Gley

EXPLAIN

DRAWN DIAGRAM

DESCRIPTION

image

C

A/B

AO

Associated vegetation is small shrubs and lichens. ✔

Thin black humus layer. ✔

Acidic mor humus, pH 3.5-4. ✔

Clearly defined horizons. ✔

A and B horizons are blue/grey. ✔

Red mottling in the A/B horizons. ✔

Very few soil organisms to mix soil. ✔

Permafrost in C horizon. ✔

The parent material in the C-horizon is weathered rock. ✔

AO

A/B

C

  • Limited vegetation produces a thin acidic mor humus. ✔
  • Low temperatures cause a slow rate of decomposition. ✔
  • Shallow roots limit recycling of minerals back to the vegetation. ✔
  • Cold temperatures/waterlogging means few organisms can survive. ✔
  • Lack of organisms means clearly defined horizons. ✔
  • Soil has a blue grey colour due to anaerobic conditions. ✔
  • Heavy precipitation causes waterlogging. ✔
  • Waterlogged soil creates anaerobic conditions. ✔
  • This means that iron compounds are changed from red brown to blue ✔ due to oxygen being extracted by microorganisms (gleying). ✔
  • Burrowing animals/soil drying out in summer leave oxygen pockets. ✔
  • This allows re-oxygenation or iron. ✔
  • It causes the soil to have a red mottling effect. ✔
  • Sometimes this is brought up by soil heave and may breach the surface. ✔
  • Found on flat surfaces which means water cannot drain away. ✔
  • Impermeable clay impedes drainage and causes waterlogging. ✔