The terms and definitions used in FRA 2000 were based on the consensus agreement of the participants of the Expert Consultation on Global Forest Resources Assessment 2000 in 1996 (Kotka III) (Finnish Forest Research Institute 1996). In 1997, the Intergovernmental Panel on Forests (IPF) endorsed the findings of the consultation and, in particular, supported the single global definition of forest developed in the meeting (UN 1997). The following year, FAO released FRA Working Paper No. 1 (1998) which contained the terms and definitions advocated at Kotka III. Some of the definitions were clarified in 2000 in FRA Working Paper No. 33 (FAO 2000) and in the State of the World's Forests 2001 (FAO 2001) in such a way as to enhance their understanding, without changing their meaning.
DEFINITIONS OF FOREST AND RELATED LAND USE CLASSIFICATIONS AND FOREST CHANGE PROCESSES
In 2000, the basic forest and forest change terms were revisited in light of the experiences gained
during FRA 2000. One driving factor behind this re-examination was the request for input to the Kyoto Protocol process and the elaborations on carbon sequestration in forests. A clear and complete outline of forest change processes was sought. Some of the original formulations for FRA 2000 were therefore modified for clarity and completeness, without changing the meaning of the definitions. The process of further refining forest terms and definitions will continue under the facilitation of FAO, with the clear objective of keeping the base FRA definitions used and ensuring that the time series of forest area data can be continued.
The following terms and definitions, illustrated below, represent the comprehension at the end of the FRA 2000 project.
Forest and related land use classifications
Forest includes natural forests and forest plantations. It is
used to refer to land with a tree canopy cover of more than 10 percent and area
of more than 0.5 ha. Forests are determined both by the presence of trees and
the absence of other predominant land uses. The trees should be able to reach a
minimum height of 5 m. Young stands that have not yet but are expected to reach
a crown density of 10 percent and tree height of 5 m are included under forest,
as are temporarily unstocked areas. The term includes forests used for purposes
of production, protection, multiple-use or conservation (i.e. forest in national
parks, nature reserves and other protected areas), as well as forest stands on
agricultural lands (e.g. windbreaks and shelterbelts of trees with a width of
more than 20 m), and rubberwood plantations and cork oak stands. The term
specifically excludes stands of trees established primarily for agricultural
production, for example fruit tree plantations. It also excludes trees planted
in agroforestry systems.
A forest composed of indigenous trees and not classified as
A forest established by planting or/and seeding in the process
of afforestation or reforestation. It consists of introduced species or, in some
cases, indigenous species.
Other wooded land
Land that has either a crown cover (or equivalent stocking
level) of 5 to10 percent of trees able to reach a height of 5 m at maturity;
or a crown cover (or equivalent stocking level) of more than 10 percent of
trees not able to reach a height of 5 m at maturity; or with shrub or bush cover
of more than 10 percent.
Establishment of forest plantations on land that, until then,
was not classified as forest. Implies a transformation from non-forest to
Natural expansion of forest
Expansion of forests through natural succession on land that,
until then, was under another land use (e.g. forest succession on land
previously used for agriculture). Implies a transformation from non-forest to
Establishment of forest plantations on temporarily unstocked
lands that are considered as forest.
Natural regeneration on forest lands
Natural succession of forest on temporarily unstocked lands
that are considered as forest.
The conversion of forest to another land use or the
long-term reduction of the tree canopy cover below the minimum 10 percent
threshold (see definition of forest and the following explanatory note).
Explanatory note: Deforestation implies the long-term or permanent loss of
forest cover and implies transformation into another land use. Such a loss can
only be caused and maintained by a continued human-induced or natural
perturbation. Deforestation includes areas of forest converted to agriculture,
pasture, water reservoirs and urban areas. The term specifically excludes areas
where the trees have been removed as a result of harvesting or logging, and
where the forest is expected to regenerate naturally or with the aid of
silvicultural measures. Unless logging is followed by the clearing of the
remaining logged-over forest for the introduction of alternative land uses, or
the maintenance of the clearings through continued disturbance, forests commonly
regenerate, although often to a different, secondary condition. In areas of
shifting agriculture, forest, forest fallow and agricultural lands appear in a
dynamic pattern where deforestation and the return of forest occur frequently in
small patches. To simplify reporting of such areas, the net change over a larger
area is typically used. Deforestation also includes areas where, for example,
the impact of disturbance, overutilization or changing environmental conditions
affects the forest to an extent that it cannot sustain a tree cover above the 10
Changes within the forest which negatively affect the
structure or function of the stand or site, and thereby lower the capacity to
supply products and/or services.
Changes within the forest which positively affect the
structure or function of the stand or site, and thereby increase the capacity to
supply products and/or services.
TERMS AND DEFINITIONS AS PRESENTED IN FRA WORKING PAPER NO. 1
The terms and definitions below are taken directly from FRA Working Paper No. 1 (FAO 1998). They represent the formulations used at the beginning of the FRA 2000 process. Although no changes in definitions have occurred during FRA 2000, it is important to note that some slight adjustments and clarifications have been adopted. For example, the general classification of land was called "land cover classification" in 1998, whereas in this report the division into forest, other wooded land and other land is a "land use classification", in that "forest" is defined both by the presence of trees and by the absence of other land uses.
Land cover, general classification
Total area (of country), including area under inland water
bodies, but excluding offshore territorial waters.
Land with tree crown cover (or equivalent stocking level) of more than 10 percent and area of more than 0.5 ha. The trees should be able to reach a minimum height of 5 m at maturity in situ. May consist either of closed forest formations where trees of various storeys and undergrowth cover a high proportion of the ground; or open forest formations with a continuous vegetation cover in which tree crown cover exceeds 10 percent. Young natural stands and all plantations established for forestry purposes which have yet to reach a crown density of 10 percent or tree height of 5 m are included under forest, as are areas normally forming part of the forest area which are temporarily unstocked as a result of human intervention or natural causes but which are expected to revert to forest.
Includes: forest nurseries and seed orchards that constitute
an integral part of the forest; forest roads, cleared tracts, firebreaks and
other small open areas; forest in national parks, nature reserves and other
protected areas such as those of specific scientific, historical, cultural or
spiritual interest; windbreaks and shelterbelts of trees with an area of more
than 0.5 ha and width of more than 20 m; plantations primarily used for forestry
purposes, including rubberwood plantations and cork oak stands. Excludes: Land
predominantly used for agricultural practices
Other wooded land
Land either with a crown cover (or equivalent stocking level)
of 5-10 percent of trees able to reach a height of 5 m at maturity in
situ; or a crown cover (or equivalent stocking level) of more than 10
percent of trees not able to reach a height of 5 m at maturity in situ
(e.g. dwarf or stunted trees); or with shrub or bush cover of more than 10
Land not classified as forest or other wooded land as defined
above. Includes agricultural land, meadows and pastures, built-on areas, barren
Area occupied by major rivers, lakes and reservoirs.
Forest stands established by planting or/and seeding in the process of afforestation or reforestation. They are either:
See also afforestation and reforestation.
Note: Area statistics on forest plantations provided by countries should
reflect the actual forest plantations resource, excluding replanting.
Replanting is the re-establishment of planted trees, either because
afforestation or reforestation failed, or tree crop was felled and regenerated.
It is not an addition to the total plantation area.
Natural forests are forests composed of indigenous trees, not planted by humans. Or in other words forests excluding plantations. Natural forests are further classified using the following criteria:
Subdivisions of natural forests: forest formation
Formations where trees in the various storeys and the
undergrowth cover a high proportion (> 40 percent) of the ground and do not
have a continuous dense grass layer (cf. the following definition). They are
either managed or unmanaged forests, primary or in advanced state of
reconstitution and may have been logged-over one or more times, having kept
their characteristics of forest stands, possibly with modified structure and
composition. Typical examples of tropical closed forest formations include
tropical rain forest and mangrove forest.
Formations with discontinuous tree layer but with a coverage
of at least 10 percent and less than 40 percent. Generally there is a continuous
grass layer allowing grazing and spreading of fires. (Examples are various forms
of cerrado, and chaco in Latin America, wooded savannahs and woodlands in
Subdivisions of natural forests: degree of human
disturbance or modification
Natural forest undisturbed by humans
Forest which shows natural forest dynamics such as natural
species composition, occurrence of dead wood, natural age structure and natural
regeneration processes, the area of which is large enough to maintain its
natural characteristics and where there has been no known human intervention or
where the last significant human intervention was long enough ago to have
allowed the natural species composition and processes to have become
Natural forest disturbed by humans
Managed forests modified by man through sylviculture and
Subdivisions of natural forests: forest composition by
Forest with a predominance (more than 75 percent of tree crown
cover) of trees of broad-leaved species.
Forest with a predominance (more than 75 percent of tree crown
cover) of trees of coniferous species.
Forest on which more than 75 percent of the crown cover
consists of tree species other than coniferous or broad-leaved species (e.g.
tree-form species of the bamboo, palm and fern families).
Forest in which neither coniferous nor broad-leaved species
nor palms nor bamboos account for more than 75 percent of the tree crown
Subdivision of other wooded land
Refer to vegetation types where the dominant woody elements
are shrubs i.e. woody perennial plants, generally of more than 0.5 m and less
than 5 m in height on maturity and without a definite crown. The height limits
for trees and shrubs should be interpreted with flexibility, particularly the
minimum tree and maximum shrub height, which may vary between 5 and 7 m
Forest fallow system
Refers to all complexes of woody vegetation deriving from the
clearing of natural forest for shifting agriculture. It consists of a mosaic of
various reconstitution phases and includes patches of uncleared forests and
agriculture fields, which cannot be realistically segregated and accounted for
area-wise, especially from satellite imagery. Forest fallow system is an
intermediate class between forest and non-forest land uses. Part of the area may
have the appearance of a secondary forest. Even the part currently under
cultivation sometimes has appearance of forest, due to presence of tree cover.
Accurate separation between forest and forest fallow may not always be
Protected areas - IUCN classification for nature
I - Strict nature reserve/ wilderness area
Protected area managed mainly for science or wilderness
protection. These areas possess some outstanding ecosystems, features and/or
species of flora and fauna of national scientific importance, or they are
representative of particular natural areas. They often contain fragile
ecosystems or life forms, areas of important biological or geological diversity,
or areas of particular importance to the conservation of genetic resources.
Public access is generally not permitted. Natural processes are allowed to take
place in the absence of any direct human interference, tourism and recreation.
Ecological processes may include natural acts that alter the ecological system
or physiographic features, such as naturally occurring fires, natural
succession, insect or disease outbreaks, storms, earthquakes and the like, but
necessarily excluding man-induced disturbances.
II - National park
Protected area managed mainly for ecosystem protection and
recreation. National parks are relatively large areas, which contain
representative samples of major natural regions, features or scenery, where
plant and animal species, geomorphological sites, and habitats are of special
scientific, educational and recreational interest. The area is managed and
developed so as to sustain recreation and educational activities on a controlled
basis. The area and visitors' use are managed at a level which maintains the
area in a natural or semi-natural state.
III - Natural monument
Protected area managed mainly for conservation of specific
natural features. This category normally contains one or more natural
features of outstanding national interest being protected because of their
uniqueness or rarity. Size is not of great importance. The areas should be
managed to remain relatively free of human disturbance, although they may have
recreational and touristic value.
IV - Habitat/ species management area
Protected area managed mainly for conservation
through management intervention. The areas covered may consist of nesting
areas of colonial bird species, marshes or lakes, estuaries, forest or grassland
habitats, or fish spawning or seagrass feeding beds for marine animals. The
production of harvestable renewable resources may play a secondary role in the
management of the area. The area may require habitat manipulation (mowing, sheep
or cattle grazing, etc.).
V - Protected landscape/ seascape
Protected areas managed mainly for landscape/seascape
conservation and recreation. The diversity of areas falling into this
category is very large. They include those whose landscapes possess special
aesthetic qualities which are a result of the interaction of man and land or
water, traditional practices associated with agriculture, grazing and fishing
being dominant; and those that are primarily natural areas, such as coastline,
lake or river shores, hilly or mountainous terrains, managed intensively by
humans for recreation and tourism.
VI - Managed resource protection area
Protected area managed for the sustainable use of natural
ecosystems. Normally covers extensive and relatively isolated and
uninhabited areas having difficult access, or regions that are relatively
sparsely populated but are under considerable pressure for colonization or
Forest area available for wood supply
Forest available for wood supply
Forest where any legal, economic, or specific environmental
restrictions do not have a significant impact on the supply of wood. Includes:
Areas where, although there are no such restrictions, harvesting is not taking
place, for example areas included in long-term utilization plans or
Forest not available for wood supply
Forest where legal, economic or specific environmental restrictions prevent any significant supply of wood. Includes:
Volume and biomass
Stem volume of all living trees more than 10 cm diameter at breast height (or above buttresses if these are higher), over bark measured from stump to top of bole.
Excludes: all branches
Commercial growing stock
Part of the growing stock, that consists of species considered as actually or potentially commercial under current local and international market conditions, at the reported reference diameter (DBH).
Includes: species which are currently not utilized, but potentially commercial having appropriate technological properties.
Note: When most species are merchantable, i.e. in the
temperate and boreal zone, the commercial growing stock, in a given area or for
a country, can be close to the total growing stock. In the tropics however,
where only a fraction of all species are merchantable, it may be much
The mass of the woody part (stem, bark, branches, twigs) of trees, alive and dead, shrubs and bushes.
Includes: Above ground woody biomass, stumps and roots.
Excludes: foliage, flowers and seeds.
Above-ground woody biomass
The above ground mass of the woody part (stem, bark, branches, twigs) of trees, alive or dead, shrubs and bushes.
Excludes: stumps and roots, foliage, flowers and seeds.
Fellings and removals
Average volume of all trees, living or dead, measured over bark to a minimum diameter of 10 cm (DBH), that are felled during a given period (e.g. annually), whether or not they are removed from the forest or other wooded land.
Includes: silvicultural and pre-commercial thinnings and
cleanings of trees more than 10 cm (DBH) left in the forest, and natural losses
of trees above 10 cm (DBH).
(Annual) removals that generate revenue for the owner of the forest or other wooded land or trees outside the forest. They refer to "volume actually commercialized" (VAC), i.e. volume under bark actually cut and removed from the forest. This volume may include wood for industrial purposes (e.g. sawlogs, veneer logs, etc.) and for local domestic use (e.g. rural uses for construction).
Includes: removals during the given reference period of trees felled during an earlier period and removal of trees killed or damaged by natural causes (natural losses), e.g. fire, wind, insects and diseases.
Excludes: removals for fuelwood.
Note: Removals as defined above refer to commercial removals,
i.e. harvested timber, both for industrial and local domestic uses. In many
developing countries, removals for fuelwood make up a considerable part of the
total harvested wood. However, data on fuelwood removals are generally scarce
and/or unreliable, and need to be reported separately when national or local
data are available.
Non-wood forest products and forest
Non-wood forest products
Products for human consumption: food, beverages, medicinal plants, and extracts (e.g. fruits, berries, nuts, honey, game meats, mushrooms, etc.).
Fodder and forage (grazing, range).
Other non-wood products (e.g. cork, resin, tannins, industrial
extracts, wool and skins, hunting trophies, Christmas trees, decorative foliage,
mosses and ferns, essential and cosmetic oils, etc.).
Protection (against soil erosion by air or water, avalanches, mud and rock slides, flooding, air pollution, noise, etc.).
Social and economic values (e.g. hunting and fishing, other leisure activities, including recreation, sport and tourism).
Aesthetic, cultural, historical, spiritual and scientific
values (including landscape and amenity).
Forest cover changes
Refers to change of land cover with depletion of tree crown
cover to less than 10 percent. Changes within the forest class (e.g. from closed
to open forest) which negatively affect the stand or site and, in particular,
lower the production capacity, are termed forest degradation.
Takes different forms, particularly in open forest formations,
deriving mainly from human activities such as overgrazing, overexploitation (for
fuelwood or timber), repeated fires, or due to attacks by insects, diseases,
plant parasites or other natural sources such as cyclones. In most cases,
degradation does not show as a decrease in the area of woody vegetation but
rather as a gradual reduction of biomass, changes in species composition and
soil degradation. Unsustainable logging practices can contribute to degradation
if the extraction of mature trees is not accompanied with their regeneration or
if the use of heavy machinery causes soil compaction or loss of productive
New plantations: afforestation
Artificial establishment of forest on lands which previously
did not carry forest within living memory.
New plantations: reforestation
Artificial establishment of forest on lands which carried
All trees classified botanically as Angiospermae. They
are sometimes referred to as "non-coniferous" or "hardwoods".
All trees classified botanically as Gymnospermae. They are
sometimes referred to as "softwoods".
Species classified by an objective process (e.g. national "Red
Book") as being in IUCN categories "critically endangered" and "endangered". A
species is considered to be "critically endangered" when it is facing an
extremely high risk of extinction in the wild in the immediate future. It is
considered "endangered" when it is not critically endangered but is still facing
a very high risk of extinction in the wild in the near future.
Species is endemic when found only in a certain strictly
limited geographical region, i.e. restricted to a specified region or
Indigenous tree species
Tree species which have evolved in the same area, region or
biotope where the forest stand is growing and are adapted to the specific
ecological conditions predominant at the time of the establishment of the stand.
May also be termed native species or autochthonous species.
Introduced tree species
Tree species occurring outside their natural vegetation zone,
area or region. May also be termed non-indigenous species.
Managed forest/other wooded land
Forest and other wooded land that is managed in accordance
with a formal or an informal plan applied regularly over a sufficiently long
period (five years or more).
The function of forest/other wooded land in providing
protection of soil against erosion by water or wind, prevention of
desertification, the reduction of risk of avalanches and rock or mud slides; and
in conserving, protecting and regulating the quantity and quality of water
supply, including the prevention of flooding. Includes: Protection against air
and noise pollution.
A woody perennial with a single main stem, or in the case of
coppice with several stems, having a more or less definite crown. Includes:
bamboos, palms and other woody plants meeting the above criterion.
FAO. 1998. FRA 2000: Terms and definitions. FRA
Working Paper No. 1. Rome.
FAO. 2000. On definitions of forest and forest change. FRA Working Paper No. 33. Rome.
Finnish Forest Research Institute. 1996. Expert consultation on Global Forest Resource Assessment 2000. Kotka III. Proceedings of FAO Expert Consultation on Global Forest Resources Assessment 2000 in cooperation with ECE and UNEP with the Support of the Government of Finland (KOTKA III). Kotka, Finland, 10-14 June 1996. Eds. Nyyssonen, A. & Ahti, A. Research Papers No. 620. Helsinki. Finland.
UN. 1997. Report of the Ad Hoc Intergovernmental Panel on Forests on its Fourth Session. New York, 11-27 February 1997. E/CN.17/1997/12. New York.