Biosphere

Question 1

Explain the factors that have affected the information on a Brown Earth Soil.

Answer 1

Due to warm temperatures, there’s rapid decomposition of organic material to form humus. There are lots of soil biota present. This helps mix the soil to produce undefined land. Brown Erath soil is well drained due to biota and vegetation they are well aerated. This provides soil with oxygen and bacteria to maintain nutrients. A small Iron pan forms however this is rare. Due to precipitation and evaporation occurring at similar rates, there is limited leaching. Leaching occurs to replenish the (A) Horizon with loamy soil texture and a lighter brown at (B) Horizon has minerals retained near the surface. Deciduous trees are the dominant vegetation growing above the ground. Plants have deep roots bringing minerals from subsoil and regolith to the surface via capillary action creating a zone of ELUVIATION. In the subsoil and a zone of ILLUVIATION in the (A) Horizon forms. The trees provide abundant leaf litter adding to the humification process, leaf litter decomposes to form a thick black layer of slight acidic humus.

Question 2

Explain the factors that have affected the formation of a Gley Soil.

Answer 2

It is formed in areas where water doesn’t drain away. Precipitation is greater than evaporation and therefore temperature is low. It is often waterlogged. Waterlogged areas do not allow the soil to oxygen. Organisms need oxygen to survive this limits the biota. This leads to minimal mixing and undefines horizons. Organisms left in soil extract oxygen because they need to survive, the IRON COMPOUNDS, and the soil gradually turn grey/blue as the oxygen is DEPLETED. In the absence of oxygen occurs then iron compounds exchange chemically from their usual color. Heavy leaching occurs through the soil creating a zone of ELUVOATION in the topsoil and an accumulation of iron and aluminum oxide in the subsoil which is a Zone of ILLUVIATION. Deposition TAKE place, an iron pan forms and impedes drainage and causes waterlogging in topsoil. Soils suffer from waterlogging due to spring meltwater. Due to low temperature, the breakdown of materials is very slow. Large chunks of glaciers are present in the subsoil. There’s also very slow humification in the topsoil creating a black thin layer of acidic humus. Due to the main vegetation being coniferous woodland.

Question 3

Explain the factors that have affected the formation of Podzol Soil.

Answer 3

Due to low temperatures in the Northern Latitudes, there’s a slow decomposition of organic material. This leads to thin soils and due to precipitation in the area being greater than evaporation due to climate there are high levels of leaching which is the downward movement of water through the soil. This drags minerals and nutrients such as aluminum and iron oxides from the (A) Horizon through the soil. The soil creates a zone of ELUVIATION in the (A) Horizon leaving the soil Ashy grey with a thin texture. Minerals move downwards the soil this creates a zone of ILLUVIATION in the (B) Horizon where minerals are deposited turning the layer reddish color and leading to the formation of an iron pan between the (A) and (B) Horizon. The iron pan may impede drainage through the soil due to its non-porous characteristics causing waterlogging. The steep relief of land also encourages increased leaching. The low temperature limits soil biota, animals, and organisms that live in the soil. This creates clear and defined horizons as there is no biota to mix the soil. Coniferous vegetation is the dominant vegetation resulting in abundant leaf litter made from coniferous needles which produce acidic MOR. It’s the slowest humification due to the cold temperature.
Its shallow roots of coniferous mean that there’s limited absorption of deep leached minerals capillary action.

Question 4

Draw a fully annotated soil profile of a PODZOL SOIL to show its main characteristics including the horizons, color, texture and drainage, and associated vegetation.

Answer 4

1. HORIZON
2. CLIMATE
3. BIOTA
4. VEGETATION
5. ELLUVIATION + ILLUVIATION
6. LEACHING + CAPILLARY ACTION
7. COLOUR
8. DRAINAGE
9. HUMUS
10. PRECIPITATION OVER EVAPORATION

Question 5

Draw a fully annotated soil profile of a BROWN EARTH SOIL to show its main characteristics including the horizon, color, texture, drainage, and associated vegetation.

Answer 5

1. HORIZON
2. CLIMATE
3. BIOTA
4. VEGETATION
5. ELLUVIATION + ILLUVIATION
6. LEACHING+ CAPILLARY ACTION
7. COLOUR
8. DRAINAGE
9. HUMUS
10. PRECIPITATION OVER EVAPORATION

Question 6

Draw a fully annotated soil profile of a GLEY SOIL to show its main characteristics including the horizon, color, texture, drainage, and associated vegetation.

Answer 6

1. HORIZON
2. CLIMATE
3. BIOTA
4. VEGETATION
5. ELLUVIATION
6. LEACHING + CAPILLARY ACTION
7. COLOUR
8. DRAINAGE
9. HUMUS
   10.