Biogeochemical Cycles

• Earth’s spheres overlap and interconnect.

• For example, water can be found in all spheres, not just the hydrosphere. Similarly, air can be found in all spheres, not just the atmosphere.

• Matter moves within and between spheres in biogeochemical cycles.

• Examples of biogeochemical cycles include:

• The water cycle.

• The carbon cycle.

• The nitrogen cycle.

• The oxygen cycle.

• The rock cycle.

Matter moves through the lithosphere, hydrosphere, atmosphere and biosphere in biogeochemical cycles.

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• The timescales involved in biogeochemical cycles varies depending on the substance being cycled and the part of the cycle in which it is generated.

• For example, the movement of carbon from the atmosphere to plants and animals is a relative fast process compared to formation of fossil fuels from dead plants and animals.

• Biogeochemical cycles therefore involve materials that are classified as renewable resources and those that are classified as non-renewable resources.

• For example, surface water and atmospheric oxygen are both regenerated over relatively short time periods and are therefore classified as renewable resources, whereas rocks and fossil fuels are regenerated over long periods of time and are therefore classified as non-renewable resources.

Biogeochemical cycles, such as the carbon cycle, include processes that occur over a range of timescales.

(Image: VectorMine, Adobe Stock)