The movement of any material from one place to another is called a flux and we typically think of a carbon flux as a transfer of carbon from one pool to another. Fluxes are usually expressed as a rate with units of an amount of some substance being transferred over a certain period of time.
So the flux is dependent on the type of mass (plant or animal) and the process of change it grows. You can not really estimate the carbon flux without considering these matters.
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