and becomes suitable only for rough grazing. From 1966 some 50,000 square kilometres of Brazil’s Amazon jungle were cleared to make way for 336 cattle ranches. The intention was to produce a surplus of beef to export to the USA and Europe. Soon it was realized that the amount of beef produced on this cleared land was a lot less than had been expected, as the forest soils were not as fertile as they had hoped. Only 22 kilogrammes of beef were produced per hectare of land which compares very poorly with 270 kilogrammes per hectare on European farms. Similarly in Nepal, where large areas of trees have been destroyed, yields of rice have gone down by 20 per cent and of maize by 30 per cent.

When we think of forests we often think of them as being useful only for timber and producing very little in the way of food for people. Yet the tropical forests provide food, shelter and medicines for millions of people. They can be for growing crops. In Brazil it has been calculated that an area of untouched forest could produce ten times more food than the beef cattle that graze there. Fruits, nuts, game and fish are the main foods found in the tropical forest. Many of the remote and almost forgotten peoples of the world, like the Baka people of Cameroon, get all they need to survive from the forest, as do the peoples and tribes of the South American rain forest, such as the Yanomami who are completely in tune with their natural surroundings. In Britain we have now forgotten what our ancestors knew about the productivity of our forests: providing timber for houses and ships; fodder for farm animals and game and berries to eat. In medieval times the forests were regulated and farmed so they would remain productive and be conserved for future generations. Perhaps we should be encouraging this kind of ‘forest farming’ in other parts of the world so that the fragile soils will be protected and people fed.