Podsol.

• The zonal soil of the taigas that stretch across North American and Eurasia. Vegetation are restricted to boreal coniferous forest as a result of prolonged harsh winters and cool summers. Also found in cool climates such as the UK on moors and heathlands as well as areas of sandy soil such as fluvioglacial outwash plains.
• Associated with coniferous evergreen trees such as spruce, fir and pine. As boreal areas do not receive heavy rainfall the:

  podsolisation process requires a general downward movement of water through the soil.

  • As precipitation exceeds evapotranspiration because of low temps.
• Forest vegetation influences soil moisture balance:

  • coniferous trees shelter the ground from drying winds.
  • moderate precipitation provides a surplus and allows downward infiltration and percolation.
• Poor nutrient cycle:

  • coniferous evergreens don't take up elements such as calcium, magnesium and potassium meaning nutrients not returned to soil upon falling of needles - mor humus (acidic).
• Characteristics of Podsol:

  • accumulation of hard pan iron beneath the zone of leaching and marking the highest point of the water table.
  • clear differentiation of horizons indicating, in contrast to TRL may be fewer mixing agents such as earthworms and ants.
• UK:

  • associated with upland sheep farming and heather moorland managed with controlled burning for the breeding of grouse for shooting.
  • small areas of heather burn off in a 10-15 year rotation -each square km has 6 burning patches resulting in patchwork pattern of of heather at various stages of regrowth.
  • feeding area for grouse with unburnt nesting cover nearby.
  • employs 2500 people and generates £150 mil annually -importance to UK's rural economy cannot one overstated.
• Taiga in Eurasia now disappearing due to commercial farming in Russia since fall of USSR.
• Logging in North America is now managed.