Natural Resources Notes

• Biogeochemical cycles refer to the flow of chemical elements and compounds between living organisms and the physical environment.
• It is defined as a constant interaction between the biotic and abiotic components of the biosphere in terms of matter and energy so as to maintain a balance in the environment.
• This is possible due to biological, physical and chemical activities in our surrounding.
• Chemicals absorbed or ingested by organisms are passed through the food chain and returned to the soil, air, and water by mechanisms like respiration, excretion, and decomposition.

• Water cycle is defined as a constant interaction between biotic and abiotic components to maintain the level of different forms of water in the environment to support life.
• Or, it can also be defined as a series of processes in which water evaporates and falls on the land as rain and later flows back into the sea via rivers. It is also known as hydrological cycle.

Occurrence:

• Water can exist in different states in different regions of our environment.

• Nitrogen cycle is the constant interaction between biotic and a biotic components of the earth to circulate the nitrogen in atmosphere, lithosphere, hydrosphere and biosphere in different forms.

Occurrence: