Forestry glossary

Trees of Canada's forest

Term Definition French
Accessory species A species of less commercial value than the principal species but sometimes useful in assisting the latter and liable to influence the method of treatment to some degree. Essences auxiliaires
Acorn Hard fruit of the oak tree, which contains the seed. Gland
Advance regeneration Young trees under existing stands capable of becoming the next crop. Regeneration established before logging that has survived the logging operation. Régénération préexistante
Age class A distinct group of trees or portion of growing stock recognized on the basis of age. Classe d’âge
Age gradation An age class of one or at the most a few years. Sous-classe d’âge
Air pruning Limiting extension of a root system beyond a container by exposure to air. Élagage aérien
All-aged Of a forest, crop, or stand that contains trees of all, or almost all, age classes, including those of exploitable age. De tous âges
Anthracnose Foliar disease characterized by reduced growth of some portions of the lobes and by the development of necrotic lesions between the veins and on the leaf margins; these lesions may spread to the entire leaf and then the buds and, in extreme cases, the twigs. Anthracnose
Antigen A substance that the organism identifies as foreign, hence triggering the release of antibodies as a defence response. Antigène
Apex Tip or top of an animal or plant structure. Apex
Arboreal Pertaining to the culture of trees. Arboricole
Arboriculture The cultivation, that is, growing and tending, of trees and shrubs, individually or in small groups, generally for ornament, protection, and instruction rather than direct use or profit. Arboriculture
Artificial regeneration Renewal of a tree crop by direct seeding or by planting seedlings or cuttings. Régénération artificielle
Asexual reproduction Reproduction without fertilization. New individuals may develop from vegetative parts such as tubers, bulbs, or rooted stems, or from sexual parts such as unfertilized eggs or other cells in the ovule. Propagation asexuée
Asymmetrical Having corresponding parts that are irregularly arranged in relation to one another. Opposite of symmetrical. Asymétrique
Atrophied Describes an organ or part of a body that is reduced in size, rudimentary. Atrophié
Auger planting Setting plants in loosened soil replaced in or brought to a dug hole using an auger. Plantation à la tarière
Autotroph An organism capable of synthesizing the organic nutrients it needs from the mineral compounds present in nature. Plants and many bacteria are autotrophs or producers. Autotrophs do not need to obtain their nutrients from other living organisms. By contrast, heterotrophs cannot make their own food and so they feed on the tissues of other organisms. Organisme autotrophe
Ball planting Setting out trees with their roots left undisturbed in a dug-out clod of soil. Note: if trees are bare-rooted, and roots are enclosed in a rough ball of soil, they are properly termed balled. Plantation en mottes
Bark The outer covering of trees. Écorce
Bark stripping Removing the bark of a tree in narrow strips. Écorçage
Basal bark treatment A treatment for killing trees and brush in which a herbicide is applied, by sprayer or brush, to a band of bark encircling the basal portion of the stem. Traitement arboricide cortical (à la base de l’arbre)
Base of tree Part of the tree consisting of the first 25 cm of trunk. Base de l'arbre
Basic silviculture All the silvicultural practices required to achieve free-growing (or established) regeneration of desired species at specified densities and stocking. Sylviculture de base
Basket planting Setting out young trees, etc., in loosely-woven baskets in which they have been raised from seed or to which they have been transferred from the seed bed. Plantation en paniers
Biodiversity The collection of life on earth; the natural patterns that form from all the species of life (species diversity), the genes that each of them possess (genetic diversity), as well as the ecosystems which these species form (ecosystem diversity). Biodiversité
Blade Thin, flat part of a leaf. Limbe
Blight Rapid browning or blackening of leaves, which subsequently die, caused by the deterioration of growing tissues. Brûlure
Blister Circular bulge caused by the excessive growth of cells in part of a leaf, often with fungal cells mixed in. Cloque
Boreal forest One of three main forest zones in the world (see also tropical forest, temperate forest) located in northern regions and is characterized by the predominance of conifers (such as pine, spruce, larch and fir) and some deciduous (such as poplar and birch). The boreal forest (singular) is a colloquial term often used to refer to the overall forested area within the boreal zone, and sometimes to refer to the boreal zone itself because forests dominate this landscape. Boreal forests (plural) is the preferred term for the forested areas within the boreal zone. Forêt boréale
Box pruning Lateral root pruning on four sides of nursery stock in situ. Previous undercutting is usually implicit. Élagage latéral (des racines)
Branch Secondary woody stem arising from the trunk of a tree and bearing shoots. Branche
Breast height The standard height, 1.3 m above ground level, at which the diameter of a standing tree is measured. On sloping ground, breast height is usually measured on the uphill side of the tree. Hauteur de poitrine
Brush Shrubs and stands of short, scrubby tree species that do not reach merchantable size. Sometimes includes woody and herbaceous plants that impede regeneration or growth of desirable species. Often rated as "brush hazard". Broussailles
Bud Plant organ containing the immature tissues that will become a leaf, branch or flower. Bourgeon
Budding Grafting by inserting a bud, with a small amount of tissue, into a slit or hole made in the bark of a stock plant. After union has formed, the portion of the stock plant above the bud is removed. Écussonnage
Bullet planting Setting out young trees grown in bullet-shaped rigid plastic tubes, which are injected into the ground by a spring-loaded gun, sometimes into prepared holes. Plantation en cartouches
Callus Thickening and hardening of the cambium tissues which occur as part of a plant's response to a wound. Cal
Cambium Fast-growing tissue that produces wood and phloem (vascular cambium) and bark (cork cambium). Cambium
Canker Lesion of the cambium and the living bark of trees that alters and kills these tissues in a localized area. Chancre
Canopy class syn. canopy cover class, crown class Any class into which crops or stands may be divided on the basis of the degree of closure. Classe de couvert
Carbon A chemical element highly abundant in nature and easily capable of forming polymers. Its unique properties make carbon the chemical basis of all biological compounds—and therefore, the chemical basis of life. Carbon is incorporated into biological processes and biomass mainly through plant photosynthesis. (See also carbon dioxide.) Carbone
Carbon dioxide (CO2) A colourless, odourless, non-combustible gas. Humans and all other living organisms give off carbon dioxide in respiration and decomposition. Trees and other plants absorb it and use it during photosynthesis. CO2 also emitted as a by-product of burning fossil fuels. Dioxyde de carbone (CO2)
Carbon sequestration The uptake and storage of carbon. Trees and plants, for example, absorb carbon dioxide, release the oxygen and store the carbon. Fossil fuels were at one time biomass and continue to store the carbon until burned. Piégeage de carbone
Carbon sink A carbon reservoir that absorbs and stores carbon from another part of the carbon cycle. A sink stores more carbon than it emits to the atmosphere. This store of carbon can also be termed a reservoir or pool. Although a growing forest can be considered a carbon sink, when the forest stops growing and its trees die and start decomposing, it becomes a carbon source, because it emits more carbon than it stores. Puits de carbone
Carpophore Structure bearing the spores of a fungus, often composed of a cap and a stem. Carpophore
Catkin A drooping cluster of flowers or fruits on a flexible axis (resembling the tassels on wheat). Chaton
Cellulose A polymer of glucose molecules, used by plants as a structural supporting material. Paper is made up of cellulose. Cellulose
Cellulose A carbohydrate (sugar-based biopolymer compound) that is the main structural component of green plants. (See also carbon.) Cellulose
Chromosome A single DNA molecule encoding a portion or all of a living organism’s genetic information; threadlike and located in the cell’s nucleus in higher organisms, circular in bacteria. Each species has a characteristic number of chromosomes. Chromosome
Class Taxonomic level between Phyllum and Order. Eg, class Insecta Classe
Clear wood Knot-free wood formed subsequent to pruning. Bois sans défaut
Climate change adaptation An adjustment in natural or human systems in response to actual or expected climatic stimuli. Adaptation au changement climatique
Cluster Group of flowers or fruits borne on a common axis. Grappe
Commercial forest Forest land that is able to grow commercial timber within an acceptable time frame and is designated for such a purpose. Forêt d'intérêt commercial
Competitive exclusion In ecology, principle (also known as Gause’s principle) that states no two species can occupy exactly the same fundamental niche indefinitely in a habitat where they are competing for the same essential resource, and that one species will crowd out the other. Exclusion compétitive
Composition The proportion of each tree species in a stand expressed as a percentage of the total number, basal area, or volume of all tree species in the stand. Composition
Compound leaf A leaf with two or more leaflets attached to a single leaf stem. Feuille composée
Cone Reproductive structure of conifers consisting of a central axis covered with scales that are tightly pressed together. At maturity, it contains the seeds. Cône
Cone collection Harvesting of cones after seed maturation but before their dispersal. Récolte de cônes
Cone rake A device for collecting cones from a standing tree; it is lowered from a helicopter, over the crown of a tree. Cones or cone-bearing branches are removed and retrieved by the device. Cueilleur de cônes
Conifer Member of a group of trees commonly called softwoods or gymnosperms. The word gymnosperm, from the Greek gymnos (naked) and sperma (seed), means "naked-seeded." This refers to the fact that conifer seeds are not contained in fruit tissue. The seeds are instead borne on scales, which are grouped together to form cones. Most conifers have persistent foliage consisting of needles or scales. Conifère
Contained root A root that does not elongate beyond the confines of the original rooting volume within a container, even when outplanted with the container removed. Racine contenue
Container Portable receptacle (pot, bag, or linked spaces) to hold rooting medium for growing planting stock. Récipient
Continuous boreal forest Main subarea of the vast boreal zone, which is characterized by relatively dense stands containing primarily boreal coniferous species and shade-intolerant deciduous trees. Forêt boréale continue
Contour planting Setting out of young trees along a contour line. Plantation en bandes de niveau
Corridor planting Setting trees in parallel rows, generally at regular intervals between and in lines, on land either wholly or partially cleared. Plantation en lignes
Crop The harvestable vegetation growing on a forest area, more particularly the major woody growth forming the forest crop. Peuplement forestier
Crop tree Any tree selected to become or forming a component of the final crop. Arbre du peuplement final
Cross pollination The fertilization of an egg in one plant by a sperm cell found in a pollen grain of another plant. The resulting seed will have the hereditary characteristics from both parents. Pollinisation croisée
Crown The upper part of a tree. Cime
Crown class Trees in a forest with crowns of similar development and occupying a similar position in the canopy; the term applies to groups of trees. Classe de cime
Crown closure class Any interval into which the range of proportions of ground area covered by the vertically projected tree crown areas of a stand is divided for classification and use. Classe de fermeture du couvert
Crown cover The ground area covered by the crowns of trees or woody vegetation as delimited by the vertical projection of crown perimeters and commonly expressed as a percentage of total ground area. Couvert
Cull Trees or logs or portions thereof that are of merchantable size but are rendered unmerchantable by defects. In nursery practice, a seedling that does not match the grade or specifications. Rebut
Cultivar A variety of plant cultivated on account of its favourable characteristics for horticulture, forestry or agriculture. Cultivars
Deadwood Timber produced from dead standing trees. More commonly, timber in dead standing trees. Bois mort
Decay Decomposition of wood caused by micro-organisms, mostly fungi. The wood generally becomes soft and crumbly, loses density and changes colour. Carie
Deciduous forest Subarea of the northern temperate zone, which is characterized mainly by sugar maple-dominated deciduous forests. This is the subarea with the greatest floristic richness. Forêt décidue
Deciduous species Trees that lose their leaves in the fall, such as birch, maple and basswood, are deciduous species. “Deciduous” means falling off or shed seasonally. Espèce arborescente décidue
Decline Disease that is characterized by a progressive decline in a tree’s health and in its growth and that may kill it. While the causes of this phenomenon are not known, it is generally believed that a combination of factors is to blame: pollution, soil acidification, drought, freeze-thaw action, etc. Dépérissement
Decurrent Refers to gills, folds, tubes or teeth that run down the stem of fungi. Décurrent
Deeply notched leaf Leaf that has deep sinuses cut into its outer edge. Feuille fortement découpée
Defoliation The removal of all or most of a plant’s leaves by natural disturbance agents (e.g., insects) or through the actions of humans (e.g., the application of herbicides). Défoliation
Dendrology The study of trees; tree identification. Dendrologie
Desiccation Process of becoming dried out. Dessiccation
Desirable plant species Species that contribute to management objectives. Espèces privilégiées
Diameter diameter at breast height (dbh) [diamètre à hauteur de poitrine (dhp)]: The stem diameter of a tree measured at breast height (1.3 m above ground level). Diamètre
Dibble planting Sowing seeds or setting out seedlings in rough holes made with a stick or peg. Also termed dibbling if done with a specially adapted tool such as a dibble. Plantation au bâton
Dipping The immersion of seedling roots in a solution or water prior to planting. Trempage
Discoloration Change in the normal colour of wood following infection by a micro-organism. Coloration
Disease Alteration of the normal functions of a whole plant or part of it, caused by a living or dead agent. The main agents involved in the initiation of disease are pollution, animals, fungi and other plants. Maladie
Disease Harmful deviation from normal functioning of physiological processes, generally pathogenic or environmental in origin. Maladie
Dominance potential The relative ability of a tree or plant species to dominate a forest ecosystem, given an opportunity equal to that of its associates. Potentiel de dominance
Drupe Fleshy fruit with a central hard core. Drupe
Ecosystem The sum of the plants, animals, environmental influences, and their interactions within a particular habitat. Écosystème
Ecotype A race (provenance) adapted to the selective action of a particular environment. Ecotypes are described in terms of the primary environmental influence, e.g., climatic or edaphic. Écotype
Edge habitat A loosely defined type of habitat that occurs at the boundary between two different habitat types. Typically, edge habitats share characteristics with both adjacent habitat types and have particular transitional characteristics that are important to wildlife. Habitat de lisière
Effective seedling Any seedling, whether natural or planted, that has survived in reasonable vigor for some arbitrary time and is so sited that it should make an effective contribution to the crop. Semis établi
Elongated leaf Leaf that is a lot longer than it is wide. Feuille allongée
Emergent A tree whose crown at maturity projects well above the level of the highest canopy. Émergent
Endangered species Species that are threatened with imminent extinction; includes species whose numbers or habitats have been reduced to critical levels. Espèce en voie de disparition
Enzyme A protein produced by a living organism and that speeds up a specific biochemical reaction. Enzymes are necessary to make almost all processes occurring in cells fast enough to sustain life. Enzyme
Epicormic shoot syn. sprout A shoot arising from a dormant or adventitious bud on the stem or branch of a woody plant. Pousse adventive
Epidermis Tissue covering the aerial portions of a plant. Épiderme
Establishment The process of developing a crop to the stage at which the young trees may be considered established, i.e., safe from juvenile mortality and no longer in need of special protection or special tending, but only routine cleaning and thinning. Établissement
Eugenic Favorable to the genetic quality of a population. cf. dysgenic. Eugénique
Exotic An introduced, non-native tree species. Exotique
Extirpated species Refers to the local extinction of a species that is no longer found in a locality or country, but exists elsewhere in the world. Espèce disparue
Female flower Part of the plant bearing the female sexual organ (pistil). Fleur femelle
Fertilization The union of the nucleus and other cellular constituents of a male gamete (sperm, pollen grain) with those of the female gamete (ovum, egg cell) to form a zygote from which may develop a new organism. Fécondation
Fibre (wood) A material in which the wood is reduced to predominantly individual fibres by mechanical or chemical means, or a combination of the two. Virgin fibre is derived from trees not previously processed into paper; recycled fibre has been reclaimed from a previous product such as old newsprint and reprocessed and incorporated into a new product. Fibre (ligneuse)
Field germination Generally, measure of the percentage, by number, of seeds in a given sample that germinate and produce a seedling, irrespective of subsequent seedling survival. Germination au champ
Filiform (threadliked) Thread-like. Filiforme
Filler A tree or species of inferior value, retained in thinning or cleaning, in the absence of any better. Remplissage (arbre de)
Flower The reproductive structure of a tree or other plant consisting of the male and/or female parts. Fleur
Foliage All the leaves of a tree. Feuillage
Forest Ecology: Generally, an ecosystem characterized by a more or less dense and extensive tree cover. More particularly, a plant community predominantly of trees and other woody vegetation, growing more or less closely together. Forêt
Forest Ecosystem that generally covers a large area and is composed of woody vegetation dominated by trees growing in a relatively dense pattern. Forêt
Forest land Land primarily intended for growing, or currently supporting, forest. It includes land not now forested (for example, clearcut lands and northern lands that are forested but not intended for any commercial forestry use) and plantations. Terres forestières
Forest regions classification A process of delineating large geographic areas according to landform and climate, associated with broad variations in overall forest composition. Classification des régions forestières
Forest sector The forest sector includes governments, conservation and environmental groups, woodlot owners, Aboriginals, urban forestry interests, lumber and pulp and paper producers and value-added industries, forest-reliant communities, the recreation and tourism industries, and other sectors of the economy (including the energy, chemical, and pharmaceutical industries) that derive wealth and well-being from forest resources. Secteur forestier
Forest site classification Grouping of forest sites using either the composition or the productivity of the vegetation as well as soil and topographic position. Classification de station forestière
Forest tree breeding The genetic manipulation of trees, usually involving selection, testing, and controlled mating, to solve some specific problem or to produce a specially desired product. Amélioration génétique des arbres forestiers
Forest tree species Group of individuals that possess common characteristics and are capable of producing fertile progeny Essences forestières
Forested tundra Subarea of the vast boreal zone characterized by a mosaic of stands of variable density and by tundra consisting mainly of shrubs and lichens. This plant formation is located at the tree line, and marks the division between the boreal zone and the arctic zone. Toundra forestière
Forestry Generally, a profession embracing the science, business, and art of creating, conserving, and managing forests and forest lands for the continuing use of their resources, material or other. Foresterie
Form General shape of a tree. Port
Fruit Reproductive organ of plants that results from fertilization of the flower and contains the seeds. Fruit
Fruit body A reproductive structure on or in which spores of a fungus are produced. Fructification
Fuel plantation syn. fuelwood plantation Setting out young trees to be hogged for burning. Plantation énergétique
Fuelwood Trees used for the production of firewood logs or other wood fuel. Bois de chauffage
Full seed Seed showing apparently complete embryo and endosperm or megagametophyte structures, irrespective of actual viability. Graine pleine
Functional food According to Health Canada, any food or food component demonstrated to have a compound that provides physiological benefits and/or reduces the risk of chronic disease beyond its basic nutritional functions. Functional foods are similar in appearance to or may be conventional foods and are consumed as part of a usual diet. Aliment fonctionnel
Fungicide Substance used to kill fungi. Fongicide
Fungicide Any agent used to kill or inhibit the growth of fungi and their spores. Fongicide
Fungicides Products that can inhibit the growth of fungi or kill them. Fungicides are used in agriculture and industrial plantation forestry to protect plants and trees from certain fungal diseases. Fongicides
Fusiform Spindle-shaped. Fusiforme
Gene flow The movement of alleles among interbreeding individuals belonging to different populations, by means of seed or pollen dispersal or the migration of individuals. Flux génique
Genetically modified organism (GMO) An organism that has had its DNA sequence altered through genetic engineering, a natural process, or the action of mutagens. Organisme génétiquement modifié (OGM)
Genotype An individual hereditary constitution derived from its parents and forming a unique combination of genes; sometimes referring to trees having similar genetic constitutions with regard to certain common, identifiable genetic characteristics. Génotype
Germination test A test made to determine the viability of seeds, spores, or pollen grains in a given sample. Essai de germination
Germinative capacity The percentage of seeds, spores, or pollen grains in a given sample that actually germinate, irrespective of time. In any batch of seeds, the percentage that is pure (of the species required) multiplied by the germinative capacity. Faculté germinative
Germinative energy The percentage of seeds, spores, or pollen grains in a given sample germinating within a given period e.g., 7 or 14 days, under optimum or stated conditions. Vigueur germinative
Glabrous Lacking hairs or down. Glabre
Greenhouse gas sinks Any process, activity or mechanism that removes greenhouse gases or their precursors from the atmosphere. The principal natural mechanism is photosynthesis. Puits de gaz à effet de serre
Greenhouse gas source Any process or activity (for example, forest fires or conversion of forest land to agricultural or urban uses) that releases greenhouse gases or precursors of those gases into the atmosphere. As trees and forest products decompose or burn, they release carbon in the form of carbon dioxide. Source de gaz à effet de serre
Group planting Setting out young trees in groups. Plantation par bouquets
Gymnosperm See conifer. Gymnosperme
Habitat The environment in which a population or individual lives; includes not only the place where a species is found, but also the particular characteristics of the place (for example, climate or the availability of suitable food and shelter) that make it especially well suited to meet the life cycle needs of that species. Habitat
Hard seed Seed having coats that resist cracking or breaking and may be more or less impermeable to water. Graine dure
Hard snag A snag composed primarily of sound wood, generally merchantable. Chicot dur
Hardening off Preparing seedlings or rooted cuttings for planting by gradually reducing water, nutrients, or day length, or by increasing light intensity and thus inducing changes in shoots that make them more resistant to exposure to full sunlight. Endurcissement
Hardwood(s) (broad-leaved trees) Trees whose leaves are not persistent and fall off at the end of a defined growing season or during a period of temperature or moisture stress. This is the predominant tree type in deciduous forests. Also refers to the wood produced by these trees. Feuillus (arbres à feuilles caduques)
Herbicide tolerant Capable of surviving and recovering from the application of herbicides. Tolérant aux herbicides
Heritage forest A forest managed to harvest forest products and to sustain the natural system, including its bioproductivity, biotic and abiotic diversity. Modern technology, equipment and methods may be used to harvest, restock and tend the forest, with an emphasis on natural restocking, supplemented with artificial restocking of appropriate endemic species. Forêt patrimoniale
High forest Crops and stands of trees, generally of seedling origin, that normally develop a high closed canopy. A term originally used to differentiate the natural, essentially seedling forest of long rotation from the artificial. Futaie
High-forest-with-reserves system An accessory system in which selected trees of the old crop, scattered or in groups, are retained after regeneration is completed, for the whole or a part of the next rotation. Futaie avec sur-réserves
Hole planting Setting plants in loosened soil replaced in or brought to a dug hole or pit. Roots separated on either side of a wedge or saddle of earth left in situ when the hole was dug is termed saddle planting. Plantation sur potets
Host Organism harbouring a parasite. Hôte
Hybrid Plant obtained by crossing two genetically dissimilar parent plants. Hybride
Hybrid The offspring of genetically different parents (usually refers to crosses between two species). Hybride
Hybridization Sexual reproduction using genetically distinct parents, that is, belonging to different populations, varieties, or species. Hybridation
Immature In even-aged management, those trees or stands that have grown past the regeneration stage but are not yet mature. In uneven-aged management, established trees too young for commercial harvest. Jeune
Impeder An individual of any value actually impeding the development of another individual of higher grade. Inhibiteur
Increment The increase in diameter, basal area, height, volume, quality, or value of individual trees or stands during a given period. (5) Accroissement
Industrial plantation forestry Tree cultivation using methods of intensive silviculture: plantations made up of genetically improved stock, fertilization, drainage, phytosanitary treatments, release of higher quality stems, etc. Ligniculture
Intensive silviculture 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. Sylviculture intensive
Interplanting Planting young trees among existing natural regeneration or previously planted trees of similar age. Plantation intercalaire
Inventory (forest) A survey of a forest area to determine data such as area, condition, timber, volume and species for a specific purpose, such as planning, purchasing, evaluating, managing or harvesting. Inventaire forestier
J-root A root, especially a seedling tap root, having a sharp bend greater than 90, shaped like a J. Frequently introduced by inappropriate planting. Racine en J
Juices Organic liquid contained in certain plant and animal structures, eg, plant sap. Suc
Juvenile wood An inner layer of xylem surrounding the pith, in which the cells are smaller and/or less structurally developed than those of the outer xylem. The period during which it is formed is termed the juvenile period; it varies between individuals Bois de jeunesse
L-notch planting Special form of slit planting involving two slits at right angles with the seedling placed at the apex of the L. plantation avec fentes en L
Lammas shoots Extra leader growth extension late in the growing season. Pousse d’été
Layering The rooting of an undetached branch, lying on or partially buried in the soil, or surrounded by moist fiber sealed in a plastic wrap (air layering), termed a layer, which is capable of independent growth after separation from the parent plan. Marcottage
Layering method Regeneration of a forest stand using layerings. Méthode du marcottage
Leaf Organ in plants that has various forms (needles, scales, etc.) and that carries on photosynthesis, producing energy for life. Feuille
Leaf-fall Normal shedding of leaves in the fall. Défeuillaison
Leave tree A tree (marked to be) left standing in an area where other trees are felled. Arbre marqué en réserve
Lifting the canopy Removing the lower constituents of a canopy, e.g., the lowest undergrowth, shrubs, and small trees in a multistoried forest, mainly to assist the main crop, particularly for regeneration, but also for readier access. Élagage de dégagement
Light framing lumber Lumber that is 5 to 10 cm thick and 5 to 10 cm wide. It is used in a large variety of general construction applications. Bois à charpente légère
Lignin Main component of wood. Lignine
Lignin A complex and relatively hydrophobic biopolymer present in the secondary cell walls of vascular plants—and particularly abundant in wood—that gives rigidity to plant stems and allows them to conduct water efficiently. Lignine
Live-crown ratio A rough but convenient index of the ability of a tree's crown to nourish the remaining part of the tree; it is the percentage of length of stem having living branches. L-notch planting [plantation avec fentes en L. Taux de cime vivante
Living modified organism (LMO) As defined in the Cartagena Protocol on Biosafety, a living organism that possesses a novel combination of genetic material obtained through the use of modern biotechnology. Organisme vivant modifié (OVM)
Lobe Large division of a leaf. Lobe
Logging damage General term comprising wounds resulting from cutting, breakage, or crushing of trees that resulted from the felling and the removal of trees designated for cutting. May also include scoring of site and soil leading to exposure Dommage de coupe
Lop and top The branches and tops cut from a tree, generally once felled or fallen. Résidus d’ébranchage-façonnage
Lumber Wood processed in a sawmill. Bois d'œuvre
Main crop In regular crops or stands, that portion of the growing stock retained after an intermediate cutting. Peuplement principal
Male flower Part of the plant bearing the male sexual organ (stamen). Fleur mâle
Mammal Four-legged vertebrate of the class Mammalia, characterized by females that produce milk with which to feed their young. Mammifère
Mature In even-aged management, those trees or stands that are sufficiently developed to be harvestable and that are at or near rotation age (includes overmature trees and stands for which an overmature class has not been recognized. Mûr
Maturity class Trees or stands grouped according to their stage of development, from establishment to suitability for harvest. A maturity class may comprise one or more age classes. Classe de maturité
Mechanical planting Setting out young trees by means of a machine specially designed for this operation. Plantation mécanique
Merchantable Of a tree or stand that has attained sufficient size, quality, and/or volume to make it suitable for harvesting. Does not imply accessibility, economic or otherwise. Marchand
Merchantable snag A snag that is of sufficient quality and/or volume to make it suitable for harvesting. Chicot marchand
Micropropagation In vitro asexual reproduction of a plant from a fragment of plant tissue. This technique creates multiple copies of progeny that are genetically identical to the parent (clones). Micropropagation
Microsite The ultimate unit of the habitat, i.e., the specific spot occupied by an individual organism. By extension, the more or less specialized relationships existing between an organism and its environment. Niche (écologique)
Mist forest A forest of high elevation that occurs along the foggy windward shores of continents and islands. Forêt de brouillard
Mixed forest Subarea of the northern temperate zone, which is dominated by mixed forests encompassing both coniferous boreal species and more southerly deciduous species. Forêt mélangée
Mixed stand A stand composed of two or more species in which less than 80% of trees in the main crown canopy are of a single species. The threshold in Manitoba and New Brunswick is 75%. cf. pure stand Mélangé
Mixedwoods Trees belonging to either of the botanical groups Gymnospermae or Angiospermae that are substantially intermingled in stands. Peuplement mixte
Morphology Form and structure of living organisms. Morphologie
Mortality Death or destruction of forest trees as result of competition, disease, insect damage, drought, wind, fire, old age, and other factors, excluding harvesting. Mortalité
Mound planting Setting out young trees on raised microsites. Plantation sur butte
Mutation A change to the DNA sequence of a gene or chromosome; may be expressed or unexpressed by the cell. If a mutation occurs in a gene, it changes the structure, function, or expression of the protein produced. Mutation
Nanocrystalline cellulose Nano structures made from pure cellulose used in coating, papermaking, drug delivery, biocide dispersion, composite products, etc. Cellulose nanocristalline
National forest strategy An overarching national vision and framework for Canada’s forests developed by the Council of Canadian Forest Ministers. The first strategy appeared in 1981. Stratégie nationale sur la forêt
Native (indigenous) A species that occurs naturally in an area. Indigène
Natural regeneration Renewal of a tree crop by natural seeding, sprouting, suckering, or layering. Régénération naturelle
Necrosis Alteration of tissues caused by the death of cells. Nécrose
Nectar Sweet liquid produced by special glands in flowers (called nectaries) to attract insects. Nectar
Needle Long, narrow reduced leaf found in conifers. Aiguille
Needle cast Reddening or browning of needles, sometimes leading to premature shedding of foliage. Rouge
Needles borne in clusters (or bundles) Group of needles joined together at the base Aiguille en faisceau
Nest planting Setting out a number of seedlings or seeds close together in a prepared hole, pit, or spot. Plantation en nids
Niche environment The unique environment used to sustain the existence of an organism or species. Niche écologique
Nodule Globulose or elongated mass formed by certain fungi or a mixture of plant and fungal tissues. Nodule
Non-commercial tree species A tree species for which there is currently no market. Essence forestière non commerciale
Non-timber value A value within the forest other than timber that includes, but is not limited to, biological diversity, fisheries, wildlife, minerals, water quality and quantity, recreation and tourism, cultural heritage values, and wilderness and aesthetic values. Valeurs non ligneuses
Nurse log A dead or downed log that fosters tree seedlings by protecting them from such environmental factors as wind, insolation, or frost, or by providing appropriate soil and microclimate. Grume-abri
Nutlet Fruit, small nut. Nucule
Occlusion The process of healing of cut branch stubs by the cambium of the surrounding stem surface. Occlusion
Old-growth forest An old growth forest differs significantly from younger stands in structure, ecological function and species composition with respect to canopy closure, age class structure, accumulation of woody debris and the presence of species and functional processes that are representative of the potential natural community. Forêt anciennne / vieille forêt
Ombrophilous Able to thrive in areas of abundant rainfall. Ombrophile
Open forest Proposed name for the natural forest commonly found in northern Canada. This forest is a mixture of wetlands and small trees, occasionally interspersed with highly productive forests. Forêts claires
Order Taxonomic level between Class and Family. In insects, for example, classification in orders is based primarily on wing shape. Ordre
Organ Group of tissues organized to perform a distinct function. Organe
Outplant A seedling, transplant, or cutting ready to be established on an area. Plant sur le terrain
Ovoid Egg shaped. Ovoïde
Parthenogenesis Form of reproduction in which an organism develops from an unfertilized egg. Parthénogenèse
Particle gun transformation See biolistics. Transformation par canon à particules
Patch logging A modification of the clearcutting system developed in the Pacific Coast region of North America, whereby patches of about 5 to 200 ha are logged as single units, separated for as long as practicable. Exploitation par blocs
Pathogen A microscopic organism or virus directly capable of causing disease. see thinning: precommercial. Pathogène
Pathogenic A parasitic organism directly capable of causing disease. Pathogène
Pathology The study of disease. Pathologie
Pathology Study of diseases and the effects they have on plants. Pathologie
Persistent foliage Characteristic of evergreen trees, that is, trees that do not shed their leaves in the fall. Feuillage persistant
Pest Organism that causes serious damage to plants or foodstuffs. Ravageur
Pest resistance A heritable trait that enables an organism (e.g., a tree) to be less damaged by pests compared to its non-resistant relatives. Résistance aux ravageurs
Phenolic compound A highly complex organic compound that exists in every plant in various mixes, ratios and concentrations. Phenols include, for example, many plant pigments. Composés phénoliques
Phenology The study of timing of periodic phenomena, such as flowering, growth initiation, growth cessation, etc., especially as related to seasonal changes in temperature, photoperiod, etc. Phénologie
Phenotype An organism as observed, i.e., as judged by its visually perceptible characters resulting from the interaction of its genotype with the environment. Identical phenotypes do not necessarily breed alike. Phénotype
Phloem The part of the tree that is produced through the growth of cambium cells in an outward direction. It may also be called secondary phloem. The sap produced by the leaves travels through the phloem tissue downwards in the tree. Compared with the xylem (wood) the phloem occupies a very small part of the tree. Phloème
Photosynthesis Formation of carbohydrates in the chlorophyll-containing tissues of plants exposed to light. Photosynthèse
Phyllum Taxonomic level between Kingdom and Class. Eg, phyllum Arthropoda composed of organisms with a segmented body. The body wall is more or less hardened and forms an exoskeleton. Embranchement
Pioneer species Species that are the first to colonize a new site or a new ecosystem. They are generally shade intolerant and need a lot of sunlight in order to grow. Poplars and birches are pioneer species. Espèce pionnière
Pioneer species A species adapted to early stages of natural forest succession or growth on newly available sites. Essences transitoires
Pit planting Setting out young trees in small depressions, natural or excavated, with a view to collecting and conserving moisture. Plantation sur trous
Plant with novel traits (PNT) In accordance with the Seeds Regulations, Part V related to the Seeds Act administered by the Canadian Food Inspection Agency, a plant variety possessing a characteristic that is intentionally selected or created through a specific genetic change and is either not previously associated with a distinct and stable population of the plant species in Canada or expressed outside the normal range of a similar existing characteristic in the plant species. Végétal à caractères nouveaux (VCN)
Plantation forest Forest stands established by planting and/or seeding in the process of afforestation or reforestation which are either of introduced species (all planted stands) or intensively managed stands of indigenous species, which meet all the following criteria: one or two species at plantation, even age class, regular spacing. Plantation forestière
Plantation forestry Application of forestry principles to an artificial crop or stand. Foresterie de plantation
Planting Establishing a forest by setting out seedlings, transplants, or cuttings in an area. Plantation
Planting spot The exact spot where a young tree has been set out. Emplacement des semis
Plug transplant A small container seedling which is to be planted and raised as a bare-root seedling. Plant fiche
Plus stand A stand containing a preponderance of good phenotypes, but not necessarily plus trees. Peuplement plus
Plus tree A phenotype judged (but not proved by testing) to be unusually superior in some quality or qualities. Arbre plus
Pocket of infection Area in a stand or plantation where a disease originated. Foyers d'infection
Pole A tree between a sapling and small sawtimber size. Size varies by region, e.g., for boreal and eastern forests 12-20 cm dbh. Perche
Pollarding Cutting back the crown of a tree (removal of dead, diseased or unwanted branches). Émondage
Pollination Transfer of pollen from the anther of a flower to the stigma of a flower of the same species, resulting in fertilization. Pollinisation
Population A group that includes all possible members of a species in a territory at a given time. Population
Pot planting Setting out young trees in pot-shaped receptacles having a closed or only perforated end and made of various materials, in which they have been raised from seed or to which they have been transferred from the seed bed. Plantation en pot
Predominant A tree whose crown has grown above the general level of the upper canopy. Prédominant
Pregermination The germination of seed, generally to the stage when the radicle is just emerging, before sowing in the field or nursery. Germination physiologique
Principal species The species to which the silviculture of a mixed forest is primarily directed, either for its (or their) economic or protective value. Essences principales
Protection forest All forest land managed primarily to exert beneficial influence on soil, water, landscape, or for any other purpose when production of merchantable timber, if any, is incidental. Forêt de protection
Provenance 1. The geographical area and environment to which the parent trees, etc., are native and within which their genetic constitution has been developed through natural selection. 2. The geographical source, i.e., place of origin. Provenance
Pruning 1. The removal of live branches from standing trees, termed green pruning; or of dead branches, dry pruning. 2. Removal of live or dead branches from ground level to as high as a person's reach (2.0-2.5 m) in a young stand. Élagage
Pruning Removal of branches from a tree, particularly beneath the crown. Élagage
Quincunx planting Setting out four young trees to form the corners of a square with a fifth tree at its center. Plantation en quinconces
Race A population that exists within a species and exhibits genetic characteristics distinct from those of the other populations. It is usually an interbreeding unit. Race
Ramicorns Abnormally large branches that project at sharp acute angles from the bole and are persistent (often associated with previous weevil attack). Ramicorne
Regeneration Renewal of a forest crop by natural, artificial, or vegetative (regrowth) means. Also the new crop so obtained. The new crop is generally less than 1.3 m high. Régénération
Regeneration class The area, and the young trees in the area, being managed during the regeneration interval in the shelterwood silvicultural system. In this interval, old and young trees occupy the same area, the young being protected by the old. Classe de régénération
Regeneration interval The period between the seed cutting and the final cutting on a particular area under one of the shelterwood systems. Durée de régénération
Regrowth A term used in reference to coppice, as well as recovery of vegetation from treatment designed to impede or control its growth. Recrû
Resilience The capacity of a community or ecosystem to maintain or regain normal function and development following disturbance. Résilience
Resin blister Swelling containing resin, a sticky gum-like substance. Vésicule de résine
Resinous See conifer. Résineux
Ridge planting Setting out young trees on a long, narrow crest of excavated soil, generally on a slice thrown up by a plough. Plantation sur bourrelet
Riparian forest At a large scale, it is the band of forest that has a significant influence on a stream ecosystem or is significantly affected by the stream. At a smaller scale, it is the forest at the immediate water’s edge, where some specialized plants and animals form a distinct community. Forêt riveraine
Root Part of the tree that anchors it and absorbs nutrients from the soil. Racine
Root collar Transition point between the roots and the trunk. Collet
Root pruning The act of reducing one or more roots considered to be superfluous, usually at some stage before outplanting, in order to improve the shape and size of a root system. Élagage des racines
Root puddling The act or treatment of immersing, sometimes several times in close succession, the root systems of bare-root planting stock in a clay slurry with the aim of improving outplant performance. Pralinage des racines
Root rot Decomposition of the woody tissue in roots causing the death of the cambium or bark of the roots, thus girdling the trees at the root collar and causing their death. Pourridié
Root stripping 1. The accidental removal of roots during lifting, handling, and planting, especially when caused by improper practices. 2. The removal of bark from roots. Dépouillement des racines
Root sucker See sucker Drageon racinaire
Root wad The mass of roots, soil and rocks that remains intact when a tree, shrub, or stump is uprooted. Motte racinaire
Root-to-shoot ratio The total mass or volume of the plant root system divided by the total mass or volume of the shoot system, usually on an oven-dry basis. Rapport système racinaire/système foliacé
Round leaf Leaf of variable shape whose length is nearly the same as its width. Feuille ronde
Roundwood Sections of tree stems, with or without bark. May include logs, bolts, posts and pilings. Bois ronds
Rust Disease caused by a fungus that is parasitic on higher plants and may go through five different developmental stages, usually involving hosts. Following infection, orange pustules appear, possibly followed by premature shedding of foliage, witches' brooms or cankers. Rouille
Samara A winged, one-seeded fruit. Samare
Sapling A general term for a young tree no longer a seedling but not yet a pole, about 1-2 m high and 2-4 cm in dbh, typically growing vigorously and without dead bark or more than an occasional dead branch. Gaule
Sawtimber Trees that will yield logs suitable in size and quality for the production of lumber. Bois de sciage
Scale (Botany) One of the small overlapping plate-like parts that make up the modified leaf of cedars. (Entomology) Tiny, overlapping plates covering the wings of butterflies. Écaille
Science (forest) The study of the material universe or physical reality in order to understand it. This is done by making observations and collecting data about natural events and conditions, then organizing and explaining them with hypotheses, theories, models, laws and principles. Science forestière
Second growth forest The forest growth that has developed (naturally or artificially) following the removal of the original forest. Forêt de seconde venue
Secondary species A species of inferior quality and/or size, and of lesser silvicultural value, associated with the principal species. cf. accessory species Essences secondaires
Secondary succession Process whereby one stand or plant community supplants another; it is triggered by a major disturbance in a forest ecosystem. Successions secondaires
Seed Fertilized ovule that contains an embryo and has the capacity to produce a new individual. Graine
Seed tree A tree selected, and often reserved, for seed collection or provision of seed for natural regeneration. Semencier
Seeding aerial [ensemencement aérien]: Broadcast seeding of seeds or seed pellets from aircraft. broadcast [ensemencement à la volée]: The sowing of seeds more or less evenly over a whole area. Ensemencement
Seedling Young plant that has grown from a seed. Semis
Selection Choosing individuals with desired qualities to serve as parents for the next generation. Sélection
Selection pressure Environmental influences on an organism that determine its likelihood of being preferentially selected among its co-habitants, that is, having a better survival and/or reproduction. Pression sélective
Serotinous Coming late; particularly applied to plant species or individuals with cones that remain on the tree without opening for one or more years (e.g., Pinus contorta and Pinus banksiana). Marcescent
Sexual reproduction Reproduction that involves the fusion of genetic material from two distinct entities. Reproduction sexuée
Shade system An agroforestry system involving the planting of trees or shrubs whose canopy provides the appropriate level of shade to grow shade-requiring (perennial) crops. Système de production sous couvert forestier
Shoot pruning Cutting away undesirable shoots to favor survival and growth of selected shoots. Élagage des rejets
Shortwood harvesting Felling and cross-cutting on the spot, i.e. transporting the logs from the cutting, not the whole bole or tree. Exploitation en bois courts
Shrub A perennial plant differing from a perennial herb in its persistent and woody stem(s), and less definitely from a tree in its lower stature and the general absence of a well-defined main stem. Arbrisseau
Silvics The study of the life history and general characteristics of forest trees and stands, with particular reference to locality factors as a basis of silviculture. Écologie forestière
Silvicultural efficacity The capacity of a herbicide indirectly to promote positive growth responses in crop trees. Efficacité sylvicole
Silviculture The theory and practice of controlling the establishment, composition, growth, and quality of forest stands to achieve the objectives of management. Sylviculture
Silviculture Practices aimed at ensuring wise harvesting of forest resources : conservation, regeneration, reforestation, cutting, etc. Sylviculture
Site class Any interval into which the site index range is divided for purposes of classification and use. Classe de station
Site classification Application of analytical techniques based on macroclimate, soil, land form, and vegetation, to predict yield. Classification de station
Site factor An ecological term referring to a physical or biological parameter used to describe and distinguish sites. Facteur de station
Size classes Ranges in tree sizes representing stages in the development of a tree or stand. Classe de dimension
Slit planting Prying open a cut made by a spade, mattock, or planting bar (termed bar planting), inserting a young tree, then closing the cut on the latter by pressure. Plantation en fente
Snag A standing dead tree from which the leaves and most of the branches have fallen. Chicot
Soft snag A snag composed primarily of wood in advanced stages of decay and deterioration, particularly in the sapwood portion. Chicot pourri
Sowing brick A prepared, sometimes fertilized, block or ball of loam, peat, plastic foam, etc., into which one or more seeds are pressed, so that, on planting out, the emergent seedling can have a better start in an unfavorable environment. Motte à semis
Spacing The distance between trees in a plantation, a thinned stand, or a natural stand. v: see thinning: spacing Espacement
Species Group of individuals that possess common characteristics and are capable of producing fertile progeny Espèce
SPF (spruce-pine-fir) Canadian woods of similar characteristics that are grouped as one lumber type for production and marketing purposes. EPS (épinette-pin-sapin)
Spore Cell or group of cells capable of producing a new organism. Spore
Spore print Deposit of spores released into the air or onto a surface when a fungus cap is placed gills downwards. Sporée
Spot Circular or nearly circular lesions that appear on a leaf blade. They have a central zone of necrotic (dead, brown) tissue colonized by a pathogen; this zone is surrounded by healthy, coloured tissue. Tache
Spot planting Setting out young trees in small, prepared patches. Plantation sur placeaux
Sprout Generally, any shoot arising from a plant. More particularly, a shoot arising from the base of a plant, from the stool (stool shoot) or from the root (sucker). Rejet de taillis
Stand A community of trees possessing sufficient uniformity in composition, age, arrangement, or condition to be distinguishable from the forest or other growth on adjoining areas, thus forming a silvicultural or management entity. Peuplement
Stand condition The descriptive measurement of a stand by the criteria of composition, health, age, size, volume, or spatial arrangement. État d’un peuplement
Standard A tree selected to remain standing, after the rest of the stand has been felled over a younger or a new crop, for some special purpose, e.g., shelter, seeding, production of a special quality or size of timber. Réserve
Sterile tree Tree incapable of reproducing sexually. Arbre stérile
Stocked forest land Land supporting tree growth. In this context, tree growth includes seedlings and saplings. Terrain forestier boisé
Stoma Microscopic opening, many of which are found on the underside of plant leaves, permitting transpiration and gaseous exchanges (pl. stomata). Stomate
Stool 1. Silviculture: A living stump capable of producing sprouts or shoots. 2. Propagation: A living stump maintained to produce cuttings, layers, etc. Souche-mère
Storied high forest A crop of trees in which the canopy can be differentiated into one or more layers, the dominant species in natural forest generally differing in each layer. Futaie pluriétagée
Stratification The storage of seeds under defined conditions of environment (temperature, moisture, gas exchange, medium, etc.) for specified periods in order to overcome passive or active inhibition of germination. Stratification
Strip cropping Crop planting in which strips of heavy-rooted plants are alternated with loose-rooted plants which serve as barriers to wind and water erosion. Plantation en lisières
Strip planting Setting trees, generally in two or more parallel lines, in a long narrow area of land that has been wholly or partially cleared. Plantation en bandes
Structural lumber Wood suitable for framing and load-bearing structures essentially by virtue of its strength. Bois de charpente
Structure The distribution of trees in a stand or group by age, size, or crown classes (e.g., all-aged, even-aged, uneven-aged, regular, and irregular structures). Structure
Stub The broken or cut base of a branch projecting from a tree stem. Chicot
Stump Part of trunk with roots remaining after a tree has been cut down. Souche
Stunted Characteristic of a plant that has not developed normally and resembles a bonsai. Rabougris
Succession The gradual supplanting of one community of plants by another, the sequence of communities being termed a sere and each stage seral. Succession
Sucker A shoot or tree originating from adventitious buds on roots. Drageon
Sun system An agroforestry system involving the planting of trees or shrubs with agricultural crops or forest-derived crops that require full sun. As the trees/shrubs grow, the canopy closes, and the level of shade increases, a sun system may become a shade system or another agroforestry system. (See also intercropping.) Système de production à découvert
Symbiotic association The living together in intimate association of two dissimilar organisms, so that the cohabitation is mutually beneficial. Association symbiotique
T-notching see slit planting Bêchage en T
Taiga Subarea of the extensive boreal zone characterized by open coniferous forest with lichens. Taïga
Taungya plantation The raising of a forest crop in conjunction with a temporary agricultural crop. Plantation en taungya
Taxonomy Set of rules governing the classification and naming of species. Taxinomie
Temperate forest One of three main forest zones in the world (see also boreal forest, tropical forest). The woodland of rather mild climatic areas; composed mainly of deciduous trees. Forêt tempérée
Thicket A dense growth of small trees or bushes. Fourré
Threatened species A species that is likely to become endangered in Canada if the factors affecting its vulnerability are not reversed. Espèce menacée
Timber A general term for forest crops and stands, and sometimes for any lesser aggregation of such trees. Bois
Tolerance The ability of an organism or biological process to subsist under a given set of environmental conditions. The range of these under which it can subsist, representing its limits of tolerance, is termed its ecological amplitude. Tolérance
Trainer A tree beneath the main canopy which by its shading and/or abrasive action hastens the natural pruning or improves the form of some other tree. Dominé élagueur
Trait A distinguishable characteristic of an organism. Caractère
Transformation Transfer of foreign DNA into the cell of an organism to change its genetic makeup. This is a natural process for many bacteria. Transformation
Transgenic Genetically engineered to contain DNA from an external source, such as another species or a different variety. Many transgenic plants are more herbicide tolerant, are resistant to insect or viral pests, or produce modified versions of fruit or flowers. Transgénique
Transplant A seedling that has been replanted one or more times in a nursery to improve its size and growth potential characteristics. Also a tree that is moved from one place to another. Plant repiqué
Transplanting plough A plough used in the nursery to open trench for the roots of plants being lined out, while simultaneously backfilling it. Charrue planteuse
Tree class Any class into which the trees forming a crop or stand may be divided for a variety of purposes. Classe d’arbre
Tree surgery The care and repair of trees valued for amenity. Chirurgie des arbres
Trench planting Setting out young trees in a shallow trench or a continuous slit. Plantation en sillon
Trunk Part of the tree that is generally straight and vertical, located between the root collar and the branches (crown). Tronc
Tube planting Setting out young trees in narrow, open-ended cylinders of various materials, in which they have been raised from seed or into which they have been transplanted. Plantation de semis en tube
Tubular Tube-shaped. Tubulaire
Twig The smallest division of a branch which bears the annual shoot. Rameau
Underplant Young trees used for underplanting. Plant de sous-étage
Underplanting Planting young trees under the canopy of an existing stand. Plantation en sous-étage
Understorey The lower level of vegetation in a forest. Usually formed by ground vegetation (mosses, herbs and lichens), herbs and shrubs. Sous-étage
Undesirable species Species that conflict with or do not contribute to the management objectives. Essences indésirables
Uneven-aged Of a forest, stand, or forest type in which intermingling trees differ markedly in age. The differences in age permitted in an uneven-aged stand are usually greater than 10-20 years. Inéquienne
Unmerchantable Of a tree or stand that has not attained sufficient size, quality, and/or volume to make it suitable for harvesting. Non marchand
Urban forest The trees, forests, and associated organisms that grow near buildings and in gardens, green spaces, parks, and golf courses located in village, town, suburban, and urban areas. Forêt urbaine
Variable-retention A silvicultural system that follows nature’s model by always retaining part of the forest after harvesting. Standing trees are left in a dispersed or aggregated form to meet objectives such as retaining old-growth structure, habitat protection and visual quality. Variable retention retains structural features (snags, large woody debris, live trees of varying sizes, canopy levels) as wildlife habitat. Rétention variable
Variety Specifically within forestry, any clone or product of breeding given a separate name. Variété
Variety Subdivision of species, a group of individuals that have common characteristics (example : The different varieties of apples). Variété
Vegetative propagation Reproduction by other than sexually produced seed. Includes grafting, budding, rooting of cuttings, and tissue and cell culture, including embryogenesis. Multiplication végétative
Venation Distribution of veins on the wings of an insect or on a leaf. Nervation
Vertical structure The structure formed by different layers of vegetation in a forest. Structure verticale
Vesicle Small, bladder-like structure. Vésicule
Viability Of a seed, spore, or pollen grain, its capacity to germinate and develop, under given conditions. Viabilité
Vigor class Assumption of the health of a tree based on observation of the foliage. Classe de vigueur
Viviparous Bringing forth living, fully formed individuals that are capable of feeding. Said of producing bulbils on young plants, instead of and in place of flowers. Vivipare
Volunteer growth Natural regeneration following site preparation and seeding or planting that could either supplement or completely obscure the trees being planted or seeded on the area. Régénération subséquente
Vulnerable species A species that is considered at risk because it exists in low numbers or in restricted ranges, due to loss of habitat or other factors. Espèce vulnérable
Weed tree Any tree of a species having little or no economic value on the site in question. Indésirable
Whip 1. A bare-root hardwood planting stock. 2. Any slender tree that the wind causes to lacerate the crowns of its neighbors. Fouet
Wildling syn.: wilding, wild seedling A naturally grown, in contrast to a nursery-raised, seedling, sometimes used in forest planting when nursery stock is scarce. Semis naturel
Wilt Drying out, loss of colour and shape of leaves, then twigs and branches, caused by a lack of water or the presence of toxins. Flétrissement
Wind lean Condition of trees having a leaning stem, result of partial uprooting or wind action. cf. windfirm Couché par le vent
Windfirm Of trees, able to withstand strong winds, i.e., to resist windthrow, windrocking, and major breakage. Such trees may not remain upright but show wind lean or wind bend or both. Stable au vent
Windrow planting Planting between the two lanes created in windrowing. Plantation sur entrandain
Witches' broom Excessive proliferation of twigs from one location on a branch or several locations close together. The twigs in a broom are erect and compacted. Balai de sorcière
Wolf tree A tree, generally overtopping and of poor form, that occupies more growing space than its commercial value warrants. Arbre loup
Wood A plant tissue composed essentially of lignified fibers of cellulose and hemicellulose. Wood is present in the stems of trees and shrubs where it ensures support and conducts water. (See also cellulose and lignin.) Bois
Woody tissue Plant tissue containing lignin, the main component of wood. Ligneux
Yearling A one-year-old seedling. Semis de l’année