Terms - Silvicultural Terms in Canada
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immature [jeune (adj.)]
In even-aged management, those trees or stands that have grown past the regeneration stage but are not yet mature. (5)

In uneven-aged management, established trees too young for commercial harvest.


impeder [inhibiteur (n.m.)]
An individual of any value actually impeding the development of another individual of higher grade. (17)


improvement cutting [coupe d'amélioration (n.f.)]
A cutting made in a stand past the sapling stage, primarily to improve composition and quality through the removal of less desirable trees of any species. (1)


improvement planting [plantation d'enrichissement (n.f.)]
Any planting done to improve the value of a stand, and not to establish a regular plantation. (3)


increment [accroissement (n.m.)]
The increase in diameter, basal area, height, volume, quality, or value of individual trees or stands during a given period. (5)


incremental silviculture [sylviculture supplémentaire (n.f.)]
see intensive silviculture


incremental felling [éclaircie préparatoire à  l'ensemencement (n.f.)]
A heavy thinning near the end of the rotation designed to stimulate growth of the trees left to form the final crop. (3)


infilling [regarni (n.m.)]
see fill planting


ingrowth [recrutement (n.m.)]
The volume or number of trees that have grown past an arbitrary lower limit of measurement during a specified period. (1)


insecticide [insecticide (n.m.)]
Any chemical or biological preparation used to kill or disrupt the development of insects. (4)


integrated pest management [gestion intégrée des ravageurs (n.f.)]
The goal of integrated pest management is to advantageously change the pest-host relationship which is a component of a larger socio-ecological system, while minimizing adverse impacts, of any sort, on the rest of the system. (29)


integrated resource management (IRM) [gestion intégrée des ressources (n.f.)]
Management of natural ressources in order to achieve maximum benefits; integrating forest management to nontimber uses and values not only to produce timber, but also to develop the wildlife and recreational capacities of forested areas.


intensive forest management [aménagement forestier intensif (n.m.)]
Basic forest management plus juvenile-stand improvement plus acceleration of artificial regeneration.


intensive silviculture [sylviculture intensive (n.f.)]
Application of cultural measures which, in addition to simply maintaining the forest cover, will allow an increase in the value or volume of the cut.

The term incremental silviculture is defined in the British Columbia Forest Act and thus "intensive silviculture" is no longer used there.

In Ontario, intensive silviculture may be considered to include plantation establishment, e.g., using genetically improved planting stock; intensive site preparation, such as spraying herbicides to reduce competing vegetation before mechanical preparation; and manual weeding of plantations at early stages.


intercropping [culture dérobée (n.f.)]
The raising of a forest crop in conjunction with a temporary agricultural crop. (3)


intermediate crown class [classe de cime intermédiaire (n.f.)]
see crown class: intermediate


intermediate cutting [coupe intermédiaire (n.f.)]
see intermediate treatments


intermediate treatments [traitement intermédiaire (n.m.)]
Any treatment in a stand during that portion of the rotation not included in the final harvest or regeneration period. (1)

cf. tending


intermediate tree [retardataire, intermédiaire (adj.)]
see crown class: intermediate


interplanting [plantation intercalaire (n.f.)]
Planting young trees among existing natural regeneration or previously planted trees of similar age. (1)

This activity is known as fill-in planting in Alberta, considered to be the same as fill planting in Ontario and British Columbia, and called gap planting in Newfoundland.

cf. fill planting


irregular shelterwood system [système des coupes progressives irrégulières (n.m.)]
see shelterwood cutting


irregular stocking [matériel relatif irrégulier (n.m.)]
see stocking: partially stocked


irregular uneven-aged structure [structure inéquienne irrégulière (n.f.)]
Stands that have three or more distinct age classes which do not occupy approximately equal areas. Distribution of diameters is unbalanced. (1)

Also referred to in Ontario as multistoried stands.

cf. regular uneven-aged structure


isolation strip [bande d'isolement (n.f.)]
see buffer


        Terms in the glossary are arranged alphabetically. In some instances, terms within a family (for example, thinning) are grouped together to make it easier for the reader to compare them. In such cases, each member of a family (for example, precommercial thinning) is also listed alphabetically, but the reader is referred to the family name.

        Each term appears in boldface letters and is followed by its equivalent term in French in brackets. Terms used as both nouns and verbs are identified as such by n and v, respectively. The generic of the French equivalent term is offered in this edition, and refers to the dominant noun when the equivalent is not a single word.

        The number in parentheses following a term refers to the source of the definition. These sources are listed below. In many cases, definitions taken from such sources have been paraphrased and/or edited to agree with house style. This publication is the source of those definitions not followed by numbers in parentheses.

1. Adams, D.L., et al. 1989. Recommended changes in silviculture terminology. Unpublished. Silviculture Instructors Subgroup, Silviculture Working Group (D2), Society of American Foresters. Washington, DC.

2. Crcha, J.; Martel, J.; Savard, J. 1977. Normes de traitements sylvicoles. Ministère de l’Énergie et des Ressources, Québec.

3. Ford-Robertson, F.C. 1971. Terminology of forest science, technology practice and products. Society of American Foresters, Washington, DC.

4. Forestry Statistics and Systems Branch, Canadian Forestry Service. 1984. Reporting and summarizing forestry change data—Manitoba pilot study. Petawawa National Forestry Institute, Chalk River, Ont. Inf. Rep. PI-X-36.

5. Haddon, B.D., editor. 1988. Forest inventory terms in Canada. 3rd ed. Canadian Forest Inventory Committee, Forestry Canada.

6. Merrill, D.F.; Alexander, M.E., editors. 1987. Glossary of forest fire management terms. 4th ed. National Research Council of Canada, Canadian Committee on Forest Fire Management, Ottawa. Publication NRCC No. 26516.

7. New Brunswick Department of Natural Resources. No date. Glossary of terms.

8. Ontario Ministry of Natural Resources. 1984. Glossary of terms. Unpublished.

9. Province of Saskatchewan. 1989. Silviculture definitions. Unpublished.

10. Smith, D.M. 1986. The practice of silviculture. 8th ed. John Wiley & Sons, New York.

11. Wright, J.W. 1976. Introduction to forest genetics. Academic Press, New York.

12. Zobel, B.; Talbert, J. 1984. Applied forest tree improvement. John Wiley & Sons, New York.

Sources Added to Second Edition

13. Agriculture Handbook No. 553. U.S. Department of Agriculture. Washington, DC.

14. Holmes, S. 1979. S. Henderson’s dictionary of biological terms. 9th ed. Longman Group Ltd., London.

15. Zumer-Linder, M. 1979. Environmental word-list. Ecological Studies 3. Swedish University of Agriculture Sciences, International Rural Development Centre, Uppsala, Sweden.

16. Forestry Commission Leaflet No. 77. Oxford, UK.

17. Dawkins, H.C. 1958. The management of natural tropical high forest with special reference to Uganda. p. 127–129 in Inst. Paper No. 34, Int. For. Inst., Oxford, UK.

18. Moore, R.; Mills, T. 1977. An environmental guide to Western surface mining. Part two: Impacts, mitigation and monitoring, p. VI.1-VI.9. Fish and Wildlife Service, U.S. Department of the Interior.

19. 1974. A glossary of terms used in range management. 2nd ed. Society for Range Management, Denver, CO.

20. Collocott, T.C. (Ed.). 1971. Dictionary of science and technology. W. & R. Chambers Ltd., Edinburgh.

21. Forest Engineering Research Institute of Canada. 1993. Personal communications.

22. Winters, R.K. (Ed.). 1977. Terminology of forest science, technology, practice and products. English-language version. Addendum 1. Soc. Am. For., Washington, DC.

23. Sutton, R.F.; Tinus, R.W. 1983. Root and root system terminology. Forest Science Monograph No. 24. For. Sci. 29 (Suppl.).

24. Franzese, M.L.; Thompson, T.J.; McNutt, J. 1978. Comp. glossary of forestry related terms. Potlach Corporation, Lewiston.

25. Snyder, E.B. 1972. Glossary for forest tree improvement workers. Southern For. Exp. Stn., For. Serv., US Dep. Agr. 22  p.

26. Steppler, H.A.; Nair, P.K.R. 1987. Agroforestry: A decade of development. ICRAF, Nairobi, Kenya. 276 p.

27. Sutton, R.F. 1985. Vegetation management in Canadian forestry. Govt. Can., Can. For. Serv. Sault-Ste-Marie, Ont. Inf  Rep. O-X-369. 34 p. + Append.

28. Ontario Ministry of Natural Ressources. 1987. Timber management guidelines for the protection of tourism values.

29. Thompson, A.J.; Fleming, R. 1991. Legislative and policy limits to successful integrated pest management in Canada’s forest. For. Chron. 67(5):493-499.