Table 8. Description of ecotypes found on Ft. Wainwright, central Alaska, 1998.
Class
Description
Alpine
Alpine areas above treeline with dry, rocky soils and dwarf scrub vegetation. The soils are well-drained, have thin
Rocky Dry
organic horizons, and frequently have rocks at the surface, are strongly acidic, and are associated with weathered bed
Dwarf Scrub
rock. Permafrost status is uncertain. Vegetation is dominated by dwarf shrubs (mostly Dryas octopetala, with some Salix
arctica, Arctostaphylos alpina). Associated species include sedges (Carex bigelowii), numerous forbs, and lichens (Cladina
spp.).
Alpine Rocky
Alpine areas near treeline with moist, rocky soils and vegetation dominated by low and tall shrubs. Soils have thin to
Moist Tall and
moderately thick organic horizons, are excessively to well-drained, are strongly acidic, and are associated with weath-
Low Scrub
ered bedrock. Permafrost status is uncertain. Vegetation is dominated by shrubs (Betula nana, Salix planifolia, Ledum
decumbens, Vaccinium uliginosum, V. vitis-idaea), sedges (Carex bigelowii), and mosses (Hylocomium splendens, Aulacomnium
turgidum). Scattered Picea glauca (white spruce), P. mariana (black spruce), and Betula papyrifera (paper birch) often are
present.
Upland Wet
Upland areas on north-facing (and some east and west) slopes with variably wet and moist, rocky and loamy soils, and
Needleleaf Forest
vegetation dominated by needleleaf trees. Soils vary from well- to poorly drained, have moderately thick to thick organic
horizons, are strongly acidic, and are associated with residual soils, upland retransported deposits, and upland loess.
Permafrost usually is present on steeper, north-facing slopes. Vegetation is dominated by Picea mariana, ericaceous shrubs
(Ledum groenlandicum, Vaccinium uliginosum, V. vitis-idaea, Empetrum nigrum), and mosses (Hylocomium splendens, Sphag-
num spp.).
Upland Moist
Upland, south-facing areas with moist, rocky to loamy soils and vegetation dominated by needleleaf trees. Soils are
Needleleaf Forest
well-drained, have thin organic horizons, are strongly acidic, lack permafrost, and are associated with residual soils,
upland retransported deposits, and upland loess. The late-successional vegetation is dominated by both Picea glauca
(white spruce) and P. mariana (black spruce), Alnus crispa (green alder), ericaceous shrubs, and feather mosses
(Hylocomium splendens, Pleurozium schreberi).
Upland Moist
Upland, non-south-facing areas with moist, rocky to loamy soils and vegetation dominated by needleleaf and broadleaf
Mixed Forest
trees. Soils are well-drained, have thin organic horizons, are moderately acidic, and lack permafrost. The mid-successional
vegetation is dominated by a closed canopy of Picea glauca, P. mariana, and Betula papyrifera. The understory has Alnus
crispa, Vaccinium vitis-idaea (lingonberry), Cornus canadensis (bunchberry), Calamagrostis canadensis (bluejoint reedgrass),
and feather mosses.
Upland Moist
Upland, south-facing areas with moist, rocky to loamy soils and vegetation dominated by needleleaf and broadleaf
Mixed Forest
trees. Soils are well-drained, have thin organic horizons, are moderately acidic, lack permafrost, and are associated with
(south-facing)
residual soils, upland retransported deposits, and upland loess. The mid-successional vegetation is dominated by a
closed canopy of Picea glauca, P. mariana, Betula papyrifera, and Populus tremuloides (quaking aspen), with Shepherdia
canadensis (soapberry), Viburnum edule (high bushcranberry), Linnaea borealis (twin-flower), and feather mosses in the
understory.
Upland Moist
Upland areas on north-, east-, and west-facing slopes with moist, rocky to loamy soils and vegetation dominated by
Broadleaf Forest
broadleaf trees. Soils are well-drained, have thin organic horizons, are strongly acidic, lack permafrost, are associated
with residual soils, upland retransported deposits, and upland loess. This mid-successional forest has an open to closed
canopy of Betula papyrifera and an understory of Alnus crispa, Rosa acicularis (prickly rose), Cornus canadensis,
Calamagrostis canadensis, and feather mosses.
Upland Moist
Upland areas on warm south-facing slopes with moist, rocky to loamy soils and vegetation dominated by broadleaf
Broadleaf Forest
trees. Soils are well-drained, have thin organic horizons, are strongly acidic, and lack permafrost. This mid-successional
(south-facing)
stage after fire has an open to closed overstory of Populus tremuloides and Betula papyrifera. The understory includes
Picea glauca, Rosa acicularis, Shepherdia canadensis, Cornus canadensis, Linnaea borealis, Calamagrostis canadensis, and
feather mosses.
Upland Moist
Upland areas with moist, rocky to loamy soils and vegetation dominated by tall shrubs. Soils are well-drained, have
Tall Scrub
very thin organic horizons, are strongly acidic, lack permafrost, and are associated with residual soils, upland
retransported deposits, and upland loess. This early successional stage after disturbance is dominated by dense thickets
of Alnus crispa or Salix spp. and abundant leaf litter. Other common plants include Calamagrostis canadensis, Epilobium
angustifolium (fireweed), and the moss Polytrichum juniperinum.
Upland Moist
Upland areas with moist, rocky to loamy soils and vegetation dominated by low shrubs and herbaceous plants. Soils
Low Scrub
are well-drained, have thin organic horizons, and lack permafrost. This early successional stage after fire is dominated
by shrubs (Salix spp., Vaccinium uliginosum, Ledum groenlandicum), Calamagrostis canadensis, Epilobium angustifolium, and
mosses (Polytrichum juniperinum, Ceratodon purpureus).
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