Much of the land currently in production is subject to erosion, especially during prolonged droughts. 2 Forests Forests have been described as the hearts and lungs of the world. Their heart-land description arises from the fact that most river systems originate in the forest. Forests prevent soil erosion, maintain high water quality, and regulate the flow of water in different seasons, thus providing the bloodstream of agriculture, industry and human communities. This is an important element in the global carbon reservoir.
Forests also filter particulate pollution from the air, and improve local and regional climates.
Fundamentally, the forest acts as a sponge or a protective cover which stops rain from falling directly on bare land, and thereby causing excessive erosion. Particularly in the tropics, forests are a major source of global genetic diversity. Tragically, the world is facing serious declines in forest cover. In a recent report, FAO found that annual tropical deforestation had increased from 9 million hectares in 1980 to 16.8 million in 1990. As population continues to expand, all the world's forests are threatened.