What is a biogeochemical cycle? What is the role of the reservoir in a biogeochemical cycle? Give an example of a sedimentary cycle with a reservoir located in the Earth's crust.

(N/A) biogeochemical cycle is the movement of nutrients and other elements between biotic (living) and abiotic (non-living) components of the ecosystem.
The reservoir acts as a storage site for nutrients to meet the deficit which occurs due to an imbalance in the rate of influx and efflux. It ensures the continuous availability of essential nutrients for biological processes.
An example of a sedimentary cycle is the phosphorus cycle. In this cycle,the reservoir is the Earth's crust,specifically in the form of phosphate rocks.