Biogeochemical Cycles: Introduction and Importance

Natural pathways that move essential chemical elements between living organisms, the atmosphere, and Earth’s crust

Random weather patterns that change ecosystems seasonally

Human-engineered systems that transport nutrients between farms

Single-event processes that occur only during extreme climate events

It provides a medium, such as precipitation, that dissolves CO2 to form carbonic acid and carries nutrients, supporting the other cycles

It stores carbon permanently so it cannot enter the atmosphere

It removes nitrogen from soils and prevents it from reaching waterways

It operates independently and does not interact with other cycles

Photosynthesis and respiration

Denitrification only

Evaporation only

Plate tectonics

The process by which nitrogen moves from the atmosphere to the soil, and then to living organisms

The movement of carbon through living organisms and the atmosphere

The continuous movement of water on, above, and below Earth’s surface

The permanent storage of nitrogen in rocks

They keep essential elements available, shape ecosystems by influencing nutrient availability and function, and show how resources are recycled repeatedly

They increase Earth’s temperature by trapping heat in the atmosphere

They prevent any movement of elements between living and non-living parts

They eliminate the need for organisms to obtain nutrients

Water cycle—continuous movement of water; Carbon cycle—movement of carbon through organisms and the atmosphere; Nitrogen cycle—nitrogen from atmosphere to soil to organisms

Water cycle—permanent storage of water in oceans; Carbon cycle—release of carbon only during volcanic eruptions; Nitrogen cycle—nitrogen remains only in the atmosphere

Water cycle—movement of water only above Earth’s surface; Carbon cycle—no linkage to living organisms; Nitrogen cycle—transfer only within soils

Water cycle—evaporation stops nutrient transport; Carbon cycle—photosynthesis not involved; Nitrogen cycle—leaching never occurs

Precipitation leaching nutrients into waterways

Geologic burial preventing any nutrient movement

Atmospheric CO2 remaining isolated from water

Ocean water never interacting with land processes

Water dissolves gases like CO2 and transports nutrients, linking carbon and nitrogen cycles.

Water only stores heat and does not interact chemically with carbon or nitrogen.

Water prevents precipitation from carrying substances from the atmosphere to Earth’s surface.

Water blocks leaching of nutrients from soil into rivers and oceans.

Plants use water, carbon dioxide, and nitrogen to create organic matter.

Plants release carbon dioxide and nitrogen gas while absorbing only water.

Plants rely exclusively on nitrogen gas to form glucose.

Plants use water to remove carbon dioxide from the atmosphere without involving nitrogen.

Respiration by plants and animals

Photosynthesis in leaves

Nitrogen fixation by bacteria

Precipitation from clouds