Table 4 (cont'd).
Class
Description
Lowland Wet
Flat to gently sloping low-lying areas on lowland loess, abandoned floodplains, and retransported
Broadleaf
deposits with vegetation dominated by broadleaf trees. Soils are loamy with thin surface organic layers,
Forest
poorly drained because of permafrost, and wet, and have neutral pH and slightly elevated electrical
conductivities indicative of groundwater movement. The closed or open canopy is dominated by Betula
papyrifera and understory species include Picea glauca, Rosa acicularis, Salix bebbiana, Calamagrostis
canadensis, and Equisetum sylvaticum.
Lowland Wet
Flat to gently sloping low-lying areas on lowland loess, abandoned floodplains, and retransported
Mixed Forest
deposits with vegetation dominated by mixed forests. Soils are loamy with moderately thick surface
organic horizons, poorly drained because of permafrost, wet, and moderately acidic. The forest canopy is
co-dominated by Betula papyrifera and Picea mariana (occasionally P. glauca). Common understory
species include Alnus crispa, Rosa acicularis, Calamagrostis canadensis, Equisetum sylvaticum, and
Hylocomium splendens.
Lowland Wet
Flat to gently sloping low-lying areas on lowland loess, abandoned floodplains, and
Needleleaf
retransported deposits with vegetation dominated by needleleaf trees. Soils are loamy with moderately
Forest
thick surface organic horizons, poorly drained because of permafrost, wet, and moderately acidic.
Dominant plants include Picea mariana, Ledum groenlandicum, Betula nana, Vaccinium uliginosum, V.
vitis-idaea, Rubus chamaemorus, Hylocomium splendens, Sphagnum spp., and Pleurozium schreberi.
Lowland Wet
Flat to gently sloping low-lying areas on lowland loess, abandoned floodplains, and retransported
Low Scrub
deposits with vegetation dominated by low shrubs. Soils are loamy with moderately thick surface organic
horizons, poorly drained because of permafrost, wet, and moderately acidic. Common plants include
Betula nana, Vaccinium uliginosum, Picea mariana, Salix planifolia, Ledum groenlandicum, Rubus
chamaemorus, Hylocomium splendens, and Sphagnum spp.
Lowland
Flat to gently sloping low-lying areas on lowland loess, abandoned floodplains, and retransported
Tussock
deposits with vegetation dominated by sedge tussocks. Soils are organic (>40 cm) or loamy with thick
Scrub Bog
organic layers, poorly drained because of permafrost, wet, and strongly acidic. Dominant plants include
Eriophorum vaginatum, Picea mariana, B. nana, V. uliginosum, L. decumbens, Empetrum nigrum,
Rubus chamaemorus, and Sphagnum spp.
Lowland Dwarf Flat to gently sloping low-lying areas on lowland loess, abandoned floodplains, and retransported
Scrub Bog
deposits with vegetation dominated by dwarf shrubs. Soils are organic (>40 cm), poorly drained due to
permafrost, wet, and strongly acidic. Vegetation is dominated by Rubus chamaemorus and Sphagnum
spp. and includes P. mariana, L. decumbens, E. nigrum, Oxycoccus microcarpus, and Andromeda
polifolia. Uncommon and not mapped.
Lowland Fen
Low-lying swales on retransported deposits, lowland loess, and abandoned floodplains with
Meadow
vegetation dominated by sedges. Soils are organic, saturated with water near the surface, and weakly
minerotrophic (poor fens) due to groundwater movement. Dominant plants include Eriophorum
angustifolium, Carex aquatilis, Betula nana, Vaccinium uliginosum, and Sphagnum spp. Uncommon
and not mapped.
Lacustrine
Basins in fine-grained lacustrine deposits with vegetation dominated by grasses. Soils are loamy,
Moist Meadow somewhat well drained, moist, and usually mottled at depth. Permafrost is absent. Vegetation is
dominated by Calamagrostis canadensis, and frequently includes Salix bebbiana, S. planifolia, or
Betula nana.
Lacustrine Fen Basins or pond margins with vegetation dominated by sedges. Soils have well-developed fibric
Meadow
sedge peat over fine-grained lacustrine deposits (shore fens), and are saturated to the surface and
slightly acidic. Permafrost is absent. Common plants include Carex aquatilis, C. rostrata, C. canescens,
Eriophorum angustifolium, Equisetum fluviatile, and Hippuris vulgaris. Not mapped because spectrally
indistinct.
Ponds and
Lacustrine waterbodies with or without emergent or floating vegetation. Lakes are associated with thaw
Lakes
basins formed by permafrost degradation and kettle depressions formed by melting of glacial ice in
moraines. Water usually is deep (>1.5 m) and does not freeze to the bottom during the winter. Common
plants include Potamogeton alpinus, P. foliosus, P. gramineus, Nuphar polysepalum, and Isotesmuricata
Riverine
Flat, barren areas on active riverbed gravels adjacent to rivers that are inundated frequently. Soils
Gravelly
range from dry to wet. Surface is nearly free of vegetation (<30% cover), or colonized by pioneer
Barrens
vegetation in less frequently flooded areas. Pioneer species include Potentilla multifida, Agropyron
pauciflorum, Elaeagnus commutata, Dryas drummondii, and Oxytropis campestris.
Riverine
Flat, less-frequently flooded areas on inactive glaciofluvial outwash deposits with vegetation
Gravelly Low
dominated by low and tall shrubs. Soils are stratified to massive gravel with occasional thin and sandy
and Tall Scrub layers, lacking in organics, excessively drained, dry, and slightly acidic. The early successional vegeta-
tion is highly variable, and frequently includes Elaeagnus commutata, Potentilla multifida, Populus
balsamifera saplings, Salix alaxensis, Potentilla fruticosa, Oxytropis campestris, and occasionally Alnus
tenuifolia. Uncommon and not mapped.
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