Which one of the following is NOT a functional unit of an ecosystem?

Stratification

The correct answer is Option (1) - Stratification

Stratification is formation of different layers of strata. It is a functional unit of forests. Many forests consist of 3 strata, namely a layer of tree, a layer of shrubs and a layer of herbaceous plants. Ecosystem consists of living and nonliving things. Productivity is the rate of generation of biomass in an ecosystem. Decomposition is the process of breakdown of dead organic material. The upper layer of soil is the site for decomposition in the ecosystem. In an ecosystem, energy flow from producers to consumers to decomposers and then back to the environment.

The other options—Energy flow, Productivity, and Decomposition—are all functional aspects that play key roles in the functioning of an ecosystem:

• Energy flow involves the transfer of energy through various trophic levels in the ecosystem.
• Productivity refers to the rate at which energy is converted into biomass by producers (e.g., plants) in an ecosystem.
• Decomposition involves the breakdown of organic matter by decomposers, contributing to nutrient cycling in the ecosystem.