Ecosystem Introduction First coined by A G Tansley

Ecosystem

Ø Introduction: - First coined by A. G. Tansley in 1935. - Two words namely Eco and System (environment; a complex coordinated unit). - Basic functional unit of ecology.

Structure: - Mainly two components I. Abiotic factors: - Non-living substances - Eg. Soil, water, minerals, p. H, air, light, temperature etc. II. Biotic factors: - Living organisms. - Eg: Plants, animals, soil microorganisms …. . etc. - Biotic factors are depends on abiotic factors for their survival. - Three main groups - Producers, consumers and decomposers.

i) Producers: - Process of photosynthesis. - Eg. Algae, plants etc. - Convert light energy into chemical energy. - Some of the energy is utilized for the growth and development and remaining energy is stored for future use.

ii) Consumers : • Primary consumers: - Producers consuming organisms - Herbivores. - Eg. Cow, buffalo, goat, sheep, rabbit, deer etc • Secondary consumers: - Kill and eat the herbivores - Primary carnivores - Ex: Fox, Wolf, Snake etc. • Tertiary consumers: - Consume secondary consumers - Top consumers. - Ex: Lion, Tiger, Eagle, Vulture etc. • Omnivores: - Consume both producers as well as consumers - Ex: Dog, Cat, Man etc.

iii) Decomposers: - Lastly, the dead parts of plants and animals are decomposed by decomposers. - Ex. Fungi and some bacteria. - Convert larger dead parts into smaller molecules i. e. complex organic substances into simple substances. - Then these molecules are absorbed by other reducers (bacteria). - They take energy and release into the environment in the form of chemicals (minerals). - These minerals are reutilized by the producers.