Soils of the - Agriculture and Agri-Food Canada

RODGERS SOILS (RG )
Location and Extent : Rodgers soils occupy small, scattered, high elevation areas in the mountainous ,
northern part of the map area . About 390 ha of pure map units and 470 ha of soil complexes dominated by
Rodgers soils are classified .
Topography and Elevation : The topography varies from moderately to steeply sloping with slope gradients
between 5 and 30 percent . Elevations are in excess of 700 m above sea level .
Parent Material and Texture : Rodgers soils have developed from coarse to moderately coarse textured ,
stony and bouldery alluvial fan deposits . Surface textures vary from stony gravelly loamy sand to stony gravell y
sandy loam while subsurface and subsoil textures range from sandy gravel to gravelly loamy sand, both ver y
stony and bouldery.
Soil Moisture Characteristics : Rodgers soils are well to moderately well drained . They are rapidl y
pervious and have low water holding capacity and slow surface runoff . Substantial amounts of telluric seepag e
flows through the lower subsoil during and after heavy rain or during snowmelt .
General Soil Description : Rodgers soils generally have 15 cm or more of organic forest litter on the soi l
surface, the lower half of which is black to dark reddish brown and well to moderately decomposed . The organi c
litter is underlain by 5 to 10 cm of gray to brownish-gray, friable, strongly leached, sandy material which, in turn ,
is underlain by about 40 cm of dark reddish brown to dark brown soil material that is friable, sandy to gravell y
and contains 50 to 80 percent stones, cobbles and boulders . This zone then grades to about 50 cm of reddish -
brown to yellowish-brown, sandy and gravelly material which varies from friable to firm due to discontinuou s
cementation and contains at least 70 percent stones, cobbles and boulders . Below this is grayish-brown o r
brownish-gray, loose, gravelly parent material containing many stones and boulders . Few to common, reddis h
mottles are also present . Soil reaction ranges from extremely acid in the surface and subsurface to very strongl y
acid in the lower subsoil . Soil classification is Orthic Ferro-Humic Podzol.
Commonly Associated Soils : Sayres, Palisade, Golden Ears and Whonnock soils and Talus land type
often occur in close association with Rodgers soils . Sayres and Palisade soils differ from Rodgers soils by bein g
developed in very steeply sloping colluvial deposits ; additionally, Sayres soils are underlain by bedrock withi n
100 cm of the surface . Golden Ears and Whonnock soils differ by having developed from glacial till and ar e
strongly cemented in the subsoil ; Whonnock soils also differ by being imperfectly rather than well to moderatel y
well drained . The Talus land type differs from Rodgers soils by consisting of actively accumulating rock_ debris .
Vegetation : The forest cover on Rodgers soils is mainly Pacific silver fir, mountain hemlock and some yellow
cedar ; at the lower elevations western hemlock and western red cedar are also present . Rooting depth i s
essentially unrestricted although some impediments to root distribution are present due to the stony an d
bouldery soil characteristics .
General Land Use Comments : (1) Rodgers soils are unsuited for agricultural use due to excessiv e
stoniness and adverse climatic conditions, mainly heavy snow packs which persist into the early part of th e
growing season . (2) Similarily, Rodgers soils are also unsuited for year-round urban or similar uses . Excessive
snowfall during the winter makes access difficult . Soil bearing strengths are adequate but basements and othe r
excavations are difficult to construct due to the stony and bouldery character of the soils. In some areas
Rodgers soils may serve as sources of aggregate . (3) Forest growth is good at the lower elevational range bu t
decreases due to adverse climatic conditions (deep snowpack, short growing season) as elevations increase .
Potential annual wood production by western hemlock and Pacific silver fir is estimated at almost 9 to 12 m3/h a
at the lower elevations .
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