Textbook - Chapter 4: The Terrestrial Environment

Question 1

Available water capacity

Answer 1

Supply of water available to plants in well-drained soil

Question 2

Anion

Answer 2

Ion carrying a negative charge

Question 3

A horizon

Answer 3

Surface stratum of mineral soil, characterized by maximum accumulation of organic matter, maximum biological activity and loss of such materials as ion, aluminum oxides and clays

Question 4

B Horizon

Answer 4

Soil stratum beneath the A horizon, chafacterized by an accumulation of silica, clay and iron and aluminum oxides and possessing block or prismatic structure.

Question 5

C Horizon

Answer 5

Soil stratum beneath the solum (A and B horizons) little affected by boligical activity or soil forming processes.

Question 6

Calcification

Answer 6

Process of soil formation characterized by accumulation of calcium in lower horizons

Question 7

Capillary Water

Answer 7

That portion of water int he soil held by capillary forces between soil particles

Question 8

Cation

Answer 8

Part of a dissociated molecule carrying a positive electrical charge

Question 9

Cation exchange capacity (CEC)

Answer 9

Ability of a soil particle to absorb positively charged ions

Question 10

Chemical weathering

Answer 10

The action of a set of chemical processes such as oxidation, hydrolysis, and reduction operating at the atomic and molecular level that break down and re-form rocks and minerals

Question 11

Colloid

Answer 11

Negatively charged particles in the soil that provide surfaces with high cation exchange capacity

Question 12

Field capacity

Answer 12

Amount of water held by soil against the force of gravity

Question 13

Gleization

Answer 13

A process in waterlogged soils in which iron because of an inadequate supply of oxygen, is reduced to a ferrous compound, giving dull gray or bluish mottles and color to the horizons

Question 14

Horizon

Answer 14

Major zone or layer of soil, with its own particular structure and characteristics

Question 15

Ion exchange capacity

Answer 15

Total number of charged sites on soil particles within a volume of soil

Question 16

Laterization

Answer 16

Soil-forming process in hot, humid climates, characterized by intense oxidation; results in loss of bases and in a deeply weathered soil composed of silica

Question 17

Leaching

Answer 17

Dissolving and washing of nutrients out of soil, litter and organic matter.

Question 18

Leaf area index

Answer 18

The total leaf area of a plant exposed to incoming light energy relative to the ground surface area beneath the plant

Question 19

Mechanical weathering

Answer 19

Breakdown of rocks and minerals in place by disintegration processes such as freezing and thawing.

Question 20

Parent material

Answer 20

The material from which soil develops

Question 21

Podzolization

Answer 21

Soil-forming process in which acid leaches the A horizon and iron, aluminium accumulate in lower horizons

Question 22

Regolith

Answer 22

The unconsolidated debris layer composed of exposed rock overlaying the hard, unweathered rock in most places on the Earth’s surface. It varies in depth from virtually nonexistent to tens of meters

Question 23

Soil profile

Answer 23

Distinctive layering of horizons in the soil

Question 24

Salinization

Answer 24

The process of accumulation of soluble salts in soil, usually by upward capillary movement from a salty groundwater source. Also called salination.

Question 25

Wilting point

Answer 25

Moisture content of soil at which plants wilt and fail to recover their turgidity when places in a dark, humid atmosphere; measured by oven drying

Question 26

Water balance

Answer 26

Maintenance of the balance of water between organisms and their surrounding environments