SUPPLEMENTARY INFORMATION
Soil development and nutrient availability along a two million year
coastal dune chronosequence under species-rich Mediterranean
shrubland in southwestern Australia
Benjamin L. Turner and Etienne Laliberté
This file contains descriptions of soil profiles along the Jurien Bay chronosequence, Western
Australia. There is a description of a profile pit on each of six chronosequence stages ranging in
age from < 100 years to > two million years. The soils were classified according to US Soil
Taxonomy.
Profile: Quindalup Young Dune
Classification:
Profile location:
UTM:
Date and season:
Elevation:
Slope and site position:
Soil moisture regime:
Soil temperature regime:
Parent material:
Vegetation:
Drainage:
Surface features:
Faunal activity:
Coarse fragments:
Rooting depth:
Notes:
Diagnostic features:
ENTISOL: Carbonatic, thermic, Typic Xeropsamments
Close to plot QY18
50J 0308318 6654770
17 August 2012; late wet season
19 m above sea level
Side of a large dune; ~20% slope facing south
Xeric
Thermic
Quindalup sand; young phase
Sparse low stature shrubby vegetation
Extremely well drained
Mostly bare sand
None observed
None
Throughout the profile, but few > 88 cm
Color values are for moist soil and textures are field textures
(i) Ochric epipedon
(ii) Xeric moisture regime
(iii) > 40% carbonate in the mineralogy control section
Horizon description
AC—0 to 12 cm; light brownish grey (2.5Y 6/3; 10YR 7/2 dry) calcareous sand; loose, single grain; many
extremely fine sand binding roots; common medium and few fine roots; few clean quartz grains among
calcareous fragments; smooth gradual boundary.
C1—12 to 88 cm; light grey (2.5Y 7/2; 10YR 8/1 dry) calcareous sand; loose, single grain; moist; few fine patches
of organic matter (decaying roots); few coarse, medium, fine, and very fine roots; smooth gradual boundary.
C2—88+ cm; white (2.5Y 8/1; 10YR 8.5/1 dry) calcareous sand; loose, single grain; dry; very few fine and medium
roots; non-cohesive (collapsing after excavation).
Profile: Quindalup Medium Dune
Classification:
Profile location:
UTM:
Date and season:
Elevation:
Slope and site position:
Soil moisture regime:
Soil temperature regime:
Parent material:
Vegetation:
Drainage:
Surface features:
Faunal activity:
Coarse fragments:
Rooting depth:
Notes:
Diagnostic horizons and features:
ENTISOL: Carbonatic, thermic, Typic Xeropsamments
Road cut near plot QM 26, along the dune to the south
50J 0308536 6655422
18 August 2012; late wet season
11 m above sea level
Backslope of dune; ~10% facing southeast
Xeric
Thermic
Quindalup sand; medium phase
Low stature shrubby vegetation < 1 m high; relatively dense at ground level
Extremely well drained
Some grass and moss on surface
None observed
None
Throughout the profile to 116 cm
Color values are for moist soil and textures are field textures
(i) Ochric epipedon
(ii) Xeric moisture regime
(iii) >40% carbonate in the mineralogy control section
Horizon description
A—0 to 13 cm; very dark grayish brown (2.5Y 3/2; 10YR 5/1 dry) loamy sand; loose, single grain; moist, but dry at
surface; many very fine, and common coarse, medium, and fine roots; smooth clear boundary.
CA—13 to 51 cm; grayish brown (2.5Y 5/2; 10YR 6/1 or 6/1 dry) calcareous sand; loose, single grain; moist; few
coarse, and common medium, fine, and very fine roots; smooth gradual boundary.
C1—51 to 116 cm; pale brown (2.5Y 7/2; 10YR 7/2 dry) calcareous sand; loose, single grain; few fine and medium
roots; smooth gradual boundary.
C2—116+ cm; pale brown (2.5Y 8/2; no change dry) calcareous sand; loose, single grain; moist; no roots; noncohesive, collapsing from exposed faces.
Profile: Quindalup Old Dune
Classification:
Profile location:
UTM:
Date and season:
Elevation:
Slope and site position:
Soil moisture regime:
Soil temperature regime:
Parent material:
Vegetation:
Drainage:
Surface features:
Faunal activity:
Coarse fragments:
Rooting depth:
Notes:
ENTISOL: Siliceous, thermic, Typic Xeropsamments
Road cut near plot QO11
50J 0313077 6658353
13 August 2012; late wet season
20 m above sea level
Crest of a dune
Xeric
Thermic
Quindalup sand; old phase
Shrubby vegetation < 1 m high
Well drained
Bare soils and dry leaves (<10% cover)
None observed
None
Throughout the profile
Color values are for moist soil and textures are field textures. The B horizon is
not cambic because although there is evidence of decalcification and a higher
color value than the underlying C horizon, the texture is not very fine sand or
finer.
Diagnostic horizons and features: (i) Ochric epipedon
(ii) Xeric moisture regime
Horizon description
A—0 to 12 cm; dark greyish brown (10YR 4/2; 2.5Y 5/2 dry) loamy sand; very weak blocky structure; very friable;
common coarse, medium, fine, and very fine roots; smooth clear boundary.
BA—12 to 26 cm; yellowish brown (10YR 5/4; 10YR 6/2 dry) sand; very weak blocky structure; very friable;
common coarse, medium, fine, and very fine roots; smooth gradual boundary.
B1—26 to 60 cm; light yellowish brown (10YR 6/4; 10YR 7/3 dry) sand; loose, single grain; few very fine, fine,
and medium roots; smooth diffuse boundary.
B2—60 to 93 cm; pale brown (2.5Y 7/4; 10YR 8/3 dry) sand; loose, single grain; few very fine, fine, and medium
roots; smooth diffuse boundary.
B3—93 to 165+ cm; pale brown (2.5Y 7/4; 10YR 8/2 dry) sand; (slightly lighter than above); loose, single grain;
few very fine, fine, and medium roots.
Profile: Spearwood Young Dune
Classification:
Profile location:
UTM:
Date and season:
Elevation:
Slope and site position:
Soil moisture regime:
Soil temperature regime:
Parent material:
Vegetation:
Drainage:
Surface features:
Faunal activity:
Coarse fragments:
Rooting depth:
Notes:
INCEPTISOL: Sandy, siliceous, thermic, Calcic Haploxerepts
Jurien Bay East Road; north of road
50J 0314984 6648707
18 August 2012; late wet season
31 m above sea level
Crest of a shallow dune
Xeric
Thermic
Spearwood sand; Tamala Limestone pinnacles within 1 m of the soil surface
Shrubby vegetation < 1 m high
Well drained
Bare soil (~25%) and dry leaves
None observed
None
Throughout the profile
Color values are for moist soil and textures are field textures. The profile
qualifies as an Inceptisol because of the petrocalcic horizon, and as
Haploxerepts because although the petrocalcic horizon is within 150 cm of the
surface, the soil does not have free carbonates in all layers above this. It is a
Calcic Haploxerepts because of the sandy particle-size class and secondary
carbonates within 150 cm of the mineral soil surface.
Diagnostic horizons and features: (i) Ochric epipedon
(ii) Xeric moisture regime
(ii) > 90% resistant material in the sand fraction in the particle control section
(iv) Petrocalcic horizon with upper boundary between 40 and 100 cm below the
soil surface
Horizon description
A—0 to 11 cm; dark grayish brown (10YR 4/2; no change dry) loamy sand; weak coarse blocky structure; very
friable; many very fine, and common medium and fine roots; smooth clear boundary.
AE—11 to 18 cm; brown (10YR 5/3; no change dry) sand; very weak medium blocky structure; very friable;
common medium, fine, and very fine roots; smooth clear boundary.
B1—18 to 33 cm; brownish yellow (10YR 6/6; 10YR 5/6 dry) sand; loose, single grain; common very fine, and few
fine and medium roots; smooth gradual boundary.
B2—33 to 100+ cm; brownish yellow (10YR 6/7; 10YR 6/6 dry) sand; loose, single grain; few very fine, fine, and
medium roots; limestone pinnacles reaching to 40 cm, but sand extending to > 1 m on profile face.
Bkkm—petrocalcic horizon (calcrete) of undetermined thickness, over limestone.
Profile: Spearwood Old Dune
Classification:
Profile location:
UTM:
Date and season:
Elevation:
Slope and site position:
Soil moisture regime:
Soil temperature regime:
Parent material:
Vegetation:
Drainage:
Surface features:
Faunal activity:
Coarse fragments:
Rooting depth:
Notes:
Diagnostic horizons and features:
ENTISOL: Thermic, Xeric Quartzipsamments
Jurien Bay East Road, south of the road
50J 0321438 6651482
17 August 2012; late wet season
60 m above sea level
Crest of a shallow dune; ~5-10% slope
Xeric
Thermic
Spearwood sand
Shrubby vegetation < 1 m high, with a few tall Banksia
Well drained
Bare soil (~50%) and dry leaves
None observed
None
Throughout the profile
Color values are for moist soil and textures are field textures
(i) Ochric epipedon
(ii) Xeric moisture regime
(iii) > 90% resistant material in the sand fraction in the particle control section
Horizon description
A—0 to 11 cm; dark grayish brown (10YR 4/2; 10YR 5/2 dry) loamy sand; weak coarse blocky structure; very
friable; thin crust of organic matter and roots on surface; many very fine, and common coarse, medium and fine
roots; smooth clear boundary.
AE—11 to 25 cm; pale brown (10YR 6/3; no change dry) sand; weak coarse blocky structure; very friable; many
very fine, and common coarse, medium and fine roots; few hollow old root casings with hard exteriors; smooth
clear boundary.
E—25 to 38 cm; light yellowish brown (10YR 6/4; 10YR 7/4 dry) sand; loose, single grain; many very fine, and
common coarse, medium and fine roots; smooth gradual boundary.
BE—38 to 55 cm; brownish yellow (10YR 6/6; 10YR 7/5 dry) sand; loose, single grain; few coarse, medium, fine,
and very fine roots; smooth gradual boundary.
B—55 to 140+ cm; brownish yellow (10YR 6/7; 10YR 7/6 dry) sand; loose, single grain; few coarse, medium, fine,
and very fine roots.
Profile: Bassendean Profile
Classification:
Profile location:
UTM:
Date and season:
Elevation:
Slope and site position:
Soil moisture regime:
Soil temperature regime:
Parent material:
Vegetation:
Drainage:
Surface features:
Faunal activity:
Coarse fragments:
Rooting depth:
Notes:
Diagnostic horizons and features:
ENTISOL: Thermic, Xeric Quartzipsamments
Close to plot BL4
50J 0318055 6659016
13 August 2012; late wet season
67 m above sea level
Flat
Xeric
Thermic
Bassendean sand
Banksias ~2-3 m high over shrubby vegetation
Well drained (water table at 3.2 m)
Shallow layer of dry leaves (~75%)
None observed
None
Throughout the profile to >165 cm
Color values are for moist soil and textures are field textures
(i) Ochric epipedon
(ii) Xeric moisture regime
(iii) >90% quartz in the particle control section
Horizon description
O—0 to 3 cm; very dark brown (10YR 2/2) organic-rich, root rich, mat-like horizon; many very fine, fine, medium
and coarse roots, including many clusters; few quartz grains; smooth abrupt boundary.
A—3 to 30 cm; very dark grey (2.5Y 3/1; 2.5 or 10YR 5/1 dry) loamy sand; weak blocky structure; very friable;
common medium and coarse, and many very fine and fine roots; smooth gradual boundary.
E1—30 to 70 cm; light grey (2.5Y 7/1; no change dry) sand; single grain; common coarse and very fine, and few
medium and fine roots; smooth diffuse boundary.
E2—70 to 320 cm; white (2.5Y 8/1; 2.5Y 9/1 dry) sand; single grain; few medium and coarse, and very few fine and
very fine roots; smooth diffuse boundary.
B—320+ cm; very pale brown (10YR 7/3 dry) sand; saturated (water table at 320 cm).