10.1.3.2 Content of Sclerotia Grains and Soil Ergosterol
Figure 10.2 shows the spatial distribution of sclerotia grains along an eastward
transect from Mt. Brocken. Sclerotia grain content is represented as grain weight
per soil weight (g kg
À1 ). In the A, E, and B horizons, the values were 0–4.99 g kg
À1 ,
0–0.93 g kg
À1 , and 0–0.31 g kg
À1 , respectively. The largest content was observed in
the A2 horizon of the Sorge soil. Across the transect, content decreased in the
leeward (eastward) direction. The boundary between sclerotia-containing soil and
sclerotia-free soil was near Allrode, about 30 km east of Mt. Brocken.
10.1.3.3 Relationship Between Soil Properties and Sclerotia Grains
Soil ergosterol content tended to harmonize with sclerotia grain content in the
ergosterol-rich soil profiles at Brandhai, Sorge, and Allrode (Fig. 10.4). However,
sclerotia content was small in the ergosterol-rich Heinrichsburg soil profile.
The pH (KCl) values and Al Ex content for Horizons A and E for all 12 profiles
differed by soil types. Haplic Podzols (Podsole) and Dystric Cambisols (BraunerdePodsole) both had low pH values, but the exchangeable Al (Al
3+ ) content was higher
in Haplic Podzols. Albic Luvisols (Braunfahlerde) had higher pH, with a wide range
of Al Ex content. It was recognized that the relationship between Al Ex content and pH
(KCl) value is not clear for soils that with pH (KCl) < 4. The free oxide composition
and clay mineral composition of the three representative profiles (Tables 10.2 and
10.3) indicate that a strong leaching process migrated aluminum colloids from the
surface layers of both Podsole and Braunerde-Podsole. Furthermore, past lessivage
likely induced clay destruction in the Braunerde-Podsole. This process may also be
responsible for the properties of the Hohe Warte soil (Braunfahlerde), having low pH
and low Al Ex content. The pH (KCl), Al o , Al p , and Al
3+ content of Hohe Warte soil
were 3.85 g kg
À1 , 3.09 g kg
À1 , 1.88 g kg
À1 , and 0.21 g kg
À1 , respectively, indicating
that the low Al Ex content under low pH conditions is related to the low content of
active aluminum in the form of humus-Al complexes (Al p ). Volcanic glass particles
were observed by microscopy in Elend soil, and the pH (NaF) value was >9.5.
Further investigation is required to determine whether tephric material is the origin
of the free aluminum in the Elend soil, which had a relatively large sclerotia grain
content.
Figure 10.5 shows the relationship of Al p /Al o to Al Ex content, combined with
sclerotia grain density. With the exception of the Bs horizons of the Podzols
(Podsole), which were less than 10 cm from the surface, the content of sclerotia
grains was relatively high in soil samples with an Al p /Al o value >0.7 and an Al
3+
content >0.54 g kg
À1 (6 cmolc kg
À1 ). Soil samples from Guentersberg (Dystric
Cambisols/Braunerde-Podsole), Heinrichsburg (Dystric Cambisols/BraunerdePodsole), and Hohe Warte (Albic Luvisols/Braunfahlerde), in which few sclerotia
grains were detected, were clearly excluded from the area (Al p /Al o ratio > 0.7, Al
3+
content > 0.54 g kg
À1 ) described in Fig. 10.5.
182
M. Watanabe and N. Sakagami
Figure 10.2 shows the spatial distribution of sclerotia grains along an eastward
transect from Mt. Brocken. Sclerotia grain content is represented as grain weight
per soil weight (g kg
À1 ). In the A, E, and B horizons, the values were 0–4.99 g kg
À1 ,
0–0.93 g kg
À1 , and 0–0.31 g kg
À1 , respectively. The largest content was observed in
the A2 horizon of the Sorge soil. Across the transect, content decreased in the
leeward (eastward) direction. The boundary between sclerotia-containing soil and
sclerotia-free soil was near Allrode, about 30 km east of Mt. Brocken.
10.1.3.3 Relationship Between Soil Properties and Sclerotia Grains
Soil ergosterol content tended to harmonize with sclerotia grain content in the
ergosterol-rich soil profiles at Brandhai, Sorge, and Allrode (Fig. 10.4). However,
sclerotia content was small in the ergosterol-rich Heinrichsburg soil profile.
The pH (KCl) values and Al Ex content for Horizons A and E for all 12 profiles
differed by soil types. Haplic Podzols (Podsole) and Dystric Cambisols (BraunerdePodsole) both had low pH values, but the exchangeable Al (Al
3+ ) content was higher
in Haplic Podzols. Albic Luvisols (Braunfahlerde) had higher pH, with a wide range
of Al Ex content. It was recognized that the relationship between Al Ex content and pH
(KCl) value is not clear for soils that with pH (KCl) < 4. The free oxide composition
and clay mineral composition of the three representative profiles (Tables 10.2 and
10.3) indicate that a strong leaching process migrated aluminum colloids from the
surface layers of both Podsole and Braunerde-Podsole. Furthermore, past lessivage
likely induced clay destruction in the Braunerde-Podsole. This process may also be
responsible for the properties of the Hohe Warte soil (Braunfahlerde), having low pH
and low Al Ex content. The pH (KCl), Al o , Al p , and Al
3+ content of Hohe Warte soil
were 3.85 g kg
À1 , 3.09 g kg
À1 , 1.88 g kg
À1 , and 0.21 g kg
À1 , respectively, indicating
that the low Al Ex content under low pH conditions is related to the low content of
active aluminum in the form of humus-Al complexes (Al p ). Volcanic glass particles
were observed by microscopy in Elend soil, and the pH (NaF) value was >9.5.
Further investigation is required to determine whether tephric material is the origin
of the free aluminum in the Elend soil, which had a relatively large sclerotia grain
content.
Figure 10.5 shows the relationship of Al p /Al o to Al Ex content, combined with
sclerotia grain density. With the exception of the Bs horizons of the Podzols
(Podsole), which were less than 10 cm from the surface, the content of sclerotia
grains was relatively high in soil samples with an Al p /Al o value >0.7 and an Al
3+
content >0.54 g kg
À1 (6 cmolc kg
À1 ). Soil samples from Guentersberg (Dystric
Cambisols/Braunerde-Podsole), Heinrichsburg (Dystric Cambisols/BraunerdePodsole), and Hohe Warte (Albic Luvisols/Braunfahlerde), in which few sclerotia
grains were detected, were clearly excluded from the area (Al p /Al o ratio > 0.7, Al
3+
content > 0.54 g kg
À1 ) described in Fig. 10.5.
182
M. Watanabe and N. Sakagami