(yes, 98) (alleged) definitions of Old GrowthForests!
Bob and Colby,
An FAO List of Ninety-eight (yes, 98) (alleged) definitions of
Old Growth Forests mostly complete with URL's! From an FAO web
1. Future old growth forest: Forests contiguous to old growth
forests that: (1) exhibits some but not all old growth
characteristics, (2) occurs in direct association with and as an
integral part of an old growth forest, and (3) has the capacity
to protect old growth forest areas because of their forest
characteristics and location.
2. (Canada - BC) - Forests on the coast > 250 years old; and
forests in the interior > 140 years old for most tree
species, and > 120 years old for lodgepole pine and deciduous
3. (Canada - BC) Forest that contains live and dead trees of
various sizes, species composition and age class structure that
are part of a slowly changing but dynamic ecosystem. Old growth
forests include climax forests, but do not exclude sub-climax or
even mid-seral forests. The age and structure of old growth
varies significantly by forest type and from one biogeoclimatic
zone to another. (Wells, et al. 1998)
4. (Canada) A stand dominated by mature or overmature trees that
has not been significantly influenced by human activity. The
stand can contain various ages and species of vegetation.
5. (Finland) A forest stand exceeding the regular cycle by 20
years. Lauri Karvonen 24.4.2000. Guidelines for Landscape
6. (Foret ancienne, rodal maduro). A forest dominated by mature
organisms that have originated naturally from those endemic to
the forest or its surrounds, in which the genetic, species and
structural diversity have not been significantly changed by
human activity. Forestry Chronicle 70(6):669 1994.
7. (Philippines) Forest predominantly stocked with mature trees
with less than 25 percent of the mature stand volume removed by
8. (Primary, Original) Forests that have never been clear cut
and that have little or no evidence of past human activity. Such
forests may have been grazed, experienced limited exploitation
of valuable tree species, and their floors may have been burned
by Amerindians and European colonists (Duffy and Meier 1992).
9. (Timber) - Timber from a mature, naturally established forest
(Georgia Forestry Commission).
10. (USA - USFS - Monongahela NF) - Stands with large, mature,
or overmature trees comprising a plurality of the stocking...
usually having a multi-layered canopy in trees of various age
classes... includ[ing] dead trees and relatively large amounts
of decaying material on the forest floor. USDA FS Monongahela
National Forest, West Virginia (1986).
11. (USA-Massachusetts) - An area of contiguous forest that (1)
shows no evidence of significant human, post-European
disturbance that originated on site, (2) has a significant
component of older trees that are greater than fifty percent of
the maximum longevity for that particular species, (3) is at
least five acres in size, and (4) has the capacity for
self-perpetuation, or (5) has the characteristics of a forest
which, when found in combination together, are indicative of an
old growth forest and which otherwise meets the criteria
established by regulation by the Secretary.
12. (USA-Nevada) "Old growth" refers to stands of
essentially undisturbed virgin timber on which less than 25
percent of the volume has been removed by cutting, fire or other
causes. Source: NRS 528.019
13. (USA-USFS) The USFS has developed Old-Growth definitions for
each of the major forest types found in the United States. These
are available from the Regional Offices of the US Forest
Service. A generic definition is as follows: Ecosystems
distinguished by old trees and related structural attributes.
Old growth encompasses the later stages of stand development
that typically differ from earlier stages in a variety of
characteristics which may include tree size, accumulations of
large dead woody material, number of canopy layers, species
composition, and ecosystem function. Description - The age at
which old-growth develops and the specific structural attributes
that characterize old growth will vary widely according to
forest type, climate, site conditions, and disturbance regime.
For example, old-growth in fire-dependent forest types may not
differ from younger forests in the number of canopy layers or
accumulation of down woody material. However, old-growth is
typically distinguished from younger growth by several of the
following attributes: 1) large trees for species and site, 2)
wide variation in tree sizes and spacing, 3) accumulations of
large-size dead standing and fallen trees that are high relative
to earlier stages, 4) decadence in the form of broken or
deformed tops or bole and root decay, 5) multiple canopy layers,
and 6) canopy gaps and understory patchiness. Old-growth is not
necessarily "virgin" or "primeval."
Old-growth could develop following human disturbances. USFS
14. (USA-Vermont) A forest stand in which natural processes and
succession have occurred over time undisturbed by human
Vermont Forest Resource Plan.
15. (Russia) Old-growth forests are forests originated through
natural successions and have not experienced significant human
impact over a long period of time. Under significant human
impact we understand: clearcutting or intensive selective
logging; large scale human-induced fires; intensive and regular
application of chemicals such as pesticides, herbicide,
fertilizers, etc.; severe industrial pollution; forest
reclamation; intensive recreation, etc. Under the long period of
time we understand the time, which exceeds the lifetime of the
dominant tree species for a particular forest type.
16. (Victorian forests) - Forest which contains significant
amounts of its oldest growth stage in its upper stratum and has
been subjected to any disturbance, the effect of which is now
(Woodgate et al. (1994).
17. A classification of forest stands that describes an
ecologically mature ecosystem. Where information is not
available for ecological classification, age or size of dominant
trees, or both, are used. (Bolsinger and Waddell 1993)
18. A climax forest that has never been disturbed by man. The
old growth forests can be classified as per the age and
19. A forest characterized by growth displaying successional
stages that occur only after a relatively long period of time
without a catastrophic disturbance. In Minnesota, old-growth
forests probably develop after 125-150 years without a
catastrophic disturbance (adapted from Old-growth Forests in
Minnesota. A Preliminary Report, Minnesota DNR Natural Heritage
20. A forest dominated by mature organisms that have originated
naturally from those endemic to the forest or its surrounds, in
which the genetic, species and structural diversity have not
been significantly changed by human activity.
21. A forest dominated by mature trees that has not been
significantly influenced by human activity" (CCFM 1997:
22. A forest or stand that (1) contains at least one, preferably
several, tree species that have attained an average age of 150
years or more in the mature specimens; (2) has gone undisturbed
by human activity for a time interval sufficient for the
establishment of old-growth characteristics, and; (3) contains a
density of at least 8 mature trees in the 150 year-old age
bracket per acre. Leverett (1991).
23. A forest relatively old and relatively undisturbed. NOTE:
(1) The term "old" varies by the species or group of
species in a stand. (2) Some individuals believe old growth to
be an uncut, virgin forest with very little man-made
disturbance, while other individuals believe an old growth
forest can be created by limiting future disturbance and
creating certain characteristics evident in uncut virgin stands
and thus termed a managed old growth forest.
24. A forest stand usually at least 180-220 years old with
moderate to high canopy closure; a multi-layered, multi-species
canopy dominated by large overstory trees; high incidence of
large trees, some with broken tops and other indications of old
and decaying wood ("decadence"); numerous large snags;
and heavy accumulations of wood, including large logs on the
ground. From: Kathyfirstname.lastname@example.org
(Kathy Jope) also http://www.studyweb.com/Agriculture/
25. A forest that contains live and dead trees of various sizes,
species, composition, and age class structure. Old-growth
forests, as part of a slowly changing but dynamic ecosystem,
include climax forests but not sub-climax or mid-seral forests.
The age and structure of old growth varies significantly by
forest type and from one biogeoclimatic zone to another.
26. A forest that contains live and dead trees of various sizes,
species, composition and age-class structure. The age and
structure of old growth varies significantly by forest type and
from one biogeoclimatic zone to another.
27. A forest that has not undergone a stand-replacing
disturbance such as logging or fire, such that succession has
28. A forest that is ecologically mature and has been subjected
to negligible unnatural disturbance such as logging, roading or
29. A late stage of forest succession. Although the specific
characteristics of old-growth stands vary with species
composition and history, some commonly expected attributes in
mesic forests on productive sites include-an abundance of large
trees at least 180 to 200 years old; a multi-layered,
multi-species canopy dominated by large overstory trees with
moderate to high closure; numerous trees with broken tops,
snags, and large logs.
30. A mature forest which has not been disturbed by human
activity. Also known as virgin forest. An increasingly rare, and
increasingly valued, element of the wilderness. The lumbermen
see it as something else, as evidenced in this not-so-subtle
definition from an industry web site: Old Growth Forest: Forest
stands in which the dominant cover types are mature or
over-mature trees that have reached their maximum size. No
harvest has occurred among these large, old trees and dead and
fallen trees are as common as standing trees. Boundary Waters
31. A natural progression of forest growth without evidence of
man's influence. Sydney Haskell, Carmanah Forestry Society.
(Wells, et al. 1998)
32. A post-rotational forest http://www.ameteam.ca/glossary.htm
33. A primary or a secondary forest which has achieved an age at
which structures and species normally associated with old
primary forests of that type have sufficiently accumulated to
act as a forest ecosystem distinct from any younger age class.
34. A stand of mature or overmature trees relatively
uninfluenced by human activity. The stand can contain multiple
layers of tree canopies, and various ages and species of
35. A very old and complex forest community, usually at least
200 years old, characterized by a mixture of species, trees of
varied size and age, snags, and extensive amounts of wood on the
36. An ecosystem distinguished by the presence of populations of
old trees that is not necessarily in late successional condition
or tree from evidence of human activity (Spies 1997).
37. An undisturbed forest with trees that are more than 200
years old. It is characterized by fallen trees, trees with
broken tops and mature and dying trees.
38. Ancient forests. http://www.nrdc.org/sitings/lookup/teraa.html
39. Any ecosystem composed of dominant and codominant trees that
40. Ecologically mature and have been subjected to negligible
human-induced disturbance such as logging, roading and clearing
or, if subject to any disturbance, the effect of which is now
negligible. Oldgrowth forests are usually dominated by trees
which exhibit late-mature or senescent growth stages in the
41. Ecologically mature forest that has been subject to
negligible levels of disturbance such as logging, roading and
clearing. The definition focuses on forest in which the upper
stratum or overstorey is in the late mature or overmature growth
42. Ecologically mature forest where the effects of disturbances
are now negligible.
43. Ecosystems distinguished by old trees and related structural
attributes. Specific attributes vary according to forest type,
climate, site conditions, and disturbance regime.
44. Ecosystems distinguish by old trees and related structural
attributes. Old-growth forests are characterized by larger tree
size, high accumulations of large dead woody material, multiple
canopy layers, species composition, and ecosystem function. The
structure and function of an old-growth ecosystem will be
influenced by its stand size and landscape position and context.
45. Forest conditions often including multiple canopy layers,
variety in tree sizes and species, variety of tree ages
including mature trees, and standing and dead woody material.
46. Forest having the following structural characteristics: 1.
An abundance of old trees, recognizable by the asymmetrical
shapes, relatively long trunks free of low branches (i.e.,
in-forest as opposed to open-grown shapes), deeply furrowed or
plated bark, signs of heartwood decay, large prominent root
structures, flattened crowns with protruding dead limbs, large
thick limbs, and trunks often showing a twist that develops with
age; 2. Fallen logs in all stages of decomposition,
crisscrossing the forest floor and lying in and across stream
beds, covered by moss and lichens; 3. Plentiful snags (standing
dead trees); 4. Canopy gaps, large and small, formed from trees
that have fallen; 5. Undulating forest floor, expressed in
randomly scattered pits and mounds where trees have fallen over
and decomposed; 6. Majority of tree species that fall into the
late successional class and a conspicuous absence of multiple-stemed
trees; 7. Minimal of signs of human disturbance. http://www.canadian-forests.com/fsc-glossary.html
and Eastern Old-Growth Forests: Prospects for Rediscovery and
Recovery (M.B. Davis (Ed.) 1996. Island Press, Washington, DC).
47. Forest in which the upper stratum is ecologically mature and
has been subjected to negligible unnatural disturbance such as
logging, road-building and clearing.
48. Forest stand dominated by trees reaching natural death; the
last stage in forest succession.
49. Forest stand dominated by trees reaching natural senescence;
the last stage in forest succession.
50. Forest stands well beyond the rotation age for managed
forests. Canadian Pacific Forest Products Ltd. (Wells, et al.
51. Forest that contains live and dead trees of various sizes,
species, composition and age class structures. Old growth
forests, as part of a slowly changing but dynamic ecosystem,
including climax forests but not sub-climax or mid-seral
52. Forest that has a significant proportion of the oldest
discernible growth stage(s) in its overstory and negligible
structural evidence of disturbances.
53. Forest that is ecologically mature and has been subjected to
negligible unnatural disturbance such as logging, roading and
clearing. The definition focuses on forest in which the upper
stratum or overstory is in the late mature to overmature growth
phases. (The National Forest Policy Statement (Commonwealth of
Australia 1992) identified.
54. Forest which has not had significant unnatural disturbances
altering its content or structure since European settlement.
55. Forest with uninterrupted growth of more than 175 years
56. Forests having a long, uninterrupted period of
development...substantially free of human influences or natural
disturbances... Whitney (1987).
57. Forests that either have never been cut or have not been cut
for many decades. Forests characterized by a large percentage of
58. Forests which have never been logged or developed.
59. Forests with some very old trees. These forests have not
been disturbed by major hurricanes, fires, or human actions in
the last 200 to 250 year.
60. Generally, a forest stand that has reached a stage of
61. Individual trees that are beyond the age of biological
maturity, or stands that contain old growth trees as well as
some large snags, and logs on the ground.
62. Later stages in forest development that are often
compositionally and always structurally distinct from earlier
successional stages. Franklin and Spies 1991.
63. Later stages of forest development that are often
compositionally and always structurally distinct from earlier
stages. Old-growth forests contain trees that are large for
their species on a site. In addition, old growth is usually
charactertized by a variety of tree sizes, abundant large snags
and logs, and a developed, but patchy understory. Old-growth
typically exhibits high diversity in structural attributes due
to varied stand disturbance histories, variable plant species
mixes among sites, and interactions with adjacent stands.
Structural characteristics are dynamic and old-growth stands do
not always contain all of the attributes used to describe them.
However, forests that most clearly match the full range of
structural features for old-growth will most likely provide the
full array of associated functional characteristics. (Mike
Chapel, California Board of Forestry) Source: Beardsley_Debbyemail@example.com
64. Mixed-mesophytic old-growth, includes large trees, basal
area, diverse (native) understories, windthrow mounds, snags,
woody debris, etc. Martin (1992).
65. Old forests often containing several canopy layers, variety
in tree sizes and species, trees at least 180 to 220 years old,
and standing and dead woody material.
66. Old forests valuable in nature conservation terms have
usually greatly exceeded the regeneration ages stipulated in
forestry data. The trees are normally of varying sizes and
species, and form multiple canopy layers, although spruce forest
at a late successional stage also qualifies. Old stumps or other
minor traces of human activity do not necessarily reduce the
conservation value of a forest. Old age and competition have
increased the amount of natural removal, and often also the
amount of damage naturally suffered by the trees. The Working
Group on the Protection of Old Forests on State Lands in
67. Old forests which often contain several canopy layers,
variety in tree sizes and species, decadent old trees, and
standing and dead woody material.
68. Old growth and ancient forests are essentially the same
thing. "Ron Muir" firstname.lastname@example.org
69. Old growth forests can be loosely described as forests that
look largely as they would appear if Europeans had not settled
North America. They are forests that have suffered little or no
logging or grazing.
70. Old growth, virgin forest -- (forest or woodland having a
mature or overmature ecosystem more or less uninfluenced by
Forests which have never been logged or developed.
71. Old multi-story forest - a forest stand with moderate to
high canopy closure-a multi-leveled and multi-species canopy
dominated by large overstory trees; high incidence of large
trees, some with broken tops and other indications of old and
decaying wood; numerous large snags; and heavy accumulations of
wood, including large logs on the ground.
72. Old-growth forests are ecologically mature and have been
roading and clearing or, if subject to any disturbance, the
effect of which is now negligible. Oldgrowth forests are usually
dominated by trees which exhibit late-mature or senescent growth
stages in the upper stratum.
73. Old single story forest - single canopy layer consisting of
large or old trees. Understory trees are often absent, or
present in randomly spaced patches. It generally consists of
widely spaced, shade-intolerant species, such as ponderosa pine
and western larch, and high frequency fire regimes.
74. Old-growth forest i.e. ancient forest means a natural-state
(or close) forest where the amount of dead wood is tens of cubic
meters per hectare. Ilkka Hanski (1999) Helsingin Sanomat
75. Old-growth forests are natural forests with pronounced
variations in the ages of the trees, multiple-layered
vegetation, and a great abundance of old trees and large pieces
of dead wood in different stages of decay. Swedish FSC standard
76. Old-growth forests contain threatened ecosystems and
species, or endemic species. They can also be large
landscape-level forests capable of supporting natural ecological
patterns. The Taiga Rescue Network
77. Old-growth stands must include at least six trees per acre
that are more than 30 to 32" in diameter and more than 200
years in age. The stands must have multilayered canopies (except
within mixed evergreen forests) and hold minimal amounts of
large standing snags more than 20 " in diameter and fallen
logs at least 24" in diameter. 1986 Old-Growth Definition
Task Force of the Forest Service interim definition.
78. Old-growth tree. The closest scientific description is that
it's a tree that is beyond its pathological rotation age--or
simply a tree living beyond its maturity.
79. Original, intact forest land that has not yet been
significantly degraded by people.
80. Relatively old and relatively undisturbed by humans. Hunter
81. Stands in primary or secondary forests that have developed
the structures and species normally associated with old primary
forest of that type have sufficiently accumulated to act as a
forest ecosystem distinct from any younger age class.
82. Stands in which the relic trees have died and which consist
entirely of trees which grew from beneath the canopy. Oliver and
83. Stands in which the relic trees have died and which consist
entirely of trees which grew from beneath... and which have
developed in the absence of allogenic processes".
Transition old-growth "contains some trees which began
after the initial disturbance and also large and numerous
younger trees of allogenic origin". Oliver and Larson
(1996) and Leverett (1996).
84. Stands regenerated by natural succession, with a substantial
amount of old trees and deadwood, and often with an uneven age
85. Stands that are "overmature, past the point of maximum
growth, etc. Leverett (1996). http://wvnvm.wvnet.edu/~rlanden/oldgrth.htm
86. Stands with a high percentage (>50%) of the canopy trees
over half of the maximum life span of the representative trees,
a few trees near the maximum life span, no recorded history or
discernible signs of human disturbance, a "late
successionary" species composition, and a set of
characteristics associated with mature, nature-managed forests.
87. Stands with canopy trees usually 150 years old or older but
no fixed percentage, trees need not be near maximum life span,
but forest must possess a set of characteristics associated with
mature forest. Leverett (1996).
88. The (usually) late successional stage of forest development.
note 1 - old-growth forests are defined in many ways; generally,
structural characteristics used to describe old-growth forests
include (a) live trees; number and minimum size of both seral
and climax dominants, (b) canopy conditions: commonly including
multilayering, (c) snags: minimum number of specific size, and
(d) down logs and coarse woody debris: minimum tonnage and
numbers of pieces of specific size. note 2 - old-growth forests
generally contain trees that are large for their species and
site and sometimes decadent (overmature) with broken tops, often
a variety of tree sizes, large snags and logs, and a developed
and often patchy understory. note 3 - stand age, although a
useful indicator of old growth, is often considered less
important than structure because (a) the rate of stand
development depends more on environment and stand history than
age alone, and (b) dominants are often multiaged. note 4 - due
to large differences in forest type, climate, site quality, and
natural disturbance history (e.g. fire, wind, and disease and
insect epidemics), old-growth forests vary extensively in tree
size, age classes, presence and abundance of structural
elements, stability and presence of understory. note 5 - the
minimum area needed for an old-growth forest to be a functional
ecological unit depends on the nature and management of
surrounding areas; small areas often do not contain all
old-growth elements. note 6 - an old-growth forest is commonly
perceived as an uncut, virgin forest with very little
human-caused disturbance; some believe that the time taken for
stands to develop old-growth structure can be shortened by
silvicultural treatments which the area occupied by each species
per unit area is estimated by eye. note - this method is
contrasted with the weight method - synonym ocular plot
estimate, plot estimate method, square-foot method (Helms 1998).
(Harold T Nygren)
89. The forest-state that stretches from the time of dominant
stand height growth cessation, through to and including the
stable forest climax. Western Canada Wilderness Committee.
(Wells, et al. 1998).
90. The old growth forests have been described by the adjective
primeval, ancient, wilderness, virgin, pristine while in
forester's terminology they are called as over-matured,
decadent, and senescent, old growth. The old growth forests may
be defined as a climax forest that has never been disturbed by
man. The old growth forests can be classified as per the age and
91. The seral stage after mature, which is the potential plant
community capable of existing on a site, given the frequency of
natural disturbance events. In forests of the Pacific region,
old growth often begins around age 200 and continues until a
stand replacing event takes place. Depending on the frequency
and intensity of disturbances, and site conditions, old-growth
forest will have different structures, species compositions, and
92. Those mature and over-mature forests which occupy sites
which have not previously been impacted by the hand of man.
Fletcher Challenge Ltd. (Wells, et al. 1998).
93. Timber stands with the following characteristics: large
mature and over-mature trees in the overstory, snags, dead and
decaying logs on the ground, and a multi-layered canopy with
trees of several age classes.
94. To most people "old growth" means big trees. The
U.S. Forest Service definition is "a forest with trees 200
years or older, snags (standing dead trees), and down woody
debris on the forest floor."
95. Uncut virgin forest; a forest that has not undergone a
stand-replacing disturbance such as logging or a crown fire,
such that succession has not occurred.
96. Undisturbed primary forest, typically diverse in species and
age of constituents, and is a result of competition and
long-time natural selection International Dendrological Research
Institute Glossary -
97. Virgin and old, second-growth forests containing trees that
are often hundreds, sometimes thousands, or years old.
98. Virgin timber.