Biosphere- Soils

Question 1

Biosphere

Answer 1

The part of the Earth and it’s atmosphere in which living organisms exist or where life could be supported
Sometimes referred to as the zone of life

Question 2

Key components of a soil

Answer 2

• weathered rock/ material matter that is inorganic and which is based on broken-down bedrock
• water and air
• soil biota (micro organisms, soil animals, plants living all/ most of life in soil, decayed organic matter)

Question 3

Humus

Answer 3

Decomposed organic matter
i.e. leaf litter, animal manure, decomposed flora and fauna
It is rich in nutrients so increases soil fertility

Question 4

Catena

Answer 4

A sequence of different soil profiles that occur down a slope

Question 5

Regolith

Answer 5

Loose unconsolidated material that sits atop a layer of bedrock
Derived from weathered bedrock

Question 6

Inorganic matter

Answer 6

Any compound that is not an organisms compound; it is composed of sand, silt and clay

Question 7

Salinisation

Answer 7

Evapotranspiration exceeds precipitation so salts are drawn upwards in solution
Further evaporation results in the deposition of salt as a hard crust

Question 8

Weathering

Answer 8

In situ breakdown of parent material (rock) into small grains and soil

Question 9

Podzilisation

Answer 9

Intense leaching, most common in cool climates where precipitation greatly exceeds evapotranspiration and where soils are well drained or sandy

Question 10

Calcification

Answer 10

Low levels of leaching (precipitation is equal/ slightly higher than evapotranspiration) therefore leaching is unable to remove calcium which subsequently builds up in the B horizon

Question 11

Gleying

Answer 11

Occurs when the output of water from a soil profile is restricted giving waterlogged and anaerobic conditions

Question 12

Leaching

Answer 12

Wherever rainfall exceeds evaporation and there is a free downward movement of water, soluble minerals are removed from the soil profile

Question 13

Podzolisation

Answer 13

Wherever rainfall significantly exceeds evapotranspiration and there is (sandy wall drained through the soil) free downward movement of water through the soil pore system, soluble minerals are dissolved by rainfall (weak carbonic acid) and then removed from the upper horizons by percolating soil water.

Question 14

Eluviation

Answer 14

The removal of minerals from the soil layer

Question 15

Illuviation

Answer 15

The buildup of minerals in the soil layer