Soils of the - Agriculture and Agri-Food Canada

HOOVER SOILS (HV)
Location and Extent : Hoover soils occur on the lower mountain slopes, mainly north of Mission . About 75 h a
of pure map units and 1220 ha of several soil complexes dominated by Hoover soils are mapped . Th e
complexes are mainly with Cannell, Kenworthy and Buntzen soils and Rock Outcrop land type .
Topography and Elevation : The topography of Hoover soils is mostly steeply to very steeply sloping o r
strongly rolling to hilly with slope gradients between 15 and 60 percent . Some extremely sloping areas also
occur with slopes in access of 60 percent . Hoover soils generally lie between 200 and 600 m above sea level .
Parent Material and Texture : Hoover soils have developed from moderately coarse to coarse-textured ,
stony colluvial deposits, usually 1 m or more thick . These usually overlie bedrock, or sometimes, glacial till . At
the lower elevations, small amounts of silty, eolian material is mixed into the surface . Surface, subsurface an d
subsoil textures are usually sandy loam or gravelly sandy loam . Lenses of gravelly loamy sand or loa m
sometimes also occur .
Soil Moisture Characteristics : Hoover soils are moderately well to well drained . They are rapidly perviou s
in the colluvial material but this changes to slow in the underlying glacial till . They have moderate to lo w
waterholding capacity and generally slow surface runoff . Lateral, telluric seepage above the glacial till o r
bedrock during and after periods of heavy rain or snowmelt is usual .
General Soil Description : Hoover soils usually have 5 to 10 cm of raw to well-decomposed coniferou s
forest litter and moss on the mineral soil surface . This is underlain by about 4 to 8 cm of grayish, leached, ver y
friable, sandy material, which, in turn, is abruptly underlain by about 30 cm of dark brown or dark reddish brown ,
friable, sandy material containing substantial amounts of angular gravel and stones . Below this is about 10 to 2 0
cm of similarly textured material which is friable, yellowish-brown in colour and commonly contains a fe w
reddish or brownish mottles in the lower part . The soil then grades to about 40 cm of dark gray or olive-gray ,
friable, unweathered colluvium containing a thin, well defined root mat immediately above the underlyin g
glacial till or bedrock . The underlying till (if present) is hard, dense, olive-gray in colour and usually less than 5 0
cm thick over bedrock . The upper soil reaction is extremely or very strongly acid and grades to strongly o r
medium acid in the lower subsoil . Soil classification is Orthic Humo-Ferric Podzol.
Commonly Associated Soils : Cannell, Eunice and Buntzen soils and Rock Outcrop land type usuall y
occur in close association with Hoover soils . Cannell soils differ from Hoover soils by consisting of between 1 0
and 100 cm of soil over bedrock while Eunice soils differ by having 10 cm or more of organic material ove r
bedrock . Buntzen soils have developed from glacial till and have strongly cemented layers in the subsurfac e
and subsoil .
Vegetation : The vegetation of Hoover soils consists mostly of second-growth forest, dominantly coas t
Douglas-fir, western hemlock and western red cedar . Rooting is generally unrestricted in the colluvial materia l
but is severely restricted below about 1 m depth by the underlying compact glacial till or bedrock .
General Land Use Comments : (1) Hoover soils are unsuited for agriculture due to very steep slopes an d
stoniness . (2) Hoover soils are also unsuited for urban development due to steep to very steep slopes an d
shallowness to bedrock . (3) A limited number of plot measurements indicate Hoover soils are moderately suite d
for forest growth . Measured growth of coast Douglas-fir ranges from about 6 .5 to 8 m3/ha/yr.
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