Forests

The global area of forest of all kinds was about 8.4 billion acres (3.4 billion hectares) in 1990, of which 4.3 billion acres (1.76 billion ha) was tropical forest and the rest temperate and boreal forest. That global forest area is at least one-third smaller than it was prior to extensive deforestation caused by human activities. Most of the deforested land has been converted to permanent agricultural use, but some has been ecologically degraded into semi-desert or desert. This global deforestation, which is continuing apace, is one of the most serious aspects of the environmental crisis.

Forests are an extremely important natural resource that can potentially be sustainably harvested and managed to yield a diversity of commodities of economic importance. Wood is by far the most important product harvested from forests. The wood is commonly manufactured into paper, lumber, plywood, and other products. In addition, in most of the forested regions of the less-developed world firewood is the most important source of energy used for cooking and other purposes. Potentially, all of these forest products can be sustainably harvested. Unfortunately, in most cases forests have been unsustainably overharvested, resulting in the "mining" of the forest resource and widespread ecological degradation. It is critical that in the future all forest harvesting is conducted in a manner that is more responsible in terms of sustaining the resource.

Many other plant products can also be collected from forests, such as fruits, nuts, mushrooms, and latex for manufacturing rubber. In addition, many species of animals are hunted in forests, for recreation or for subsistence. Forests provide additional goods and services that are important to both human welfare and to ecological integrity, including the control of erosion and water flows, and the cleansing of air and water of pollutants. These are all important forest values, although their importance is not necessarily assessed in terms of dollars. Moreover, many of these values are provided especially well by old-growth forests, which in general are not very compatible with industrial forestry practices. This is one of the reasons why the conservation of old-growth forest is such a controversial topic in many regions of North America and elsewhere. In any event, it is clear that when forests are lost or degraded, so are these important goods and services that they can provide.