IUCN, the International Union for Conservation of Nature

According to the FAO Global Forest Resources Assessment 2000, the net loss in forest area at the global level during the 1990s was an estimated 94 million ha - an area larger than Venezuela and equivalent to 2.4% of the world's total forests. This was a combination of a net annual loss of 12.5 million ha of natural forests and a net annual gain of 3.1 million ha in the form of forest plantations (see table below for details).

However, global statistics tend to obscure significant differences in forest cover change among regions and countries. Net deforestation rates were highest in West Africa and South America. This was followed by Asia, particularly in South-East Asia, though it was significantly offset by forest plantation establishment in other parts of the continent. In contrast, the forest cover in the other regions, largely in industrialized temperate countries, increased slightly primarily as a result of natural forest succession on abandoned agricultural land. The top 10 Losers and Gainers of Forest Cover in 1990-2000 are given in the table below. The countries with the highest net loss of forest area between 1990 and 2000 include Brazil, Indonesia, Sudan, Zambia, Mexico and the Democratic Republic of Congo. Those with the highest net gain of forest area during this period were China, USA, Belarus, Kazakhstan and the Russian Federation. Overall, the world today contains around 6000 square meters of forest for each person, but this is reducing by approximately 12 square meters every year. (FAO, 2001a)

Top 10 Losers and Gainers of Forest Cover in 1990-2000

Along with the physical coverage or quantity of forests, it is equally important to consider the quality of forests. Quantity of forests (i.e. forest area) alone is an inadequate indicator of the health of a forest ecosystem since much of the world's forests are highly fragmented and face considerable human pressure.

Although deforestation is widely recognised as a major conservation challenge, the related issue of habitat fragmentation receives comparatively less attention. As human pressures increase in both temperate and tropical forests, areas that were once continuously forested have become more fragmented. In the Brazilian Amazon alone, the area of forest fragmented or prone to edge effects is 150% greater than the area that has actually been deforested (FAO, 2003). Small fragments have very different ecosystem characteristics from larger areas of forest, containing more light-loving species, more trees with wind- or water-dispersed seeds or fruits, and relatively few under storey species. The smaller fragments also have a greater density of tree falls, a more irregular canopy, more weedy species and unusually abundant vines, lianas and bamboos. Thus, they preserve only a highly biased subset of the original flora and fauna, which is adapted to these conditions.

In a 1997 study, the World Resources Institute coined the term "frontier forests" to describe forested areas that are relatively undisturbed by human activity and are large enough to maintain their original biodiversity, including viable populations of wide-ranging species. According to this study, frontier forests constitute about 40% of total global forest area, but are heavily concentrated in only three large blocks - two areas of boreal forest (in Canada, Alaska, and Russia), and one relatively contiguous area of tropical forest spanning the northwestern Amazon Basin and Guyana Shield (in Brazil, Peru, Venezuela, and Colombia). Additional important outliers can still be found in Central Africa (Congo), and Papua New Guinea. However, nearly 40% of these remaining frontier forests face a moderate to high threat of degradation or clearance.