Final answer:
A flux in a biogeochemical cycle is the flow of an element into a reservoir of the cycle, representing the movement of elements between different parts of the cycle.
Step-by-step explanation:
A flux in a biogeochemical cycle refers to the flow of an element into a reservoir of the cycle. It represents the movement of elements such as carbon, nitrogen, or phosphorus between different parts of the cycle. For example, in the carbon cycle, the flux of carbon dioxide into the atmosphere from cellular respiration is one of the processes that contribute to the overall balance of carbon.
Learn more about Biogeochemical cycles