Natural and Artificial Ecosystem
i) Natural ecosystems are those which are mostly free from human disturbances, such as tropical forests, grasslands, oceans, lakes and deserts.
ii) Artificial or man-modified ecosystems are formed as a result of human modification of the natural ecosystems. For example, man has transformed natural forests and grasslands into crop fields. An extreme example of an artificial ecosystem is a city. Increasing human interference has destroyed many natural ecosystems and replaced them with artificial ecosystems,'such as crop fields, urban centres and industrial estates.
All ecosystems are fully integrated with the neighbouring ecosystems and communicate with each other in varying degrees through the import and export of both energy and nutrients. An ecosystem is a dynamic system characterised by energy flow and nutrients cycling. Substances constantly flow through it, and there are sufftcient supplies of energy within the ecosystem to allow for this flow to take place. See Figure as shown below. Ecosystems also possess considerable self-regulating ability, called homeostasis. due to which they tend to recover from minor perturbations.