A podzolic soil

Soils

Soil formation has continued throughout the Holocene (Nethersole-Thomson and Watson, 1981). The acidic granite and schist and the free-draining glacial and meltwater sediments derived from them have encouraged the formation of podzolic soils at all level. Richer soils are largely confined to valley sites where brown earths are developed, especially on finer grained river sediments.

 

Organic soils or peat develop at poorly-drained, low angle sites. Once the humus layer reaches a thickness of ~30 cm the roots of the vegetation no longer reach the mineral soil below. Few plants can tolerate the wet and acid conditions and a blanket bog develops. A fine example occurs on the flat-topped terraces in Gleann Einich. Here the sphagnum bog contains many pools that can be probed by hand to recover the partially decayed vegetation.

 

The soil of the Rothiemurchus pine woods is a classic podzol. A felted layer of recently fallen pine needles rests on black humus. The underlying gravel or sand is bleached due to the leaching of Fe and other solutes. A secondary humic layer may exist at a depth of 30-60 cm, resting above a red brown to black layer of Fe cementation, termed the 'iron pan'.

 

On the plateau, the continual disturbance by wind, frost and man means that soil development is negligible at many exposed sites. Clear signs of the formation of thin alpine podzols are evident however at vegetated sites, where an upper organic horizon on which the plants are growing rests on a zone depleted in iron and a lowermost layer enriched in Fe and organic matter.