podsol

• spatial distribution

  Soil of Taiga Biome - vast continious belt across North America , Europe and Asia between Tundra to the North and temperature grasslands to the South
• classification of soil

  zonal (mature soil)
• climatic conditions and influence on the soils

  • needs a downwards flow of water - precipitation is low but due to cool temperatures , precipitation exceeds evapotranspiration
  • confierous trees shelter ground from drying winds which preserve soil moisture
• why is the nutrient cycle poor in the podsol soils?

  evergreen trees don't absorb calcium , magnesium or potassium so falling leaves don't return these to soil making the nutrient cycle poor
• vegetation

  coniferous evergreen : Spruce , Fir and Pine
• how is the soil used by humans?

  mainly used for commercial forestry plantations - in the UK it's associated with upland sheep farming and heather moorland (managed with controlled burning for the breeding of grouse). Grouse shooting employs 2500 people and generates £150m annually
• the soil is acidic from coniferous trees
• why is arable farming difficult?

  • lack of nutrients due to acidity
  • formation of iron-pan in B layer = waterlogging. Makes ploughing difficult as machines sink into ground
  • arable farming can take place but requires treatment with lime to reduce acidity
• consequence of acid in soil

  water travelling through soil is more difficult to dissolve iron minerals