Biogeochemical cycles

Question 1

Biogeochemical

Answer 1

Bio refers to the biosphere. Geo refers collectively to the lithosphere, atmosphere, and hydrosphere. Chemical refers to the chemicals that go through the cycle.

Question 2

Biogeochemical cycle

Answer 2

A circuit or pathway by which a chemical element or molecule moves through both biotic (“bio-“) and abiotic (“geo-“) compartments of an ecosystem.

Question 3

Gas cycle

Answer 3

Elements move through the atmosphere. Main reservoirs are the atmosphere and the ocean. Eg Carbon, nitrogen and oxygen

Question 4

Sedimentary cycle

Answer 4

Elements move from land to water to sediment. Main reservoirs are the soil and sedimentary rocks. Eg Phosphorous and sulfur

Question 5

Advantages of cycles

Answer 5

For remediation of organic & metal pollutants. For recovery of precious metals such as Cu or U from low grade ores.

Question 6

Disadvantages of cycle

Answer 6

Formation of acid rain & acid mine drainage. Metal corrosion process. Formation of nitrous oxide which can deplete earth’s ozone layer.

Question 7

Gaia hypothesis

Answer 7

Earth behave like a superorganism. “Living organisms & their material environment are tightly coupled. The coupled system is a superorganism, & as it evolves, there emerges a new property, the ability to self regulate climate & chemistry”.

Question 8

Soil respiration

Answer 8

Soil respiration represents decomposition of organic residues, root respiration, and slow decay of soil organic matter (SOM).