Forests cover 30 percent of the total land area and include some of the most diverse ecosystems on Earth. The extent of forests is an easily understood baseline variable, which provides a first indication of the relative importance of forests in a country or region. Estimates of change in forest area over time provide an indication of the demand for land for forestry and other land uses, as well as of the impact of significant environmental disasters and disturbances on forest ecosystems. This indicator also serves as a baseline variable in the sense that it directly or indirectly relates to the development of other forest related variables such as the diversity and abundance of species, abundance of species, deforestation, forest fragmentation, area of forest under sustainable management etc.  However, the extent of forest is only one factor in assessing the world’s forests and their contribution to the conservation of biological diversity. It is also vital to present comparable data on the different forest types, to examine forest health and look at the usage and management of these forests. Further, the net loss of forest area is not in itself sufficient to describe land-use dynamics that include both loss of forests due to deforestation and natural disasters and gains in forest area from planting or natural expansion.

The extent of forests, measured as the proportion of land area under forests, is one of the key indicators developed to track progress towards the UN Millennium Development Goal 7. Global assessments of the world’s forests are currently carried out at 5 year intervals by the Food and Agriculture Organization of the United Nations (FAO) where information is collected on this indicator. The latest Global Forest Resources Assessment was completed in 2005 (FRA 2005) and the results of the next assessment is due in 2010. As part of the Global Forest Resources Assessment 2010 (FRA 2010), countries have been asked to provide information of their area of forest (and on the area of other wooded land) for 1990, 2000, 2005 and 2010 (forecast).

The extent of forest types is a sub-category of the indicator “area of forest” used in FRA 2005 and is more challenging given the plethora of different forest type classification systems used by countries. As an example, recent attempts to generate a European forest type classification system resulted in a proposal for 14 categories further subdivided into 76 forest types. Needless to say that most of these would not be relevant to tropical countries.

As part of the Global Forest Resources Assessment 2000 (FRA 2000), FAO generated forest cover maps and maps of global ecological zones as a proxy for broad forest types. An overlay of the two maps generated information on forest area by ecological zone including estimates of the forest area as proportion of each ecological zone by country. Since this initiative was not repeated in FRA 2005, there are currently no trend data available. However, this information will be updated with help of a global remote sensing survey of forests undertaken by FAO and its partners as part of FRA 2010. This survey will provide information on the extent of forests by broad forest types for 1990-2000-2005 using the ecological zone map produced as part of FRA 2000 as the basis.

In addition, countries have been asked to provide data on the area of mangroves, bamboo and rubber plantations and to provide a breakdown of the standing volume of forest into broadleaved and conifers as part of the country-reporting to FRA 2010. 
 

The Ecoregion Protection Indicator can be aggregated into protected area coverage of terrestrial biomes, marine provinces and biogeographic realms, and disaggregated at the regional and national level. The IBA and AZE Protection Indices can also be disaggregated in different ways to reveal underlying patterns in the degree of protection.

Information on the extent of forests is available for most of the countries. The latest assessment (FRA 2005) provided information on the current extent of forest and trends for the period 1990-2000-2005 for 219 countries and territories. However, FRA 2005 also highlighted the large variation in the methodology of estimation, quality of data, year to which the data belongs, availability of data over time and ease with which the data can be verified. Information on forest by ecological zones dates back to year 2000.

Source: FAO, 2006

Source: FAO, 2006
 

Source: FAO, 2006


Source: FAO, 2001
 

The total forest area is just under 4 billion hectares, corresponding to 30 per cent of the total land area or to an average of 0.62 hectares per capita. However, the area of forest is unevenly distributed. For example, 64 countries with a combined population of 2 billion have less than 0.1 ha of forest per capita. The ten most forest-rich countries account for two-thirds of total forest area. Seven countries or areas have no forest at all, and an additional 57 have forest on less than 10 percent of their total land area.

Information on trends in the extent of forest area at national, regional and global scales for the period 1990-2000-2005-2010 will become available in 2010. Preliminary data on the extent of forest by ecological zone are also expected in 2010.

Final results of the global remote sensing survey of forests are expected in 2011.