Global overview

The unique nature of forest ecosystems has long been acknowledged. Forest ecosystems play multiple roles at global as well as local levels: as providers of environmental services to nature in general - and humans in particular - and as sources of economically valued products (see box). The 1972 Stockholm Conference recognized forests as the largest, most complex and self-perpetuating of all ecosystems, and emphasized the need for sound land and forest use policies, ongoing monitoring of the state of the world's forests and the introduction of forest management planning. It was recommended that countries should:

• strengthen basic and applied research for improved forest planning and management, with emphasis on environmental functions of forests; and
• modernize forest management concepts by including multiple functions and reflecting the cost and benefits of the amenities that forests provide.

The Conference also called for:

• cooperation of United Nations bodies to meet the needs for new knowledge to incorporate environmental values in national land use and forest management; and
• continuing surveillance of the world's forest cover through the establishment (in countries) of an appropriate monitoring system.

Forest cover 2000

Forest covered some 3 866 million ha of the planet in the year 2000 - somewhat less than one-third of total land area Note: dark green represents closed forest, more than 40 per cent covered with trees more than 5 metres high; mid-green represents open (10-40 per cent coverage) and fragmented forest; light green represents other woodland, shrubland and bushland Source: FAO 2001b

Today, the Stockholm Conference recommendations relating to forests remain valid and unfulfilled, in many ways, because of conflicting interests in managing forests for environmental conservation and economic development.

Deforestation over the past 30 years has been the continuation of a process with a long history. By the time of the Stockholm Conference, much of the Earth's forest cover had already been cleared. The historic loss of forests is closely related to demographic expansion and the conversion of forest land to other uses. Major direct causes of forest degradation brought on by humans include overharvesting of industrial wood, fuelwood and other forest products, and overgrazing. Underlying causes include poverty, population growth, markets and trade in forest products, and macroeconomic policies. Forests are also susceptible to natural factors such as insect pests, diseases, fire and extreme climatic events.

A number of assessments of changes in forest cover have been carried out over the past 30 years including FAO and UNEP 1982, FAO 1995, FAO 1997, FAO 2001b, UNEP 2001 and WRI 1997). While differing in their definitions of forest cover, methodology and specific results, making detailed comparisons unreliable, these assessments have reinforced each other in their overall depiction of declining forest areas and continued degradation of forest ecosystems.

The 1980 Tropical Forest Resources Assessment by FAO and UNEP was the first comprehensive assessment of tropical forests. Th e rate of tropical deforestation was calculated at 11.3 million ha a year FAO and UNEP 1982), vindicating the fears of the Stockholm Conference about the alarming rate of global forest loss. Since then, while forest area in developed countries has stabilized and is slightly increasing overall, deforestation has continued in developing countries (FAO-ECE 2000, FAO 2001b, FAO 2001a).

Causes of forest area change (percentage of total) by region

In the 1990s, almost 70 per cent of deforested areas were changed to agricultural land. In Latin America, most conversion was large scale, whereas in Africa small-scale agricultural enterprises predominated Notes: 'pan-tropical' refers to data samples from satellite images of tropical areas; regions do not correspond exactly to GEO regions Source: FAO 2001b

FAO's Global Forest Resources Assessment 2000 (FAO 2001b), using for the first time a common definition of forests as areas of at least 0.5 ha with tree crown cover of more that 10 per cent, concluded that:

• The total area covered by forest is approximately 3 866 million ha, almost one-third of the world's land area, of which 95 per cent is natural forest and 5 per cent is planted forest; 17 per cent is in Africa, 19 per cent in Asia and the Pacific, 27 per cent in Europe, 12 per cent in North America and 25 per cent in Latin America and the Caribbean (see table below). About 47 per cent of forests worldwide are tropical, 9 per cent subtropical, 11 per cent temperate and 33 per cent boreal.
• At the global level, the net loss in forest area during the 1990s was an estimated 9.4 million ha (equivalent to 2.4 per cent of total forests). This was the combined effect of a deforestation rate of 14.6 million ha per year and a rate of forest increase of 5.2 million ha per year. Deforestation of tropical forests is almost 1 per cent per year.
• The area under forest plantations grew by an average of 3.1 million ha per year during the 1990s. Half of this increase was the result of afforestation on land previously under non-forest land use, whereas the other half resulted from conversion of natural forest.
• The world's natural forests have continued to be converted to other land uses at a very high rate. During the 1990s, the total loss of natural forests (deforestation plus the conversion of natural forests to forest plantations) was 16.1 million ha per year, of which 15.2 million ha occurred in the tropics.
• In the 1990s, almost 70 per cent of deforested areas were changed to agricultural land, predominantly under permanent rather than shifting systems. In Latin America most conversion was large scale, whereas in Africa small-scale agricultural enterprises predominated. Changes in Asia were more equally distributed between permanent large- and small-scale agriculture and areas under shifting cultivation.

A recent study using globally comprehensive and consistent satellite data estimated that the extent of the world's remaining closed natural forests (where crown cover is more than 40 per cent) in 1995 was 2 870 million ha, about 21.4 per cent of the land area of the world (UNEP 2001). About 81 per cent of these forests are concentrated in just 15 countries. Ranked in the highest to lowest order these are: the Russian Federation, Canada, Brazil, the United States, Democratic Republic of the Congo, China, Indonesia, Mexico, Peru, Colombia, Bolivia, Venezuela, India, Australia and Papua New Guinea. The first three countries contain about 49 per cent of the remaining closed forests. More than a quarter of closed forests grow on mountains (see box).

Change in forested land 1990-2000 by region
	total land area (million ha)	total forest 1990 (million ha)	total forest 2000 (million ha)	% of land forested in 2000	change 1990-2000 (million ha)	% change per year
Africa	2 963.3	702.5	649.9	21.9	-52.6	-0.7
Asia and the Pacific	3 463.2	734.0	726.3	21.0	-7.7	-0.1
Europe	2 359.4	1 042.0	1 051.3	44.6	9.3	0.1
Latin America and the Caribbean	2 017.8	1 011.0	964.4	47.8	-46.7	-0.5
North America	1 838.0	466.7	470.1	25.6	3.9	0.1
West Asia	372.4	3.6	3.7	1.0	0.0	0.0
world	13 014.1	3 960.0	3 866.1	29.7	-93.9	-0.24
Source: compiled from FAO 2001b Note: numbers may not add due to rounding