Previous Year Question

An Artificial Ecosystem is an ecosystem created by humans or one whose structure and functioning require continuous human intervention for maintenance.

A Rice Field is an Agroecosystem. It contains the usual components of an ecosystem—Producers, Consumers, Decomposers, soil, water and nutrients—but its structure is mainly controlled by human beings.

In rice cultivation, humans undertake activities such as seed selection, land preparation, irrigation, fertilizer application, weed control, pest management and harvesting. If this management is removed, the ecosystem will gradually cease to remain in its agricultural form because of natural succession.

Rice plants act as Producers. Insects, birds and other organisms in the field may act as Consumers, while microorganisms such as bacteria and fungi function as Decomposers. Thus, ecological processes operate much like those in a natural ecosystem, but the establishment and maintenance of the system depend on human intervention.

In contrast, the Forest, Grassland and Lake given in the question are generally examples of Natural Ecosystems.