The cycling of elements in an ecosystem is called

The cycling of elements in an ecosystem is called Biogeochemical cycle.
A biogeochemical cycle is the pathway by which a chemical substance cycles the biotic and the abiotic compartments of Earth. The biotic compartment is the biosphere and the abiotic compartments are the atmosphere, hydrosphere and lithosphere.
Energy flows directionally through ecosystems, entering as sunlight (or inorganic molecules for chemoautotrophs) and leaving as heat during the many transfers between trophic levels.