What is a biogeochemical cycle. What is the role of the reservoir in a biogeochemical cycle. Give an example of a sedimentary cycle with reservoir located in earth’s crust.

The cyclic movement of nutrients from their reservoirs to the plants and then back to the reservoir is called biogeochemical cycle.

The function of biogeochemical cycle is to provide enough amount of nutrients to meet the deficit caused in the ecosystem due influx and efflux.

Phosphorus cycle is the example of sedimentary cycle.

• The reservoir of P is present in rocks.

• As the rocks weather, it releases phosphate dissolved in soil solution.

• Plant absorbs the PO₄^3- present in soil solution.

• Herbivores and other organisms gets P from plants.

• When they excrete or die, decomposed excreta or dead body releases P in the soil. In this manner P again comes back in soil and the cycle continues.