Glossary

References used in developing the glossary

A B C D E F G H I J K L M

N O P Q R S T U V W X Y Z

 

Alliance (CNVC)
for upland vegetation that includes zonal vegetationan aggregation of Associations, with consistency in dominant and/or diagnostic species, describing regionally repeating vegetation patterns at the local to sub-regional scale. Alliances are created by grouping Associations that are ecologically “related” into more generalized ecological units (e.g., successionally related forest Associations on similar edaphic conditions can be aggregated into more generalized Alliances). For example, CA00035 Picea glaucaPinus contorta / Hylocomium splendens (White Spruce – Lodgepole Pine / Stairstep Moss). 
for azonal vegetation: a vegetation classification unit containing one or more associations and defined by a characteristic range of species composition, habitat conditions, physiognomy, and diagnostic species, typically at least one of which is found in the uppermost or dominant stratum of the vegetation. Alliances reflect regional to subregional climate, substrates, hydrology, moisture/ nutrient factors, and disturbance regimes.
The Alliance is the seventh (from the top) level in the CNVC hierarchy. For more information on the CNVC hierarchy, see The CNVC Hierarchy.
anthropogenic
see “soil parent material”.
ash
see “soil rooting zone substrate”.
aspect
the orientation of a slope face, expressed using a compass direction.
Association (CNVC)
a plant community type with consistency of species dominance and overall floristic composition, having a clearly interpretable ecological context in terms of site-scale climate, substrate and/or hydrology conditions, moisture/nutrient factors or disturbance regimes, as expressed by diagnostic indicator species. For example, CNVC00102 Picea glauca / Rosa acicularis / Hylocomium splendens (White Spruce / Prickly Rose / Stairstep Moss). The Association is the eighth (from the top) and most detailed level in the CNVC hierarchy. For more information on the CNVC hierarchy, see The CNVC Hierarchy.
azonal sites
sites where the primary ecological influences on vegetation reflect local topography and/or soil properties (e.g., wetlands); see “zonal sites”.
azonal vegetation
vegetation characteristic of azonal sites.
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bedrock
see “soil parent material”.
bog
an ombrotrophic peatland receiving water exclusively from precipitation and not influenced by groundwater; bogs can be treed or non-treed, but vegetation is characterized by Sphagnum spp. and ericaceous shrubs. See “fen”, “marsh”, “swamp”.
brown moss
a group of minerotrophic moss species that commonly occur together and are valuable classification indicators of richer, wetter habitat conditions. Species include Aulacomnium palustre, Tomenthypnum nitens, Scorpidium spp., Drepanocladus spp., and Campylium stellatum.
Brunisolic soil
in the Canadian System of Soil Classification, an order of soils whose horizons are developed sufficiently to exclude the soils from the Regosolic order but that lack the degrees or kinds of horizon development specified for soils of the other orders. These soils which occur under a wide variety of climatic and vegetative conditions all have Bm or Btj horizons.
bryophyte
a division of nonvascular land plants (Bryophyta), including mosses, liverworts, and hornworts; bryophytes lack vascular tissues for circulating liquids, and reproduce via spores.
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character species
a species with constancy class ≥ III that is clearly associated with only one particular vegetation type within a large geographic area.
Chernozemic soil
in the Canadian System of Soil Classification, an order of soils that have developed under xerophytic or mesophytic grasses and forbs, or under grassland-forest transition vegetation, in cool to cold subarid to subhumid climates. The soils have a dark-colored surface (Ah or Ahe or Ap) horizon and a B and/or C horizon of high base saturation. Chernozemic soils mainly occur in the Great Plains of west-central Canada.
clayey soil
see “soil rooting zone substrate”.
climax vegetation
stable, self-perpetuating vegetation that represents the final stage of succession under existing environmental conditions.
coarse loamy soil
see “soil rooting zone substrate”.
coarse sandy soil
see “soil rooting zone substrate”.
cold-deciduous
dropping leaves in the autumn.
colluvium
see “soil parent material”.
conifer
species that produces cones. Most conifer species in Canada are evergreen, but some (e.g., Larix spp.) are cold-deciduous; native conifer species in Canada have needle-like or scale-like leaves.
constancy
percentage of plots in which a species is found (e.g., a species found in 25 of 100 plots has a constancy of 25%); equivalent to “presence” and "frequency of occurrence".
constancy class
a class that groups a specific range of constancy values. In the CNVC, the constancy classes are:
I 1-20%
II 21-40%
III 41-60%
IV 61-80%
V 81-100%
constant species
a species of high constancy in a vegetation type; constancy class ≥ IV.
cover
the area of ground covered by plants of one or more species, usually expressed as a percentage.
cryomorphic
pertaining to plants having structural or functional adaptations to survive cold temperatures and resist frost damage (e.g., alpine creeping dwarf shrubs, krummholz).
Cryosolic soil
in the Canadian System of Soil Classification, an order of mineral or organic soils that have perennially frozen material within 1 m of the surface. The mean annual soil temperature is less than 0°C. These are the dominant soils of the zone of continuous permafrost in northern Canada, becoming less widespread in the zone of discontinuous permafrost further south. Their maximum development occurs in organic and poorly drained, fine textured materials. Vegetation varies from sparse plant cover in the high arctic, through tundra, to subarctic and northern boreal forests.
cryptogam
a plant that reproduces by means other than the production of seeds (e.g., spore-producing bryophytes and pteridophytes).
cryptogamic vegetation
see “physiognomy”.
cryptophyte
a plant whose buds or shoot apices remain below the ground or water surface during unfavourable seasons.
cultural vegetation
a plant community introduced and actively maintained by humans; no clear natural analogue is known for the species composition or vegetation structure (e.g., lawn).
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diagnostic species
any species or group of species whose relative constancy or abundance differentiates one vegetation type from another; these can include character, differential, constant, indicator or dominant species; in the CNVC, most diagnostic species are differential, constant, indicator or dominant species.
differential species
a species with constancy class ≥ III that because of its fidelity is clearly associated with a particular vegetation type within a large geographic area. The species may also be a differential species in another type that has a different diagnostic combination of species.
Division (CNVC/USNVC)
a combination of dominant and diagnostic growth forms and a broad set of diagnostic plant species that reflect biogeographic differences in composition and continental differences in mesoclimate, geology, substrates, hydrology, and disturbance regimes. For example, D014 North American Boreal Forest & Woodland. The Division is the fourth (from the top) level in the CNVC / USNVC hierarchy. For more information on the CNVC hierarchy, see The CNVC Hierarchy.
dominance
the extent to which a constant species predominates in a vegetation type because of its abundance (usually cover).
dominant species
constant species with high percent cover in a vegetation type or layer; several species may co-dominate; the constancy class is typically ≥ IV.
dry (soil moisture)
see “moisture regime classes”.
dwarf shrub
a perennial woody plant that has a prostrate growth form and occurs within 10 cm of the ground. By CNVC convention, dwarf shrubs are included in the herb layer.
dwarf shrubland
see “physiognomy”.
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edaphic
resulting from, or influenced by, factors inherent in the soil or other substrates rather than climatic factors.
eolian
see “soil parent material”.
ericaceous species
species of the family Ericaceae (e.g., Vaccinium myrtilloides)
eutrophic
nutrient-rich, as in water or substrate.
existing vegetation
plant species and vegetation structure found at a given location at the time of observation (as opposed to potential vegetation).
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feathermoss
a group of moss species with featherlike branches that often form extensive ground cover, especially under closed coniferous canopies. The main feathermoss species are Pleurozium schreberi, Ptilium crista-castrensis, and Hylocomium splendens. In parts of Canada Kindbergia oregano, Brachythecium spp., Abietinella abietina, Rhytidiadelphus loreus and R. triquetrus are sometimes included in the feathermoss group.
fen
a minerotrophic peatland receiving water enriched by dissolved minerals; water levels often fluctuate; fens can be treed or non-treed, but vegetation is typically dominated by shrubs, graminoid species and brown mosses. See “bog”, “marsh”, “swamp”.
fidelity
the degree to which occurrence of a species is confined to a given vegetation type or habitat condition.
fine loamy soil
see “soil rooting zone substrate”.
fine sand
see “soil rooting zone substrate”.
fire cycle
the theoretical time (in years) required to burn an area equivalent to the size of the area of interest. For CNVC factsheet descriptions, the areal units are the Homogeneous Fire Regime (HFR) zone(s), defined by Boulanger et al. (2014), in which the CNVC unit occurs. Within each HFR zone, fire cycle was calculated as: 100 / (percent annual area burned). For portions of some HFR zones, CNVC interpretation of fire cycle was modified by additional information from published regional studies. CNVC Fire cycle classes are:
short: (<100 years)
intermediate: (100-270 years)
long: (270-500 years)
very long: (>500 years)
fluvial
see “soil parent material”.
folic
see “Folisolic soil”.
Folisolic soil
in the Canadian System of Soil Classification, a great group of soils in the Organic order composed of upland organic (folic) materials, generally of forest origin, that are either 40 cm or more in thickness, or are at least 10 cm thick if overlying bedrock or fragmental material.
forb
a non-graminoid herb with relatively broad leaves and/or showy flowers, including monocots and dicots.
forb meadow
see “physiognomy”.
forest
see “physiognomy”.
Formation (CNVC/USNVC)
a combination of dominant and diagnostic growth forms that reflect global macroclimatic conditions as modified by altitude, seasonality of precipitation, substrates, and hydrologic conditions. For example, F001 Boreal Forest and Woodland. The Formation is third (from the top) level in the CNVC / USNVC  hierarchy. For more information on the CNVC hierarchy, see The CNVC Hierarchy.
Formation Class (CNVC/USNVC)
a broad combination of general dominant growth forms that are adapted to basic moisture, temperature, and/or substrate or aquatic conditions. For example, C01 Forest and Woodland. The Formation Class is the first (top) level in the CNVC / USNVC hierarchy. For more information on the CNVC hierarchy, see The CNVC Hierarchy.
Formation Subclass (CNVC/USNVC)
a combination of general dominant and diagnostic growth forms that reflect global mega- or macroclimatic factors driven primarily by latitude and continental position, or that reflect overriding substrate or aquatic conditions. For example, S15 Temperate & Boreal Forest & Woodland. The Formation Subclass is the second (from the top) level in the CNVC / USNVC hierarchy. For more information on the CNVC hierarchy, see The CNVC Hierarchy.
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glacial outwash (soil and landform)
sediments that were carried by glacial meltwater and deposited away from a receding glacier See “soil parent material - glaciofluvial”.
glaciofluvial
see “soil parent material”.
glaciolacustrine
see “soil parent material”.
glaciomarine
see “soil parent material”.
Gleysolic soil
in the Canadian System of Soil Classification, soils in the Gleysolic order that are saturated with water and under chemical reducing conditions either continuously or during some period of the year, as indicated either by gleying (a greenish-blue-grey soil colour) or mottling in the soil profile.
graminoid
a flowering, monocotyledonous herb with relatively long, narrow leaves and inconspicuous flowers with some parts reduced to bracts, primarily including grasses (Poaceae), sedges (Cyperaceae), and rushes (Juncaceae).
grassland
see “physiognomy”.
Group (CNVC)
for upland vegetation that includes zonal vegetation: an aggregation of Alliances within the regional vegetation defined by a Macrogroup, with consistency in dominant and/or diagnostic species. Groups describe regionally generalized  vegetation pattterns attributable to ecological drivers such as edaphic or geological conditions within the Macrogroup (subtype), successional relationships within the Macrogroup (subtype), etc. For example, CG0014 Cordilleran Boreal Mesic Trembling Aspen - White Spruce Forest.
for azonal vegetation: a vegetation unit that is defined by a relatively small set of diagnostic plant species (including dominants and codominants), broadly similar composition, and diagnostic growth forms that reflect regional mesoclimate, geology, substrates, hydrology, and disturbance regimes.
The Group is the sixth (from the top) level in the CNVC hierarchy. For more information on the CNVC hierarchy, see The CNVC Hierarchy.
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habitat
the living place of an organism or biological community, characterized by the combination of its physical and biotic properties together with intrinsic ecological processes.
hardwood
broad-leaved tree species; a term typically used in Canada to contrast with conifer tree species. Most broad-leaved species in Canada are cold-deciduous (e.g., Populus spp.) but some are evergreen (e.g., Arbutus menziesii).
heath species
see “ericaceous species”.
herb
a nonwoody vascular plant; includes pteridophytes, forbs and graminoids.
herbaceous vegetation
vegetation dominated by herbs.
horizon (soil)
a layer of soil or soil material approximately parallel to the land surface that differs from adjacent genetically related layers in properties such as colour, structure, texture, consistence, and chemical, bioiogical, and mineralogical composition.
humus
the fraction of soil organic matter remaining after most of the plant and animal residues have decomposed. It is dark coloured and amorphous.
humus form
partially decomposed organic materials that accumulate at the soil surface on terrestrial and semi-terrestrial sites, classified according to occurrence and relative thickness of soil organic horizons as well as the degree and mechanism of humus incorporation into mineral soil horizons. The CNVC recognizes four classes of humus forms:
moder: a terrestrial humus form characterized by unmatted, partially decomposed plant material; decomposition results primarily from the activity of soil fauna; in moder humus forms, decomposed organic matter is weakly incorporated into the surface mineral soil by soil fauna, but the organic layers are typically distinct from the mineral soil.
mor: a terrestrial humus form characterized by raw plant material, usually matted, with a distinctive boundary that occurs at the mineral soil surface; fungal activity is the primary method of decomposition.
mull: a terrestrial humus form characterized by an intimate mixture of well-humified organic matter and mineral soil; decomposition is primarily the result of soil faunal activity; mixing of organic matter with underlying mineral soil is the result of the activity of burrowing soil fauna (primarily earthworms).
peatymor: a semiterrestrial humus form that develops under conditions of prolonged soil saturation due to elevated water tables; characterized by an accumulation of peat that is less than 40 cm deep.
hydric
pertaining to a habitat that has or requires abundant moisture.
hydromorphic
pertaining to plants having structural or functional adaptations for living in water-dominated or aquatic habitats.
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indicator species
a species with known fidelity to certain habitat conditions, and thus serving as an indicator of, for example, climate, soil moisture, soil nutrients, flooding regime, disturbance history, etc.
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krummholtz
a scrubby, stunted growth form of trees, often forming a characteristic zone at the limit of tree growth in extreme environments.
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layer (vegetation)
a structural component of a plant community defined by dominant growth form(s) of approximately the same height (e.g., tree, shrub, herb, or non-vascular layer).
lacustrine
see “soil parent material”.
lichen
a composite plant consisting of a fungus living in symbiosis with an alga.
lithology
study or description of the macroscopic features of rocks or rock formations, e.g., grain size, mineral composition, colour, etc.
lithic layer
bedrock occurring below a depth of 10 cm of a soil surface, within the vertical section upon which soil classification is based (in most Canadian soils, according to the Canadian System of Soil Classification, the minimum depth to classify a soil in the absence of a lithic layer is usually 1 m for mineral soils and 1.6 m for organic deposits).
lithomorphic
pertaining to plants having structural or functional adaptations for living on rock surfaces or in rocky substrates, i.e., particle sizes larger than 2 mm in diameter.
liverwort
a class of bryophytes (Hepaticae), either leafy (like mosses) or flattened with no differentiated stems and leaves. See “bryophyte”.
Luvisolic soil
in the Canadian System of Soil Classification, an order of soils that have eluvial (Ae) horizons, and illuvial (Bt) horizons in which silicate clay is the main accumulation product. The soils develop in base-saturated parent materials under forest or forest-grassland transition vegetation in subhumid to humid, mild to very cold climates.
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Macrogroup (CNVC)
for upland vegetation that includes zonal vegetation: a regionally distinct subset of plant species composition, abundance and/or dominance, representing primary regional climatic gradients as reflected in vegetation patterns on circum-mesic ("zonal") sites. For example, M496 West-Central North American Boreal Forest.
for azonal vegetation: a vegetation unit that contains moderate sets of diagnostic plant species and diagnostic growth forms that reflect subcontinental to regional biogeographic composition and subcontinental to regional mesoclimate, geology, substrates, hydrology, and disturbance regimes.
The Macrogroup is the fifth (from the top) level in the CNVC / USNVC hierarchy. For more information on the CNVC hierarchy, see The CNVC Hierarchy.
marine
see “soil parent material”.
marsh
a non-treed mineral wetland with periodic or persistent standing water that is generally nutrient-rich; vegetation is dominated by graminoids, shrubs, forbs or emergent aquatic plants. See “fen”, “bog”, “swamp”.
matrix community
a plant community that forms extensive and often contiguous cover. Matrix communities occur on the most extensive landforms and typically have wide ecological tolerances. They are often influenced by large-scale processes such as climate and fire.
meadow
a vegetation community characterized by grass and/or forb species, often occurring on moist sites.
medium (nutrient regime)
see “nutrient regime classes”.
mesic (soil moisture)
see “moisture regime classes”.
meso topoposition
topoposition at the scale of the local landscape (see topoposition). By CNVC convention, the meso topoposition classes are: crest/upper slope, mid-slope, lower/toe slope, depression, and level.
mesomorphic
pertaining to plants requiring environmental conditions of moderate moisture and temperature or which are only partially protected against desiccation.
mesophyte
a plant that grows on mesic soil moisture conditions.
mineral wetland
a wetland ecosystem characterized by minimal or no peat accumulation.
minerotrophic
nourished by mineral water; referring to wetlands that receive nutrients from flowing or percolating groundwater (and surface water), in addition to precipitation.
mixedwood
forest stands composed of both conifer and broad-leaved tree species, each representing (by CNVC convention) > 10% of the total stand canopy cover. In many mapping applications, the cover thresholds for mixedwood designation require between 25% and 75% composition by each of the conifer and broad-leaved components.
moder
see “humus form”.
moist (soil moisture)
see “moisture regime classes”.
moisture regime class
the available moisture supply for plant growth estimated in relative or absolute terms. The CNVC uses an index of relative moisture regime, defined as the potential capacity of a soil to hold, lose or receive water, as determined from the properties of the soil as well as site position on the landscape, regardless of climate. The CNVC recognizes five moisture regime classes.
very dry: water removed extremely rapidly in relation to supply; soil is moist for a negligible time after precipitation; primary water source is precipitation.
dry: water removed rapidly to very rapidly in relation to supply; soil is moist for brief periods following precipitation; primary water source is precipitation.
mesic: water removed readily to somewhat slowly in relation to supply; soil may remain moist for a significant, but sometimes short, period of the year; in moderate to fine-textured soils, the primary water source is precipitation; in coarse-textured soils the primary water source is precipitation and/or limited seepage. In mesic soils, the available soil moisture reflects average climatic inputs.
moist: water removed slowly enough to keep soil wet for a significant part of the growing season; seepage, mottling and gley colours common; primary water source is seepage.
wet: water removed slowly enough to keep the water table at, above or near the soil surface for most of year; deep organic or organic over gleyed mineral soils; primary water source is the permanent water table, often with seepage.
mor (soil humus form)
see “humus form”.
moraine
see “soil parent material”.
mottle (soil)
spots or blotches of different colours or shades of colours interspersed with the dominant soil colour, usually the result of alternating aerobic and anaerobic soil conditions and indicative of poor drainage.
mull
see “humus form”.
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natural vegetation
vegetation that occurs spontaneously without regular management, maintenance or species introductions / removals, and that generally has a strong component of native species; where anthropogenic impacts are apparent, the resulting physiognomic and floristic patterns have a clear, naturally maintained analogue.
non-soil
see “soil rooting zone substrate”.
nutrient regime class
the relative level of nutrient availability for plant growth. The CNVC recognizes four nutrient regime classes.
poor: available nutrients are low to very low.
medium: available nutrients are average.
rich: available nutrients are abundant.
saline: excess salt accumulation.
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ombrogenous
see “ombrotrophic”.
ombrotrophic
an ecological system that derives its nutrients solely (or primarily) from precipitation.
organic
see “Organic soil”, “soil parent material”, “soil rooting zone substrate”.
Organic soil
in the Canadian System of Soil Classification, an order of soils that have developed dominantly from organic deposits. The majority of Organic soils are saturated for most of the year, unless artificially drained, although some of them are not usually saturated for more than a few days. They include most of the soils commonly known as peat, muck, or bog and fen soils. Most organic soils are saturated with water for prolonged periods. These soils occur widely in poorly and very poorly drained depressions and level areas in regions of subhumid to perhumid climate and are derived from vegetation that grows in such sites. However, one group of Organic soils (Folisols) consists of upland (folic) organic materials, generally of forest origin. These Folisols are well to imperfectly drained, although they may become saturated after rainfall or snowmelt.
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paludification
the process of gradual peat accumulation under poor drainage conditions and a slowly rising water table.
patch (landscape)
an area in a landscape differing in appearance from its surroundings. See patch community.
patch community
a plant community that forms an area of interrupted cover differing from its surroundings. Large patch communities are associated with environmental conditions that are more specific than those of matrix communities, and that are less common or less extensive in the landscape. Large patch community types are influenced by large-scale processes, but these tend to be modified by specific site features that influence the community. Small patch community types are characterized by localized, small-scale ecological processes that can be quite different from the large-scale processes operating in the overall landscape.
peatland
a wetland ecosystem characterized by an accumulation of peat ≥ 40 cm deep.
peatymor
see “humus form”.
physiognomy
the structure or outward appearance of vegetation or of a plant community as expressed by the dominant growth forms. The CNVC recognizes seven physiognomy types:
forest: a vegetation community characterized by tree species > 5 m tall (by CNVC convention), the crowns of which generally form a continuous canopy with typically > 30% cover (by CNVC convention); a large area of tree-dominated stands.
woodland: a vegetation community characterized by tree species > 5 m tall (by CNVC convention), the crowns of which form a sparse, discontinuous canopy as a result of ecological limitations such as climate, shallow soils, wetlands, etc; by CNVC convention, woodland canopies are typically between 10% and 30% cover.
shrubland: a vegetation community characterized by shrub species, > 10 cm tall.
grassland: a vegetation community characterized primarily by grass species, typically occurring on arid sites.
forb meadow: a vegetation community characterized by forb species, often occurring on moist sites.
dwarf shrubland: a vegetation community characterized by shrub species that have a prostrate growth form and are <10 cm tall.
cryptogamic vegetation: vegetation characterized by cryptogamic species, typically bryophytes and lichens.
plant community
a combination of plants that are co-dependent on their local habitat, and that influence one another and modify their immediate environment; also, a concrete or real unit of vegetation for survey purposes (see stand).
plot (vegetation classification)
a sampling area of defined size and shape that is intended for characterizing the vegetation and habitat of a stand.
Podzolic soil
in the Canadian System of Soil Classification, an order of soils having B horizons in which the dominant accumulation product is amorphous material composed mainly of humified organic matter combined in varying degrees with Al and Fe. Typically Podzolic soils occur in coarse- to medium-textured, acid parent materials, under forest or heath vegetation in cool to very cold, humid to perhumid climates.
podzolization (soil development)
the process of mobilization and removal (leaching) of dissolved compounds of organic matter, aluminum and iron, as well as clay minerals, from surface (A) horizons and deposition in lower (B) horizons.
poor (nutrient regime)
see “nutrient regime classes”.
potential vegetation
the plant species and vegetation structure (i.e., plant community) that would become established if all successional sequences were completed at a given location without anthropogenic interference under the present climatic and edaphic conditions. Potential vegetation is conceptually similar to ‘climax vegetation’, however, in areas of frequent, on-going natural disturbance (e.g., boreal climatic regions with a short fire-return interval) ‘climax’ is a difficult concept to apply; in these situations, the potential vegetation concept can be applied to the community that theoretically best typifies the projected successional endpoint.
presence (vegetation)
percentage of plots in which a species is found (e.g., a species found in 25 of 100 plots has a presence of 25%);.equivalent to “constancy” and "frequency of occurrence".
pteridophyte
a vascular plant that reproduces by spores, e.g., ferns, horsetails, etc.
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regolith
the unconsolidated mantle of weathered rock and soil material overlying solid rock.
Regosolic soil
in the Canadian System of Soil Classification, an order of soils having no horizon development or development of the A and B horizons insufficient to meet the requirements of the other soil orders.
rich (nutrient regime)
see “nutrient regime classes”.
riparian
refers to terrain, vegetation or simply a landscape position adjacent to or associated with freshwater, generally rivers and streams, but can include the fringe of lakes, ponds and flood plains.
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saline (nutrient regime)
see “nutrient regime classes”.
semi-natural vegetation
vegetation that occurs spontaneously without regular management, maintenance or species introductions / removals, but has been sufficiently altered in terms of species composition or vegetation structure by anthropogenic activity that no clear natural analogue is known.
seral
recognizably different stages along a successional path or sere.
seral dynamics
see “succession”.
shallow soil
see “soil rooting zone substrate”.
shrub
a perennial woody plant, shorter than a tree (i.e., by CNVC convention < 5 m tall), that generally has several erect or prostrate stems which give it a bushy appearance. By CNVC convention, tree species < 5 m tall are classed as shrubs.
shrubland
see “physiognomy”.
silty soil
see “soil rooting zone substrate”.
site
the place or category of places, considered from an environmental perspective, that determines the type and quality of plants that can grow there.
soil
naturally occurring, unconsolidated mineral material or organic material greater than 10 cm thick that occurs at the earth’s surface and is capable of supporting plant growth; soil development involves climatic and biotic factors, as conditioned by relief and hence water regime, acting through time on geological materials and thus modifying the properties of the soil parent material.
soil parent material
the unconsolidated and more or less chemically unweathered material from which soil develops by pedogenic processes. The CNVC recognizes thirteen classes of soil parent materials:
bedrock: the solid rock underlying soil and the regolith or exposed at the ground surface.
colluvium: heterogeneous mixture of soil materials that has reached its present position as a result of direct, gravity-induced movement; usually associated with steep slopes.
eolian: referring to mineral particles moved and sorted by wind; usually fine sands and coarse silt.
moraine / till: a heterogeneous mixture of soil and rock, typically unsorted and unstratified, which has been transported and deposited directly by glacial ice; moraines form a variety of surficial landforms that can occur in both currently glaciated and formerly glaciated regions.
fluvial: pertaining to rivers and streams, or to features produced by the actions of rivers and streams. Fluvial soil deposits are generally coarse textured and stratified.
glaciofluvial: deposits and landforms produced by meltwater streams flowing from wasting glacier ice. Glaciofluvial deposits are generally coarse textured.
lacustrine: referring to freshwater lakes; sediments deposited on a lake bed generally consisting of stratified fine sand, silt and/or clay.
glaciolacustrine: pertaining to or characterized by glacial and lacustrine conditions; deposits made in lakes affected by glacier ice or by meltwaters flowing directly from glaciers. Glaciolacustrine deposits are generally stratified silt, clay and/or fine sand.
marine: unconsolidated deposits of clay, silt, sand, or gravel that are well to moderately well sorted and well to moderately stratified (in some places containing shells) that have settled from suspension in salt or brackish water bodies or have accumulated at their margins through shoreline processes such as wave action and longshore drift.
glaciomarine: relating to process or deposits that involve the action of glaciers and the sea or the action of glaciers in the sea; sediments of a glacial origin laid down from suspension in a marine environment in close proximity to glacier ice. Glaciomarine sediments are generally fine textured.
organic: sediments of mostly organic materials resulting from the accumulation of decayed vegetative matter; usually ≥ 40 cm thick.
anthropogenic: human-made or human-modified materials such that their initial physical properties have been drastically altered.
undifferentiated: a layered sequence of more than three types of genetic material outcropping on a steep erosional escarpment.
soil rooting zone substrate
substrate classes within the zone of maximum rooting. For soil texture class definitions, see Agriculture and Agri-Food Canada, Glossary of Terms in Soil Science. The CNVC recognizes ten classes of soil rooting zone substrates:
non-soil: the aggregate of surficial materials that do not meet the Canadian System of Soil Classification definition of soil, including soil materials displaced by unnatural processes such as dumps of earth fill, unconsolidated mineral or organic material thinner than 10 cm overlying bedrock, exposed bedrock, unconsolidated material covered by more than 60 cm of water throughout the year, and organic material thinner than 40 cm overlying water; soil parent material = bedrock, or coarse colluvium e.g., tallus.
shallow soil: soils that have a root restricting depth of < 20 cm (by CNVC convention).
coarse sandy: soils with a B horizon texture of very coarse sand, coarse sand, medium sand, loamy sand, loamy coarse sand, or loamy medium sand (by CNVC convention).
fine sand: soils with a B horizon texture of fine sand or loamy fine sand (by CNVC convention).
coarse loamy: soil with a B horizon texture of very fine sand, loamy very fine sand, loam, any sandy loam (by CNVC convention).
fine loamy: soils with a B horizon texture of loam, silty clay loam, or any sandy clay loam (by CNVC convention).
silty: soils with a “B” horizon texture of silt or silt loam (by CNVC convention).
clayey: soils with a B horizon texture of clay, heavy clay, silty clay, or sandy clay (by CNVC convention).
organic: organic soils that are ≥ 40 cm depth; or woody substrate (by CNVC convention).
ash: soils that consist of unconsolidated volcanic ash.
Soil texture
see “texture”.
Solonetzic soil
in the Canadian System of Soil Classification, an order of soils having B horizons that are very hard when dry and swell to a sticky mass of very low permeability when wet. They occur on saline parent materials in some areas of the semiarid to subhumid Great Plains of west-central Canada in association with Chernozemic soils and to a lesser extent with Luvisolic and Gleysolic soils. Most Solonetzic soils are associated with a vegetative cover of grasses and forbs.
stand
an uninterrupted unit of vegetation, homogeneous in species composition and vegetation structure, with uniform habitat conditions.
stratum
a distinct layer within a plant community; a component of structure. The four strata recognized in the CNVC are: overstory trees, understory woody shrubs and regenerating trees, understory herbs and dwarf shrubs, and bryophytes and lichens.
structure (vegetation)
the spatial pattern of growth forms in vegetation or a plant community, especially with regard to height, abundance, or cover within individual layers.
subassociation
represents species occurrences or dominance patterns that do not indicate ecological differences strong enough to warrant recognition at the association rank.
submesic
a soil moisture condition between dry and mesic.
succession
the temporal progression within vegetation or a plant community whereby one plant species is replaced by another until a stable species assemblage (plant community) for a particular environment is attained.
swamp
a minerotrophic wetland with vegetation characterized by woody plants (trees and/or tall shrubs); swamps can be either peatlands or mineral wetlands. See “fen”, “marsh”, “bog”.
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telluric
of or proceeding from the earth or soil; telluric water is flowing groundwater.
texture (soil)
the relative proportions by weight of different-sized particles; soil texture classes are illustrated in the texture triangle, available: Agriculture and AgriFood Canada, Glossary of Terms in Soil Science, texture.
till
see “soil parent material”.
topoposition
position of a site along a topographic slope gradient. CNVC topoposition classes include crest/upper slope, mid-slope, lower-toe slope, depression, and level. See “Understanding the Factsheet”.
toposequence
a sequence of related soils and/or plant communities that differ due to the influence of relative topographic positions.
tree
a perennial woody plant, typically with a single stem and a more or less definite crown, that is capable of growing > 5 m tall (by CNVC convention).
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undifferentiated soil
see “soil parent material”.
USNVC
United States National Vegetation Classification.
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vegetation
the collective plant cover over an area; the total of the plant communities of a region; the mosaic of plant communities in the landscape.
vegetation type
an abstract grouping of plant communities (e.g., association, alliance) that have similarity in species composition, and physiognomy or structure.
Vertisolic soil
in the Canadian System of Soil Classification, an order of soils that occur in heavy textured materials (> 60% clay) that shrink and swell due to wetting and drying. As a result, horizons diagnostic of other soil orders have either been prevented from forming or have been severely disrupted. The major areas of Vertisolic soils occur in the cool, subarid to subhumid, grassland portion of the Great Plains of west-central Canada.
very dry (soil moisture)
see “moisture regime classes”.
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wet (soil moisture)
see “moisture regime classes”.
wetland
terrain that is saturated with water for sufficient time to promote wetland or aquatic processes as indicated by poorly drained soils, hydrophytic vegetation and various kinds of biological activity that are adapted to a wet environment.
woodland
see “physiognomy”.
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xeromorphic
pertaining to plants having structural or functional adaptations to prevent water loss by evaporation.
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zonal sites
sites that best reflect the regional climate and are least influenced by the local topography and/or soil properties. They tend to have intermediate soil moisture and nutrient regimes, mid slope positions on gentle to moderate slopes, with moderately deep to deep soils and free drainage; see "azonal sites".
zonal vegetation
potential vegetation characteristic of zonal sites.