Community Ecology

The living organisms and their non-living (abiotic) environment are in-separably inter-related and interact upon each other. Any unit in which there is interaction between organisms and their physio-chemical environment and between organisms and materials between the two, is called ecosystem. Ecosystem is a dynamic system where the biotic and abiotic components are constantly acting and reacting upon each other bringing forth structural and functional changes. A community, or biocenose, is an aggregate of organisms which form a distinct ecological unit. Community units may be very small like the community of invertebrates and fungi in a decaying log. The extent of a community is limited only by the requirement of a more or less uniform species composition. A different community occurs in each different habitat and environmental unit of larger size, and in fact the composition and character of the community is an excellent indicator of the type of environment that is present. Communities may be distinguished as major or minor. Major communities are those which, together with their habitats, form more or less complete and self sustaining units or ecosystems, expect for the indispensable input of solar energy. Minor communities, often called societies, are secondary aggregations within a major community and are not, therefore, completely independent units as far as circulation of energy is concerned.