Answer:
They are reservoirs of carbon in the carbon cycle.
Explanation:
A biogeochemical or nutrient cycle has two major components:
- the reservoirs of the biogeochemical or nutrient, and
- the processes involved in cycling the biogeochemical or nutrient between the reservoirs.
Air is a reservoir of largely inorganic carbon (as carbon dioxide) while water and soils are reservoirs of both organic (e.g. dead decomposing organisms and hydrocarbons) and inorganic forms of carbon (e.g. carbon-containing minerals such as limestone, calcium carbonate).
