Olf
Of transition horizon (Ol-Of), in which the macroscopically detectable needle and leaf debris predominates over the organic fine matter (Figure 7b).
[l from litter]

1. organic carbon content ≥ 15 mass % and
2. developed under aeromorphic to aero-hydromorphic conditions
3. Proportion of organic fine matter 10 – < 30 vol.%

Olf horizont, leaf material: common beech (Fagus sylvatica) with fungus mycelium,           © Jan Evers

(-> L Mull-like F Mull)

Ohf
Of transition horizon (Oh-Of) with a high to predominant proportion of organic fine matter and lower proportions of macroscopically recognisable remains of dead plant biomass/litter (Figure 7c).
[h from humified]

1. organic carbon content ≥ 15 mass % and
2. developed under aeromorphic to aero-hydromorphic conditions
3. Proportion of organic fine matter 30 – < 70 vol.%

Ohf horizon, leaf material: common beech (Fagus sylvatica) © Gerhard Milbert

Ohf horizont, leaf material: common beech (Fagus sylvatica)
© Gerhard Milbert

(-> Moder-like F-Mull)

Odf
Of modified horizon with root felt.
[d from „stark durchwurzelt“ (german for strong rooting)]

1. organic carbon content ≥ 15 mass % and
2. developed under aeromorphic to aero-hydromorphic conditions
3. Proportion of living fine roots ≥ 50 vol.%

(-> Rhizo F Mull)

Owf
Of modified horizon, temporarily influenced by stagnic water or groundwater. Vegetation indicates wetness in the A horizon (Figure 14).
[w from water influenced]

1. organic carbon content ≥ 15 mass % and
2. developed under aeromorphic to aero-hydromorphic conditions
3. Proportion of living fine roots ≥ 50 vol.%
4. temporarily anaerobic conditions and
5. grey to black colouring of the litter and
6. above recently water influenced hydromorphic A or H horizon

(->Moist F Mull)

Ol-horizon, leaf material: common oak (Quercus robur) on top of a hydromorphic  Owf horizon,
© Gerhard Milbert