Which one of the following is not a functional unit of an ecosystem?
'Ecosystem function' is the technical term used in the framework to define the biological, geochemical and physical processes and components that take place or occur within an ecosystem. Four important functional aspects of the ecosystem are;
A. productivity., B. Decomposition., C. Energy flow, and D. Nutrient cycling
Productivity refers to the rate of generation of biomass in an ecosystem. During this process, plants convert light energy into chemical energy.
Energy flow - is the flow of energy through the biological food chain. Energy is transferred through the separate trophic levels of a food chain or web by feeding.
Decomposition - is the where decomposers provide food to themselves and eventually return the nutrients to the soil.
All the above options are either biological, geochemical or physical processes that take place in the ecosystem.
Stratification is just the vertical distribution of different species occupying different levels. Therefore stratification is not a functional unit of the ecosystem.