Soils of the - Agriculture and Agri-Food Canada

STEELHEAD SOILS
Location and Extent : Steelhead soils occupy scattered areas on the uplands and lower mountain slope s
north of the Fraser River and east from Howe Sound . About 330 ha of pure map units and 1430 ha of soi l
complexes dominated by Steelhead soils are mapped . The complexes are mostly with Buntzen soils and, i n
some areas, with Cannel) or Nicholson soils .
Topography and Elevation : The topography of Steelhead soils varies from moderately sloping and gentl y
undulating to steeply sloping or strongly rolling . Slope gradients range from 5 to 20 percent . The soils usuall y
occur in lower slope positions or in slightly depressional locations . Elevations range between 150 and 700 m
above sea level .
Parent Material and Texture : Steelhead soils have developed from moderately coarse textured (an d
occasionally medium-textured) glacial till . Medium-textured aeolian material, usually less than 20 cm thick, i s
mixed into the surface, particularly in the eastern part of the map area . Surface textures vary from loam to sand y
loam while subsurface and subsoil textures are mostly gravelly sandy loam, occasionally varying to loam o r
gravelly loamy sand . Moderate stone contents are usual and the subsoil is strongly cemented below about 8 0
cm .
Soil Moisture Characteristics : Steelhead soils are imperfectly drained . They are moderately pervious i n
the surface and subsurface ; this decreases to slow in the cemented subsoil . They also have moderate wate r
holding capacity and slow surface runoff . The slightly depressional and lower slope landscape positions allo w
temporary perched watertables to develop above the cemented layer due to seepage from upslope .
General Soil Description : Steelhead soils usually have 10 to 15 cm of organic forest litter on the soi l
surface, the lower two-thirds of which is partially to well-decomposed and dark reddish brown to black in colour .
The organic surface layer is underlain by 2 to 5 cm of friable, gray to grayish-brown, strongly leached, loam y
material which, in turn, is abruptly underlain by about 15 cm of friable to firm, moderately structured, dark
reddish brown to black, loamy soil containing a few, scattered, moderately cemented patches . This zone i s
underlain by about 50 cm of friable, weakly structured, strong brown, yellowish-red or yellowish-brown, sandy o r
loamy material containing a few, distinct, reddish mottles in the upper part and common to many mottles in th e
lower part . Abruptly under this is extremely firm, massive, strongly cemented, sandy material, grayish-brown t o
olive-gray in colour, which contains common, yellowish-red mottles . A zone of root concentration, 5 to 10 c m
thick and dark brown to reddish-brown in colour, usually immediately overlies the cemented zone . The
cemented zone grades to unweathered, olive-gray to grayish-brown glacial till below about 150 cm . Soil
reaction grades from extremely acid in the upper soil to medium acid in the lower subsoil . Soil classification i s
Duric Ferro-Humic Podzol.
Commonly Associated Soils : Buntzen and Cannell soils commonly occur in close association wit h
Steelhead soils . Buntzen soils are generally similar to Steelhead soils except that they usually occup y
somewhat higher landscape positions and are well to moderately well drained . Cannel) soils differ by bein g
underlain by bedrock within 100 cm of the surface and are wll to rapidly drained .
Vegetation : Most areas of Steelhead soils have been logged and currently support a second-growth fores t
that includes coast Douglas-fir, western hemlock and western red cedar with red alder and maple . Rooting i s
unrestricted in the upper 80 to 100 cm but is severely impeded below that by the cemented subsoil . Well defined
root concentrations (root mat) are usually present immediately above the cemented material .
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