At perhaps the most fundamental level, distinction can be made between " mineral soil horizons " and " organic soil horizons ".
32.
Its sedimentary context in monospecific assemblages on immature paleosols, is evidence that it was an opportunistic pioneer plant that grew on mineral soils with little competition.
33.
It prefers damp mineral soils with a source of dim light, such as reflection from a pool, overturned tree roots, and entrances to animal burrows.
34.
In many cases the mineral soil is intentionally exposed, encouraging germination by providing a moister seedbed than the leaves and needles that normally cover the forest floor.
35.
Also, the much greater acidity under any forests inhibits the action of certain soil organisms that otherwise would mix much of the surface litter into the mineral soil.
36.
Field studies have shown that extramatrical mycelium is more likely to proliferate in mineral soils than in organic material, and may be particularly absent in fresh leaf litter.
37.
Soil organisms are hindered by high acidity, and most agricultural crops do best with mineral soils of pH 6.5 and organic soils of pH 5.5.
38.
The fresh marsh is located primarily on mineral soil and to a very limited extent, on flotons ( i . e ., floating mats of emergent vegetation ).
39.
The developing plant roots are associated with mycorrhizal fungi that assist in breaking up the porous lava, and by these means organic matter and a finer mineral soil accumulate with time.
40.
In an undisturbed forest, the mineral soil is protected by a layer of " leaf litter " and an " humus " that cover the forest floor.
