Give general information about ecosystem and give examples of various ecosystems.

(N/A) An ecosystem can be visualized as a functional unit of nature where living organisms interact among themselves and also with the surrounding physical environment.
Ecosystems vary greatly in size,from a small pond to a large forest or a sea.
Many ecologists regard the entire biosphere as a global ecosystem,as a composite of all local ecosystems on Earth.
Since this system is too large and complex to be studied at one time,it is convenient to divide it into two basic categories: terrestrial and aquatic.
Examples of terrestrial ecosystems include forests,grasslands,and deserts.
Examples of aquatic ecosystems include ponds,lakes,wetlands,rivers,and estuaries.
Crop fields and aquariums may also be considered as man-made (artificial) ecosystems.
Studying the structure of an ecosystem helps us understand the input (productivity),the transfer of energy (food chain/web,nutrient cycling),and the output (degradation and energy loss),along with the relationships and cycles created by these energy flows.