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( Article Type: Explanation )

The world’s forests, both temperate and tropical, are under enormous pressures from disease (often as a result of air pollution, notably from acid rain), felling for timber needs, clearing for agriculture, or loss under reservoirs through the damming of rivers. According to the Food and Agriculture Organisation of the United Nations (FAO), deforestation was concentrated in the developing world, with a net loss of some 180 million hectares between 1980 and 1995, or an average of 12 million hectares per annum.

The main causes of deforestation are poverty (extension of subsistence farming), overpopulation and ignorance. Sustainable forestry practices involve the re-planting at least as many, if not more, trees than are removed by logging, which offsets at least some of the logging losses.

Deforestation is also harmful to the earth and its inhabitants because trees absorb large amounts of carbon dioxide and, in turn, release oxygen. Consequently, the loss of forests is affecting the earth’s ability to cleanse and freshen the air. Loss of indigenous forests also causes loss of biodiversity of species within the forest ecosystem. A World Resources Institute Study suggests the current loss of natural forests is approximately 160 000 square kilometres per year, an area the size of England and Wales combined.

In addition to the direct effects of logging, disturbing trends have been noted in the quality of forests. A 1995 survey of forest conditions in Europe indicated that over 25% of the trees assessed were suffering from significant defoliation. Annual European surveys showed the numbers of completely healthy trees falling from 69% in 1988 to 39% in 1995.