Forest cover in general refers to the relative (in percent) or sure (in square kilometres/square miles) land area that is covered by forests.
According to the Food and Agriculture Organization, a forest is defined as land spanning more than 0.5 hectares with trees higher than 5 meters and a canopy cover of more than 10 percent, or trees able to reach these thresholds in situ. It does not include land that is predominantly under agricultural or urban land use.
Forest cover is one category of terrestrial land cover. Land cover is the observed physical features, both natural and manmade, that occupy the earth’s immediate surface … forest cover is defined as 25% or greater canopy closure at the Landsat pixel scale (30-m × 30-m spatial resolution) for trees >5 m in height
— Hansen et al., 2010
Global forest cover, however crucial for soil health, the water cycle, climate and air quality it is, is severely threatened by deforestation, as a direct consequence of agriculture, grazing, and mining. Forest cover can be increased by reforestation and afforestation efforts, but it is very virtually impossible to restore the full range of ecological services once natural forests are converted to other land uses.
Since the onset of agriculture (about 12,000 years ago), the number of trees worldwide has dropped by 46%, according to one research published in 2018.
Global forest cover now has been estimated to be just 31% or 40 million square kilometres (4.3×1014 sq ft) in 2006 with 12-yearly losses (2000-2012) amounting to 2.3 million square kilometres (2.5×1013 sq ft) and reforestation gains about 0.8 million square kilometres (8.6×1012 sq ft). According to FAO’s Global Forest Resources Assessment 2020, the world has a total forest area of 4.06 billion hectares (ha), which is 31 percent of the total land area.
More than half of the world’s forests are found in only five countries (Brazil, Canada, China, Russian Federation and United States of America).
The largest part of the forest (45 percent) is found in the tropical domain, followed by the boreal, temperate and subtropical domains. These domains are further divided into terrestrial global ecological zones, 20 of which contain some forest cover. Almost half the forest area (49 percent) is relatively intact, while 9 percent is found in fragments with little or no connectivity. Tropical rainforests and boreal coniferous forests are the least fragmented, whereas subtropical dry forest and temperate oceanic forests are among the most fragmented. Roughly 80 percent of the world’s forest area is found in patches larger than 1 million hectares. The remaining 20 percent is located in more than 34 million patches across the world – the vast majority less than 1 000 hectares in size.
The world’s total growing stock of trees decreased slightly, from 560 billion m3 in 1990 to 557 billion m3 in 2020, due to a net decrease in forest area. On the other hand, growing stock is increasing per unit area globally and in all regions; it rose from 132 m3 per ha in 1990 to 137 m3 per ha in 2020. Growing stock per unit area is highest in the tropical forests of South and Central America and West and Central Africa.
In particular, forest cover may refer to
- Forest cover by state in the United States
- Forest cover by state or territory in Australia
- Forest cover by province or territory in Canada
- Forest cover by state in India
- Forest cover by federal subject in Russia
More than half (54%) of the world’s forests is in only five countries – the Russian Federation, Brazil, Canada, the United States of America and China.