Geoscience Reference
In-Depth Information
Table 18.5 Site conditions favoring ortstein development from the literature and from this review
(Bockheim
2011
)
Soil-forming
factor
Favored
here
a
Description of condition
References
Climate
Ortstein in the Black Forest only occurs
below 900 m
Kaczorek et al. (
2004
)
X
A seasonal desiccation period
enables dehydration and
hardening of a subsoil layer
McKeague and Wang (
1980
)
¼
Organisms
Minimal bioturbation to break up pan
Lapen and Wang (
1999
) X
Adjacent to and upslope from areas with
peat cover
Wang et al. (
1978
)
X
Relief
Free drainage
Karavayeva (
1968
);
Moore (
1976
) and
Kaczorek et al. (
2004
)
X
Restricted drainage
Wang et al. (
1978
) and
Lapen and Wang (
1999
)
X
Fluctuating water table
Dubois et al. (
1990
)
X
Gentle slopes
Lapen and Wang (
1999
) X
Parent
material
Medium and coarse sandy material
Moore (
1976
)
X
Materials enriched in ferromagnesian
minerals
Moore (
1976
)
X
High amount of coarse fragments to act
as “nuclei” for precipitation of Fe,
Al, Si, OC
Lapen and Wang (
1999
)
Availability of fines to bridge sand
grains and slow water movement
McKeague and Wang (
1980
)
and Kaczorek
et al. (
2004
)
Time
Soils older than ca. 4,000 yr
Moore (
1976
)
X
a
Favored: X
¼
favor under most conditions;
¼
favor under some conditions;
¼
do not favor
Table 18.6 Statistical comparison of site factors for soils with
>
50 % ortstein,
<
50 % ortstein,
and geographically associated Spodosols without ortstein. Data for seven soils with placic
horizons are included (Bockheim
2011
)
Property
Ortstein
Some ortstein No ortstein
p value
Placic
Drainage (coded)
a
3.3b
3.8a
3.6ab
0.024
2.4
Mean annual precipitation (mm)
1,218a
944b
1,279a
0.008
3,177
Mean annual air temperature (
C)
10.7a
9.8a
9.9a
0.782
12.8
Slope (%)
10b
12b
20a
0.001
15
Elevation (m)
162b
183b
290a
0.015
495
a
Drainage code: 7
¼
excessively drained; 6
¼
somewhat excessively drained; 5
¼
well drained;
4
¼
moderately well drained; 3
¼
somewhat poorly drained; 2
¼
poorly drained; 1
¼
very poorly
drained
demanding species. In coastal OR soils containing ortstein support sparse stands of
shore pine (
Pinus contorta
var.
contorta
) within an area with western conifers. Both
regions contain an abundance of blueberry (
Vaccinium
spp.), leaf extracts of which
have been employed to experimentally re-cement crushed ortstein (Bronick
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