What is a biogeochemical cycle?

A biogeochemical cycle refers specifically to the movement of elements and compounds through various biotic (living organisms) and abiotic (environmental) components of the Earth. This process encompasses the flow of essential substances such as carbon, nitrogen, phosphorus, and water among the atmosphere, lithosphere, hydrosphere, and biosphere.

In ecological terms, these cycles are crucial for maintaining the balance of nutrients in an ecosystem, supporting life by ensuring that essential elements are available for biological processes. For example, in the carbon cycle, carbon dioxide from the atmosphere is utilized by plants during photosynthesis, which then become part of the food web as animals consume them. Eventually, carbon is returned to the atmosphere through respiration and decomposition.

The other options focus on narrower or different concepts: the movement of water is specifically tied to the water cycle, changes of seasons relate to climatic patterns rather than nutrient movement, and energy transfer from the sun describes energy flow, which is separate from the material cycles that biogeochemical cycles address.