VPE 511: Environment and Environmental Hygiene (2+1)

CONCEPT OF AN ECOSYSTEM

• We may consider the living component of ecosystem from the point of view of levels of organization for better understanding of ecosystem and ecology. All living things are made up of protoplasm which is the physical basis of life. The protoplasm is organized into cells which are again, organized into tissue. The tissues organize themselves into organs, organs into systems and systems into organisms. One kind of organisms (one kind of species) living together to form a small or large assemblage is called a population. Several population of different plant and animal species interacting with one another are called a biotic community or community. A community with its interacting populations for energy and nutrients constitutes and ecosystem.
• The largest ecosystem is called biosphere or ecosphere (entire habitable part of the earth) in which plants and animals , living part of the community interact with environment (non-living part)
• Ecosystem can be broadly classified into (i) natural ecosystem (ii) man made ecosystem. The natural ecosystem comprises Terrestrial ecosystem (Forest, Grassland and Desert E.S) and Aquatic ecosystem  ( Freshwater E.S - Lake, Pond, Ditch, Swamp, River, Spring and Stream E.S and Marine E.S - Ocean and Sea E.S). Man-made ecosystem (or) Artificial ecosystem are those ecosystems which are modified by human activities. For example, crop field, urban, industrial laboratory and space, space crafts, gardens, parks and aquariums are artificial ecosystems.

STRCTURE AND FUNCTIONS OF ECOSYSTEM