Biosphere

Question 1

1.a)Brown earths

Answer 1

• deep leaf litter layer - deciduous forest - warm climates - south facing - fertile
• soil biota - quickly - mildly acidic humus
• mixing - excrete - bodies - blurred soil horizons
• recycling of minerals - rich litter layer - dark brown colour - leaching of iron - reddish brown
• no iron pan - lower rainfall areas - very thin iron pan - high rainfall, an acidic humus and well drained soils
• deep and fertile - chemical and biological weathering - limestone - lighter coloured alkaline soils - clay - dark coloured soil

Question 2

1.b)Podzol

Answer 2

• thin acidic litter layer - pine needles - cool climates - heavy rainfall - infertile
• cold climate and acidic conditions - soil bio-activity - very distinct soil horizons
• rainfall - ash grey colour - evapotranspiration and capillary action
• spring, ice/snow melts - slopes - pronounced ash grey colour
• iron pan - leaches iron - waterlogging
• thin - slow rate of weathering - infertile - acidic

Question 3

1.c)Gley soils

Answer 3

• very thin litter layer - little vegetation - low levels of soil biota - infertile
• mossed and lichens - waterlogged - acidic humus
• waterlogged - permafrost - flat land
• waterlogging - partially decomposed material - dark coloured A horizon
• B horizon is blue/grey - oxygen - iron compounds
• parent material - freeze thaw action - soil heave

Question 4

2. Differences between brown earth and podzol

Answer 4

• brown earths have deepER litter layer because …(same explanation as in original question)
• podzol- thinnER acidic litter later than brown earth because …
• brown earths- blurred soil horizons because…
• podzol- MORE distinct soil horizons because …
• brown earths- dark brown and reddish/brown colour because …
• podzol- ash grey and pronounced ash grey colour because …