Indicators of Forest Extent

Forest Gain

Last Updated on September 6, 2024

This indicator aims to monitor the total land area that has transitioned from an unforested to a forested state in a given period of time. The indicator currently measures tree cover gain as a best-available proxy for forest gain. Tree cover gain includes natural regeneration and gain from restoration interventions, as well as gain from planted forests and tree crops, which are not typically considered forests. Areas of tree cover gain were derived by comparing the difference between tree cover extent maps for 2000 and 2020. The statistics reported in this indicator capture “gross” tree cover gain, which is the total gain separate from the tree cover loss that occurred.

 

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How much tree cover gain occurred globally between 2000 and 2020?

The world experienced 130.9 million hectares (Mha) of tree cover gain between 2000 and 2020  — an area roughly the size of Peru. Currently, this figure includes areas that may have experienced gain resulting from natural regeneration and restoration interventions, as well as from tree plantations. While trends over time for different types of tree cover cannot yet be assessed annually because the current data set only compares baseline (2000) and end point (2020) conditions, annual time series data are under development and may allow for better distinctions between reforestation, natural regrowth of degraded forest, and harvesting/regrowth rotations of plantations and production forests.

While the world experienced 130.9 Mha of gross tree cover gain, it actually lost more tree cover than it gained due to tree cover loss during the same time period. See below for more information on net tree cover change.

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Areas of gross tree cover gain between 2000 and 2020

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How is tree cover gain distributed throughout the world?

Approximately 59 percent of the 130.9 Mha of global tree cover gain between 2000 and 2020 occurred in temperate and boreal forests, while the remaining 41 percent occurred in tropical and subtropical forests.  Tree cover gain in Russia and Canada comprised the vast majority of total gain in boreal and temperate climate domains, at 49 percent and 22 percent respectively, predominantly from the regeneration of production forests and regrowth of trees on abandoned agricultural land. About half of the total gain in tropical and subtropical climate domains occurred in Brazil, the United States, Indonesia, China, Thailand and India. 

When also considering tree cover loss between 2000 and 2020, only temperate forests experienced a net gain in tree cover. See below for more information on net tree cover change.

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Global tree cover gain by climate domain between 2000 and 2020

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How much tree cover gain occurred in plantations?

Of the 130.9 Mha gain in tree cover between 2000 and 2020, an estimated 14 percent (19 Mha) comprises planted trees that are managed specifically to provide commercial tree-based products like pulp, timber, oil palm, rubber and fruit.  This estimate is based on an aggregate map of planted trees that accounts for approximately 90 percent of planted forests worldwide.  By proxy, the remaining 86 percent of gain (111.9 Mha) is estimated to be “natural” forest gain, which is comprised of gain from natural regeneration or human-assisted restoration. 

Two countries, Indonesia and Brazil, accounted for nearly one third of the world’s 19 Mha of tree cover gain due to plantations from 2000 to 2020.  In Indonesia, oil palm is the dominant type of plantation, while in Brazil, timber plantations of eucalyptus, pine and other fast-growing species for pulpwood and building materials dominate, particularly in the southeastern region of the country. 

In Malaysia, Uruguay and New Zealand, at least 70 percent of each country’s tree cover gain occurred inside plantations.  (See Production Forests Indicator.)

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How did tree cover gain compare to loss between 2000 and 2020?

Even though the world gained 130.9 Mha of tree cover between 2000 and 2020, it still lost much more, with an overall net loss of 100.6 Mha. While the global numbers report a negative trajectory, there are distinct regional patterns or “hotspots” of net gain. At least 36 countries gained more tree cover than they lost over the 20-year time period.  As a continent, Europe gained 6 million hectares of tree cover by 2020. Asia also had a large proportion of countries with net gain, particularly in Central and South Asia. The drivers of much of this gain (for example, what proportion is due to intentional restoration interventions versus land abandonment) are still difficult to determine using the available data, but are a key area for future research. Additionally, even though tree cover gain is occurring in many places, it doesn’t “cancel out” the impacts of loss. Primary forests in particular serve as critical carbon stores and support an intricate network of wildlife, none of which can easily be replaced once lost.

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36 countries gained more trees than they lost between 2000 and 2020

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Limitations and Future Prospects

 

Unlike forest loss, which generally occurs swiftly, forest gain is a gradual process that takes years to occur. Forest gain is therefore difficult to detect from satellite imagery over short intervals, and the reported accuracy of the global tree cover gain data set is about 71 percent (compared to 88 percent for loss). 

Most statistics reported in this indicator capture “gross” tree cover gain, which is the total gain separate from the tree cover loss that occurred. (The section How did tree cover gain compare to loss between 2000 and 2020? accounts for both loss and gain for net change.)

Gain includes areas of tree cover that were less than five meters in 2000 and greater than or equal to five meters in 2020. Areas of tree cover that were lost before 2000 and regained sometime within the 20-year period may also be captured as gain. However, since the data only shows gain between two points in time, some changes that occurred during that time may not be captured. For example, trees that were present in 2000 but were cut and grew back to a similar height by 2020 are not captured as gain in this indicator. Forthcoming annual data will help to identify trends throughout the time series, as well as rotational and shorter-term forest dynamics.

Tree cover gain is not the same as restoration. Learn more on the Key Terms and Definitions page.

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Dark surfaces absorb the rays from the sun (low albedo).\r\n"},"94":{"name":"biodiversity intactness","description":"The proportion and abundance of a location\u0027s original forest community (number of species and individuals) that remain.\u0026nbsp;\r\n"},"95":{"name":"biodiversity significance","description":"The importance of an area for the persistence of forest-dependent species based on range rarity.\r\n"},"142":{"name":"boundary plantings","description":"Trees planted along boundaries or property lines to mark them well.\r\n"},"98":{"name":"carbon dioxide equivalent (CO2e)","description":"Carbon dioxide equivalent (CO2e) is a measure used to aggregate emissions from various greenhouse gases (GHGs) on the basis of their 100-year global warming potentials by equating non-CO2 GHGs to the equivalent amount of CO2.\r\n"},"99":{"name":"CO2e","description":"Carbon dioxide equivalent (CO2e) is a measure used to aggregate emissions from various greenhouse gases (GHGs) on the basis of their 100-year global warming potentials by equating non-CO2 GHGs to the equivalent amount of CO2.\r\n"},"1":{"name":"deforestation","description":"The change from forest to another land cover or land use, such as forest to plantation or forest to urban area.\r\n"},"77":{"name":"deforested","description":"The change from forest to another land cover or land use, such as forest to plantation or forest to urban area.\r\n"},"76":{"name":"degradation","description":"The reduction in a forest\u2019s ability to perform ecosystem services, such as carbon storage and water regulation, due to natural and anthropogenic changes.\r\n"},"75":{"name":"degraded","description":"The reduction in a forest\u2019s ability to perform ecosystem services, such as carbon storage and water regulation, due to natural and anthropogenic changes.\r\n"},"79":{"name":"disturbances","description":"A discrete event that changes the structure of a forest ecosystem.\r\n"},"68":{"name":"disturbed","description":"A discrete event that changes the structure of a forest ecosystem.\r\n"},"65":{"name":"driver of tree cover loss","description":"The direct cause of forest disturbance.\r\n"},"70":{"name":"drivers of loss","description":"The direct cause of forest disturbance.\r\n"},"81":{"name":"drivers of tree cover loss","description":"The direct cause of forest disturbance.\r\n"},"102":{"name":"evapotranspiration","description":"When solar energy hitting a forest converts liquid water into water vapor (carrying energy as latent heat) through evaporation and transpiration.\r\n"},"2":{"name":"forest","description":"Forests include tree cover greater than 30 percent tree canopy density and greater than 5 meters in height as mapped at a 30-meter Landsat pixel scale.\r\n"},"3":{"name":"forest concession","description":"A legal agreement allowing an entity the right to manage a public forest for production purposes.\r\n"},"90":{"name":"forest concessions","description":"A legal agreement allowing an entity the right to manage a public forest for production purposes.\r\n"},"53":{"name":"forest degradation","description":"The reduction in a forest\u2019s ability to perform ecosystem services, such as carbon storage and water regulation, due to natural and anthropogenic changes.\r\n"},"54":{"name":"forest disturbance","description":"A discrete event that changes the structure of a forest ecosystem.\r\n"},"100":{"name":"forest disturbances","description":"A discrete event that changes the structure of a forest ecosystem.\r\n"},"5":{"name":"forest fragmentation","description":"The breaking of large, contiguous forests into smaller pieces, with other land cover types interspersed.\r\n"},"6":{"name":"forest management plan","description":"A plan that documents the stewardship and use of forests and other wooded land to meet environmental, economic, social, and cultural objectives. Such plans are typically implemented by companies in forest concessions.\r\n"},"62":{"name":"forests","description":"Forests include tree cover greater than 30 percent tree canopy density and greater than 5 meters in height as mapped at a 30-meter Landsat pixel scale.\r\n"},"69":{"name":"fragmentation","description":"The breaking of large, contiguous forests into smaller pieces, with other land cover types interspersed.\r\n"},"80":{"name":"fragmented","description":"The breaking of large, contiguous forests into smaller pieces, with other land cover types interspersed.\r\n"},"74":{"name":"gain","description":"The establishment of tree canopy in an area that previously had no tree cover. Tree cover gain may indicate a number of potential activities, including natural forest growth or the crop rotation cycle of tree plantations.\r\n"},"143":{"name":"global land squeeze","description":"Pressure on finite land resources to produce food, feed and fuel for a growing human population while also sustaining biodiversity and providing ecosystem services.\r\n"},"7":{"name":"hectare","description":"One hectare equals 100 square meters, 2.47 acres, or 0.01 square kilometers and is about the size of a rugby field. A football pitch is slightly smaller than a hectare (pitches are between 0.62 and 0.82 hectares).\r\n"},"66":{"name":"hectares","description":"One hectare equals 100 square meters, 2.47 acres, or 0.01 square kilometers and is about the size of a rugby field. A football pitch is slightly smaller than a hectare (pitches are between 0.62 and 0.82 hectares).\r\n"},"67":{"name":"intact","description":"A forest that contains no signs of human activity or habitat fragmentation as determined by remote sensing images and is large enough to maintain all native biological biodiversity.\r\n"},"78":{"name":"intact forest","description":"A forest that contains no signs of human activity or habitat fragmentation as determined by remote sensing images and is large enough to maintain all native biological biodiversity.\r\n"},"8":{"name":"intact forests","description":"A forest that contains no signs of human activity or habitat fragmentation as determined by remote sensing images and is large enough to maintain all native biological biodiversity.\r\n"},"55":{"name":"land and environmental defenders","description":"People who peacefully promote and protect rights related to land and\/or the environment.\r\n"},"9":{"name":"loss driver","description":"The direct cause of forest disturbance.\r\n"},"10":{"name":"low tree canopy density","description":"Less than 30 percent tree canopy density.\r\n"},"84":{"name":"managed forest concession","description":"Areas where governments have given rights to private companies to harvest timber and other wood products from natural forests on public lands.\r\n"},"83":{"name":"managed forest concession maps for nine countries","description":"Cameroon, Canada, Central African Republic, Democratic Republic of the Congo, Equatorial Guinea, Gabon, Indonesia, Liberia, and the Republic of the Congo\r\n"},"104":{"name":"managed natural forests","description":"Naturally regenerated forests with signs of management, including logging, clear cuts, etc.\r\n"},"91":{"name":"megacities","description":"A city with more than 10 million people.\r\n"},"57":{"name":"megacity","description":"A city with more than 10 million people."},"56":{"name":"mosaic restoration","description":"Restoration that integrates trees into mixed-use landscapes, such as agricultural lands and settlements, where trees can support people through improved water quality, increased soil fertility, and other ecosystem services. This type of restoration is more likely in deforested or degraded forest landscapes with moderate population density (10\u2013100 people per square kilometer). "},"86":{"name":"natural","description":"A forest that is grown without human intervention.\r\n"},"12":{"name":"natural forest","description":"A forest that is grown without human intervention.\r\n"},"63":{"name":"natural forests","description":"A forest that is grown without human intervention.\r\n"},"144":{"name":"open canopy systems","description":"Individual tree crowns that do not overlap to form a continuous canopy layer.\r\n"},"82":{"name":"persistent gain","description":"Forests that have experienced one gain event from 2001 to 2016.\r\n"},"13":{"name":"persistent loss and gain","description":"Forests that have experienced one loss or one gain event from 2001 to 2016."},"97":{"name":"plantation","description":"An area in which trees have been planted, generally for commercial purposes.\u0026nbsp;\r\n"},"93":{"name":"plantations","description":"An area in which trees have been planted, generally for commercial purposes.\u0026nbsp;\r\n"},"88":{"name":"planted","description":"A forest composed of trees that have been deliberately planted and\/or seeded by humans.\r\n"},"14":{"name":"planted forest","description":"Stand of planted trees \u2014 other than tree crops \u2014 grown for wood and wood fiber production or for ecosystem protection against wind and\/or soil erosion.\r\n"},"73":{"name":"planted forests","description":"Stand of planted trees \u2014 other than tree crops \u2014 grown for wood and wood fiber production or for ecosystem protection against wind and\/or soil erosion."},"148":{"name":"planted trees","description":"Stand of trees established through planting, including both planted forest and tree crops."},"149":{"name":"Planted trees","description":"Stand of trees established through planting, including both planted forest and tree crops."},"15":{"name":"primary forest","description":"Old-growth forests that are typically high in carbon stock and rich in biodiversity. The GFR uses a humid tropical primary rainforest data set, representing forests in the humid tropics that have not been cleared in recent years.\r\n"},"64":{"name":"primary forests","description":"Old-growth forests that are typically high in carbon stock and rich in biodiversity. The GFR uses a humid tropical primary rainforest data set, representing forests in the humid tropics that have not been cleared in recent years.\r\n"},"58":{"name":"production forest","description":"A forest where the primary management objective is to produce timber, pulp, fuelwood, and\/or nonwood forest products."},"89":{"name":"production forests","description":"A forest where the primary management objective is to produce timber, pulp, fuelwood, and\/or nonwood forest products.\r\n"},"87":{"name":"seminatural","description":"A managed forest modified by humans, which can have a different species composition from surrounding natural forests.\r\n"},"59":{"name":"seminatural forests","description":"A managed forest modified by humans, which can have a different species composition from surrounding natural forests. "},"96":{"name":"shifting agriculture","description":"Temporary loss or permanent deforestation due to small- and medium-scale agriculture.\r\n"},"103":{"name":"surface roughness","description":"Surface roughness of forests creates\u0026nbsp;turbulence that slows near-surface winds and cools the land as it lifts heat from low-albedo leaves and moisture from evapotranspiration high into the atmosphere and slows otherwise-drying winds. \r\n"},"17":{"name":"tree cover","description":"All vegetation greater than five meters in height and may take the form of natural forests or plantations across a range of canopy densities. Unless otherwise specified, the GFR uses greater than 30 percent tree canopy density for calculations.\r\n"},"71":{"name":"tree cover canopy density is low","description":"Less than 30 percent tree canopy density.\r\n"},"60":{"name":"tree cover gain","description":"The establishment of tree canopy in an area that previously had no tree cover. Tree cover gain may indicate a number of potential activities, including natural forest growth or the crop rotation cycle of tree plantations.\u0026nbsp;As such, tree cover gain does not equate to restoration.\r\n"},"18":{"name":"tree cover loss","description":"The removal or mortality of tree cover, which can be due to a variety of factors, including mechanical harvesting, fire, disease, or storm damage. As such, loss does not equate to deforestation.\r\n"},"150":{"name":"tree crops","description":"Stand of perennial trees that produce agricultural products, such as rubber, oil palm, coffee, coconut, cocoa and orchards."},"19":{"name":"tree plantation","description":"An agricultural plantation of fast-growing tree species on short rotations for the production of timber, pulp, or fruit.\r\n"},"72":{"name":"tree plantations","description":"An agricultural plantation of fast-growing tree species on short rotations for the production of timber, pulp, or fruit.\r\n"},"85":{"name":"trees outside forests","description":"Trees found in urban areas, alongside roads, or within agricultural land\u0026nbsp;are often referred to as Trees Outside Forests (TOF).\u202f\r\n"},"151":{"name":"unmanaged","description":"Naturally regenerated forests without any signs of management, including primary forest."},"105":{"name":"unmanaged natural forests","description":"Naturally regenerated forests without any signs of management, including primary forest.\r\n"}}}

Citation

“Forest Gain Indicator.” Global Forest Review, updated September 6, 2024. Washington, DC: World Resources Institute. Available online at https://research.wri.org/gfr/forest-extent-indicators/forest-gain.