the three representative profiles (Oderteich, Elend, and Guentersberg); all other
chemical analyses were conducted for all profiles. An energy dispersion X-ray
fluorescence micro-analyzer, EDX (JSX-3201; JEOL, Tokyo, Japan) was used to
determine soil chemical composition. The total carbon and nitrogen contents were
measured by the dry combustion method using a NC-analyzer (NC-80: Sumica
Bunseki Center, Osaka, Japan). Soil pH values in H 2 O, KCl, and NaF were measured by using the glass electrode method on soil suspended in 2.5 (H 2 O, KCl) or
50 (NaF) times volume of H 2 O, 1 mol L
À1 KCl, and 1 mol L
À1 NaF, respectively.
The CEC was determined according to the semi-micro Scholenberger method.
Exchangeable bases, expressed in cmolc kg
À1 soil, were determined using an atomic
absorbance spectrophotometer (AA-6400, Shimadzu Corp., Kyoto, Japan) on a soil
sample extracted with 1 mol L
À1 ammonium acetate (CH 3 COONH 4 ) at pH 7. Base
saturation (%) was calculated from CEC values and total amount of exchangeable
bases. Quantitative analysis of free oxides (Al, Fe, Si) was carried out by using the
selective dissolution method (Blakemore et al. 1987). Contents of Al, Fe, and Si,
extracted by shaking for 4 h in the dark in acid oxalate reagent (pH 3; Al o , Fe o , Si o ),
and contents of Al and Fe, extracted by shaking for 16 h in sodium pyrophosphate
(Al p , Fe p ), were measured using an atomic absorbance spectrophotometer
(AA-6400, Shimadzu Corp.). The Al Ex content was determined using an extract
prepared with 1 mol L
À1 KCl, according to the method of Blakemore et al. (1987).
Humus composition was determined by using the procedure proposed by Kumada
et al. (1967). Free and combined humic acids (HA) were extracted using 1 M NaOH
or 1 M Na 4 P 2 O 7 , respectively, and their colorimetric properties were measured by
using a UV spectrophotometer (UV 2400, Shimadzu Corp.).
10.1.2.5 Mineral Analysis
Mineral composition was determined by using an X-ray diffractometer (Rigaku
miniflex, Tokyo, Japan) under CuKα radiation conditions (30 kV, 15 mA). X-ray
diffraction patterns for the clay fraction were obtained on untreated, dithionitecitrate-bicarbonate-treated, magnesium-treated, ethylene glycol-treated, potassiumtreated, and K-saturated samples heated to 550
C from 3 to 30
at 2θ.
10.1.2.6 Soil Ergosterol Analysis
Ergosterol is used as a marker of living fungal biomass (Grant and West 1986;
Montgomery et al. 2000). The ergosterol content of each soil sample was determined
to examine the relationship between fungal biomass and sclerotium grain density.
Soil ergosterol was extracted by using the microwave-assisted method of
Montgomery et al. (2000) and determined by high-performance liquid chromatography, using a system composed of a pump (CCPE-II, Tosoh, Tokyo, Japan), an
injector (7125, Rheodyne, Bensheim, Germany), a UV detector (UV-8000, Tosoh,
Tokyo, Japan) operating at 282 nm, and an octadecylsilyl column (100 Â 4.6 mm,
10 Spatial Distribution of Sclerotia Grains in Low-pH Forest Soils, Central Germany
177
chemical analyses were conducted for all profiles. An energy dispersion X-ray
fluorescence micro-analyzer, EDX (JSX-3201; JEOL, Tokyo, Japan) was used to
determine soil chemical composition. The total carbon and nitrogen contents were
measured by the dry combustion method using a NC-analyzer (NC-80: Sumica
Bunseki Center, Osaka, Japan). Soil pH values in H 2 O, KCl, and NaF were measured by using the glass electrode method on soil suspended in 2.5 (H 2 O, KCl) or
50 (NaF) times volume of H 2 O, 1 mol L
À1 KCl, and 1 mol L
À1 NaF, respectively.
The CEC was determined according to the semi-micro Scholenberger method.
Exchangeable bases, expressed in cmolc kg
À1 soil, were determined using an atomic
absorbance spectrophotometer (AA-6400, Shimadzu Corp., Kyoto, Japan) on a soil
sample extracted with 1 mol L
À1 ammonium acetate (CH 3 COONH 4 ) at pH 7. Base
saturation (%) was calculated from CEC values and total amount of exchangeable
bases. Quantitative analysis of free oxides (Al, Fe, Si) was carried out by using the
selective dissolution method (Blakemore et al. 1987). Contents of Al, Fe, and Si,
extracted by shaking for 4 h in the dark in acid oxalate reagent (pH 3; Al o , Fe o , Si o ),
and contents of Al and Fe, extracted by shaking for 16 h in sodium pyrophosphate
(Al p , Fe p ), were measured using an atomic absorbance spectrophotometer
(AA-6400, Shimadzu Corp.). The Al Ex content was determined using an extract
prepared with 1 mol L
À1 KCl, according to the method of Blakemore et al. (1987).
Humus composition was determined by using the procedure proposed by Kumada
et al. (1967). Free and combined humic acids (HA) were extracted using 1 M NaOH
or 1 M Na 4 P 2 O 7 , respectively, and their colorimetric properties were measured by
using a UV spectrophotometer (UV 2400, Shimadzu Corp.).
10.1.2.5 Mineral Analysis
Mineral composition was determined by using an X-ray diffractometer (Rigaku
miniflex, Tokyo, Japan) under CuKα radiation conditions (30 kV, 15 mA). X-ray
diffraction patterns for the clay fraction were obtained on untreated, dithionitecitrate-bicarbonate-treated, magnesium-treated, ethylene glycol-treated, potassiumtreated, and K-saturated samples heated to 550
C from 3 to 30
at 2θ.
10.1.2.6 Soil Ergosterol Analysis
Ergosterol is used as a marker of living fungal biomass (Grant and West 1986;
Montgomery et al. 2000). The ergosterol content of each soil sample was determined
to examine the relationship between fungal biomass and sclerotium grain density.
Soil ergosterol was extracted by using the microwave-assisted method of
Montgomery et al. (2000) and determined by high-performance liquid chromatography, using a system composed of a pump (CCPE-II, Tosoh, Tokyo, Japan), an
injector (7125, Rheodyne, Bensheim, Germany), a UV detector (UV-8000, Tosoh,
Tokyo, Japan) operating at 282 nm, and an octadecylsilyl column (100 Â 4.6 mm,
10 Spatial Distribution of Sclerotia Grains in Low-pH Forest Soils, Central Germany
177