The Alderwood series consists of moderately deep, moderately well drained soils formedin glacial till. Alderwood soils are on glacially modified foothills and valleys and haveslopes of 0 to 65 percent. The average annual precipitation is about 40 inches, and themean annual temperature is about 50 degrees F.
TYPICAL PEDON: Alderwood gravelly loam - forested. (Colors are for moist soilunless otherwise noted.)
Ap--0 to 7 inches; very dark grayish brown (10YR 3/2) gravelly sandy loam, brown(10YR 5/3) dry; moderate fine granular structure; slightly hard, very friable, slightlysticky and slightly plastic; many fine roots; few fine interstitial pores; slightly acid (pH6.2); abrupt smooth boundary. (3 to 7 inches thick)
Bs1--7 to 21 inches; dark yellowish brown (10YR 4/4) very gravelly sandy loam,yellowish brown (10YR 5/4) dry; weak medium subangular blocky structure; slightlyhard, very friable, nonsticky and nonplastic; many fine roots; many fine tubular andinterstitial pores; 35 percent pebbles; diffuse smooth boundary; slightly acid (pH 6.2).
Bs2--21 to 30 inches; dark brown (10YR 4/3) very gravelly sandy loam, pale brown(10YR 6/3); dry; weak medium subangular blocky structure; slightly hard, very friable,nonsticky and nonplastic; common fine roots; few very fine tubular pores; 40 percentpebbles; slightly acid (pH 6.2); clear wavy boundary. (Bs horizon 15 to 30 inches thick)
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INDIANOLA SERIES
The Indianola series consists of deep, somewhat excessively drained soils formed insandy glacial drift and minor amounts of volcanic ash. Indianola soils are on terraces,terrace escarpments, eskers, and kames at elevations of near sea level to 1,000 feet.Slopes are 0 to 90 percent. The mean annual precipitation ranges from 30 to 55 inchesand the mean annual temperature is about 50 degrees F.
TYPICAL PEDON: Indianola loamy sand-forested. (Colors are for moist soil unlessotherwise stated.)
A--0 to 6 inches;dark reddish-brown (5YR 3/3) loamy sand, brown (10YR 5/3) dry; weakcoarse and medium subangular blocky structure; soft, very friable, nonsticky andnonplastic; many very fine and few coarse and medium roots; common fine tubularpores; neutral (pH 6.8); abrupt smooth boundary. (1 to 9 inches thick)
Bw--6 to 13 inches; dark reddish-brown (5YR 3/4) loamy sand, pale brown (10YR 6/3)dry; weak coarse and medium subangular blocky structure; soft, very friable, nonstickyand nonplastic; common very fine and few medium roots; few fine tubular pores; neutral(pH 6.8); clear smooth boundary. (3 to 10 inches thick)
BC--13 to 25 inches; dark brown (10YR 4/3) loamy sand, pale brown (10YR 6/3) dry;massive; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; fewvery fine tubular pores; 5 percent rounded pebbles; neutral (pH 6.6); clear smoothboundary. (3 to 12 inches thick)
C1--25 to 35 inches; dark yellowish-brown (10YR 4/4) sand, light brownish gray (2.5Y6/2) single grain; loose; few very fine roots; few very fine tubular pores; 5 percentrounded pebbles; neutral (pH 6.8); gradual wavy boundary. (4 to 24 inches thick) 23
KITSAP SERIES
The Kitsap series consists of deep, moderately well drained soils formed in lacustrinesediments. Kitsap soils are on terraces and terrace escarpments and have slopes of 0 to70 percent. The mean annual precipitation is about 37 inches. The mean annualtemperature is about 50 degrees F.
TYPICAL PEDON: Kitsap silt loam - pasture. (Colors are for moist soil unlessotherwise noted.)
Ap--0 to 6 inches; very dark grayish brown (l0YR 3/2) silt loam, grayish brown (l0YR5/2) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly stickyand slightly plastic; many very fine roots; medium acid (pH 5.8); abrupt smoothboundary. (3 to 6 inches thick)
B2l--6 to l0 inches; dark brown (l0YR 4/3) silt loam, pale brown (l0YR 6/3) dry;moderate fine subangular blocky structure; slightly hard, friable, slightly sticky andslightly plastic; many very fine roots; few very fine pores; many 2 to 5 mm light brown(7.5YR 6/4) concretions; medium acid (pH 6.0); clear wavy boundary. (3 to l2 inchesthick)
B22--l0 to l7 inches; brown (l0YR 4/3) silty clay loam, pale brown (l0YR 6/3) dry;moderate medium subangular blocky structure; hard, firm, sticky and plastic; many veryfine roots; common very fine pores about 3 percent fine pebbles; few 2 to 5 mm lightbrown (7.5YR 6/4) concretions; few silt balls; few krotovinas; slightly acid (pH 6.4);clear wavy boundary. (4 to 22 inches thick) 24
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BELLINGHAM SERIES
The Bellingham series consists of deep, poorly drained soils formed in loess, alluvium,and lacustrine sediments. These soils are in depressions. Slopes of 0 to 3 percent. Theaverage annual precipitation is about 48 inches and the mean annual temperature is about50 degrees F.
TYPICAL PEDON: Bellingham silty clay loam - pasture. (Colors are for moist soilunless otherwise noted. All textures are apparent field textures.)
Ap--0 to 5 inches; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; strongfine granular structure; hard, friable, sticky and plastic; many fine roots; moderately acid(pH 5.8): abrupt smooth boundary. (4 to 9 inches thick)
Bg1--5 to 8 inches; gray (5Y 5/1) silty clay, light gray (N 7/) dry; few fine distinctyellowish brown (10YR 5/8) mottles; weak medium prismatic structure; very hard, firm,sticky and plastic; many fine roots; many medium tubular and ves icular pores;moderately acid (pH 6.0); clear smooth boundary. (2 to 13 inches thick)
Bg2--8 to 14 inches; dark gray (5Y 4/1) silty clay, light gray (N 7/) dry; few finedistinct yellowish brown (10YR 5/8) mottles; moderate medium prismatic structure; veryhard, firm, very sticky and very plastic; common fine roots; many medium tubular andinterstitial pores; thin patchy pressure faces on peds and lining pores; slightly acid (pH6.2); clear smooth boundary. (4 to 18 inches thick)
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SEATTLE SERIES
The Seattle series consists of deep, very poo rly drained organic soils formed inherbaceous and woody deposits in depressions in river valleys and glacial till plains.Slopes are 0 to 1 percent. Average annual precipitation is about 40 inches. Mean annua ltemperature is about 50 degrees F.
TAXONOMIC CLASS: Euic, mesic Hemic Medisaprists
TYPICAL PEDON: Seattle muck, pasture. (Colors are for moist soil unless otherwisenoted.)
Oap--0 to 11 inches; black (5YR 2/1) sapric material, black (10YR 2/1) dry; about 10percent fibers, less than 1 percent rubbed; strong fine granular structure; hard, veryfriable, nonsticky, nonplastic; many roots; strongly acid (pH 5.4); clear smooth boundary.(10 to 13 inches thick)
Oe1--11 to 17 inches; dark reddish brown (5YR 2/2) hemic material, black (10YR 2/1)and dark brown (10YR 4/3) dry; about 60 percent fibers, 25 percent rubbed; laminarstructure; very hard, very friable, nonsticky, nonplastic; common roots; strongly acid (pH5.1); clear smooth boundary. (3 to 12 inches thick)
Oa2--17 to 21 inches; black (5YR 2/1) sapric material, black (5YR 2/1) dry; about 5percent fibers, less than 1 percent rubbed; massive; very hard, very friable, slightlysticky, slightly plastic; few roots; very strongly acid (pH 4.8); clear wavy boundary. (0 to6 inches thick) 26
Johannessen and MacLennan 200727
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Woodway in Seattle - 1997
Humans can affect oursoils & environment
But so can the animals
SOILS = f (cl, r, o, p, t, …..H)
ESRM 311/SEFS 507 Field Trip Week #3, for use with accompanying map and soil descriptions
Urban fill. Mapped as Andept. This area is a combination of fill from the Lake Washington ship canal and other landfilling. Notice mottled appearance but lack of high water table in the winter. notice lack of OM
Stop 3.
Marsh Island, old trail. Mapped as Seattle series.
Stop 4.
Marsh Island, tall trees. Mapped as Seattle series. Note how most trees are small and spread out this site is an exception. Why?
Stop 5.
Marsh Island view from floating docks. Island mapped as Seattle series. Glacial action has created the many freshwater bodies in the State of Washington. Sedimentation has filled many in. Marsh Island is apparently the result of organic deposition in an environment where decomposition is slow. In addition, filling nearby areas might have pushed up organic material, forming islands. Note water table. Note appearance of OM.
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Mapped as Inceptisol. This
Stop 6.
Foster Island. Mapped as Bellingham (upper) and Seattle (lower areas) series. Clay soil; large trees. Note mottling within the soil profile. What caused this? Would this be a good garden soil? Between Stops 6 & 7. Recent construction on bank to prevent duck erosion. Large boulder on other side of the trail (glacial erratic). Stop at Arboretum building (only if necessary).
Stop 7. French Drain
Azalea Way. Mapped as series. The Arboretum wishes to keep Azalea Way grassed, but not muddy. Unfortunately, the soil situation here encourages subsoil water flow along restrictive layers on the slopes and surfacing on Azalea Way and below.
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water flow
original slope
fillcut
Azalea Way
silty sediments
till
sandy drift
compacted layer
A French drain (a drain that is buried) has been cut along the uphill side of Azalea Way to help alleviate this. Water theoretically passes into the drain and under Azalea Way. Is this working?
water flow
original slope
fillcut
Azalea Way
silty sediments
till
sandy drift
compacted layer
gravel filled french drain
drainage under Azalea Way
Stop 8. Modified French drain. Located at the bottom of the slope as a trench with rock exposed to help drain away (especially) surface water. Mapped as Bellingham series. Note that marks on a map
that look like this...( ) could represent what? Some maps may have different symbols to represent the same parameter. What would this mean to the desired uses of the Arboretum? What steps would need to be taken to increase the suitability of this soil for use by the Arboretum. 31
