Before the dawn of agriculture, some 10,000 years ago, the Earth boasted a rich mantle of forest and open woodland covering some 6,200 million hectares. Over the centuries, a combination of land clearing for crop production, commercial timber harvesting, cattle ranching and fuelwood gathering has shrunk the Earth's forests to some 4,200 million hectares-a third less than existed in preagricultural times.
For centuries, this reduction in the Earth's biological stock hindered human progress little, if at all. indeed, the clearing of trees to expand food production and the harvesting of forest products were vital aspects of economic and social development. But the relentless loss of tree cover has recently begun to impinge on the economic and environmental health of numerous nations, mostly in the developing world. Largescale reforestation, combined with concerted efforts to protect remaining forests, now appears essential to Improving the human prospect.
Most tree planting efforts over the last several decades have aimed at increasing supplies of marketable timber, pulp and fuelwood for cities-forest products that yield obvious economic benefit. By contrast, reforestation for reasons that lie outside the monetized economy has been vastly under-attended, Yet trees quite literally form the roots of many natural systems. With the inexorable march of deforestation,the ecological integrity of many areas is disintegrating-causing severe soil loss aggravating droughts and floods, disrupting water supplies and reducing land productivity.
Trees are also a vital component of the survival economy of the rural poor Hundreds of millions of people rely on gathered wood to cook their meals and heat their homes. For them, lack of access to wood translates into reduced living standards and, in some cases, directly into malnutrition. In addition, trees and soils play a crucial role in the global cycling of carbon, the importance of which has been magnified by the emergence of carbon dioxide-induced climate change as arguably the most threatening environmental problem of modern times.
Efforts to slow deforestation certainly deserve redoubled support. But even if forest clearing miraculously ceased today, millions of hectares of trees would still have to be planted to meet future fuelwood needs and to stabilize soil and water resources. Increased planting to satisfy rising demands for paper, lumber and other industrial wood products is also crucial. Expanding forest cover for all these reasons will reduce pressures on remaining virgin forest, helping thereby to safeguard the Earth's biological diversity. At the same time it will mitigate the build-up of atmospheric carbon dioxide, which gives industrial countries sound reason to step up support for tree planting in developing countries.
Successfully reforesting large areas of degraded lands, however, will require much more than financial commitments from governments and international lending agencies. It will take a shift in emphasis from government foresters establishing and maintaining commercial plantations to the much more complex tasks of starting nurseries in thousands of villages and encouraging the planting of multi-purpose trees along roads, on farms and around houses. Only by garnering the knowledge, support and human energy of rural people themselves-and planting to meet their basic needs-is there any hope of success.
Dramatic changes in regional forest cover historically reflect powerful societal transformations. Beginning in the sixteenth century, the expanding agricultural and industrial needs of Renaissance societies spurred the clearing of large tracts of forest in Western Europe. France, once 80 per cent forested, had trees covering only 14 per cent of its territory by 1789. Both the French and the English so depleted their domestic forest resources that they were forced, by the mid-seventeenth century, to conduct a worldwide search for ship timbers in order to maintain their maritime superiority. …