Introduction and Key to Plant Communities
LOCATION
REDOUBT
AK
Tentative
Series
DVP
5/98
DRAFT
DRAFT
REDOUBT
SERIES
The
Redoubt series consists of very deep, well drained soils formed in a mantle of
ash-influenced loess overlying loamy glacial and glaciolacustrine materials.
Redoubt soils are on nunataks and terraces at low elevations.
Slopes range from 0 to 45 percent. The
mean annual precipitation is about 30 inches, and the mean annual temperature is
about 35 degrees F.
TAXONOMIC
CLASS: Medial over loamy, amorphic Andic Humicryods
TYPICAL
PEDON: Redoubt silt loam - on a northwest facing slope of 6 percent at 400 meter
elevation under Lutz spruce, tall grass, and shrubs.
(All colors are for moist soil)
Oe—0 to 5 cm; mat of roots and partially decomposed organic matter;
clear smooth boundary. (2 to 10 cm thick)
E--5 to 7 cm; dark grayish brown (10YR
4/2) silt loam; weak fine granular structure; very friable, nonsticky and
nonplastic; many very fine and fine roots; 10 percent gravel; extremely acid;
clear wavy boundary. (3 to 8 cm
thick)
Bhs—7 to 9 cm; dusk reddish brown
(5YR 2.5/2) silt loam; moderate fine granular structure; very friable,
smeary; many roots; 10 percent gravel; extremely acid; clear wavy boundary.
(2 to 15 cm thick)
Eb—9 to 12 cm; dark grayish brown (10YR 4/2) silt loam; weak very thin
platy structure; very friable, nonsticky and nonplastic; many roots; 10 percent
gravel; extremely acid; clear wavy boundary.
(3 to 8 cm thick)
Bhsb – 12 to 56 cm; dark reddish brown (5YR 3/3) and (5YR 2.5/2) silt
loam; moderate fine granular structure; very friable, smeary; nonsticky and
slightly plastic; many very fine and fine roots; 10 percent gravel; extremely
acid; clear wavy boundary. (10 to
45 cm thick)
2C—56 to 152 cm; dark grayish brown (2.5Y 4/2) gravelly sandy loam;
massive; friable; 25 percent gravel; strongly acid.
RANGE
IN CHARACTERISTICS: Depth to the 2C horizon ranges from 50 to 80 cm.
The silty solum ranges in thickness from 50 to 80 cm and is bisequal. The
spodic horizon has more than 6 percent organic carbon in at least 10 cm.
Reaction throughout the profile is strongly acid to extremely acid .
The
E and Eb horizons have hue of 2.5Y to 10YR, value moist from 4 or 5, and chroma
moist of 2 or 3. Texture is silt
loam or very fine sandy loam.
The
Bhs and Bhsb horizons have hue of 2.5YR or 5YR, value moist of 2 or 3, and
chroma moist of 2 or 3. Texture is
silt, silt loam or very fine sandy loam.
The
Bs horizons, when present, have moist hue from 5YR or 7.5YR, and value moist of
3 or 4, and chroma moist of 3 through 6. Texture is silt loam or very fine sandy
loam.
The
Bw horizon, when present, has moist hue from 7.5YR to 10YR, and value moist of 3
or 4, and chroma moist of 3 through 4. Texture is silt loam or very fine sandy
loam.
The
BC horizon, when present, has moist hue from 2.5Y to 10YR, and value moist of 3
or 4, and chroma moist of 3 through 4. Texture is silt loam or very fine sandy
loam.
The
2C horizon has moist hue of 2.5Y or 5Y, value moist of 4 or 5, and chroma moist
of 2 or 3. Coarse fragment content
ranges from 0 to 25 percent gravel and 0 to 5 percent cobble.
Texture is sandy loam or silt loam. Coarse fragment content increases
with depth. Consistence is friable
or firm.
COMPETING
SERIES: These are the Puntilla and Chuit series in the same family and the
Iliamna and Redoubt series. Chuit
soils have horizons within the control section that are broken and mixed by
frost action. Puntilla soils have
shorter growing seasons and support stands of subalpine and alpine grasslands.
Iliamna and Talkeetna soils have more than 35 percent coarse fragments in
the lower part of the control section.
GEOGRAPHIC
SETTING: The Redoubt soils occur on nunataks and on terraces at low elevations.
Slopes range from 0 to 45 percent. The
soils formed in loess, mixed with volcanic ash, over loamy glacial and
glaciolacustrine materials. Mean
annual temperature ranges from 33 to 36 degrees F.
Mean annual precipitation ranges from 20 to 35 inches.
GEOGRAPHICALLY
ASSOCIATED SOILS: These are the Iliamna and Talkeetna soils. They also occur on
nunataks but are composed of different parent materials.
DRAINAGE
AND PERMEABILITY: Well drained, negligible to medium runoff, moderately rapid
permeability.
USE
AND VEGETATION: Forestry, wildlife habitat, and recreation. Open to sparse
canopy forest of Lutz spruce and paper birch with understory of alder, tall
grass, and other shrubs.
DISTRIBUTION
AND EXTENT: Southcentral Alaska. The
series is of minor extent.
MLRA
OFFICE RESPONSIBLE: Anchorage, Alaska.
SERIES
PROPOSED: Western Kenai Peninsula, Alaska, 1998.
REMARKS:
Diagnostic features and horizons recognized in this profile include:
spodic horizons from 7 to 56 cm, more than 6 percent organic carbon in 10 cm of
the spodic; amorphous material dominant from 7 to 56 cm; loamy material from 56
to 100 cm.
National
Cooperative Soil Survey
U.S.A.
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Introduction and Key to Plant Communities |
| Contact: Mike Gracz Kenai Watershed Forum PO Box 15301 Fritz Creek, AK 99603 907-235-2218 |
04 May 2007 10:35 |
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