Definitions (Ecosystem)

ECOSYSTEM

Ecosystem: The delicate and dynamic balance that exists between biotic and abiotic component of an environment is known as ecosystem.

Ecology: The branch of science which deals with the interrelationship between the biotic and abiotic factors of an ecosystem.

Producers: The organisms which can prepare their food are called producers.

Consumers: Those organisms which cannot prepare food themselves and depend upon producers for their food are called consumers.

Decomposers: The saprophytic organism that feed on dead and decaying organic matter and decompose them into simpler forms.

Food chain: The process of transfer of energy from one trophic level to another through a series of eating and being eaten.

Food web: The network of various food chains which are interconnected at various trophic levels.

Ecological pyramid: The graphical presentation of number, biomass and accumulated energy at different trophic level in a food chain.

Biogeochemical cycle: The circulation of nutrient elements like carbon, hydrogen etc through physical world and biological world.

Carbon cycle: The cyclic process in which carbon is circulated continuously through the living and non-living component of biosphere.

Nitrogen cycle: The cyclic process in which nitrogen is circulated continuously through the living and non-living component of biosphere.

Water cycle: The circulation of water in different form in the biosphere is called water cycle.

Nitrogen fixation: The process of conversion of free nitrogen gas of the atmosphere into nitrites and nitrate in the soil is called nitrogen fixation.

Nitrification: The process of conversion of ammonia into nitrites and nitrates which can be taken by plants.

Denitrification: The process of conversion of nitrates salt present in soil into free nitrogen is called denitrification.

Ammonification: The process in which the proteins of plants and animals are broken into ammonium salt by the action of ammonifying bacteria.

Symbiosis: The close association of two different organisms in which both are benefited, e.g. Rhizobium bacteria in the root nodules of leguminous plants.

Nitrogen fixing bacteria: Those soil bacteria which are capable of fixing atmospheric nitrogen into nitrates.

Aquatic ecosystem: The ecosystem which exists in water.

Terrestrial ecosystem: The ecosystem which exists on land.

Food pyramid: The pyramidal structure which shows the relationship between various trophic level of an ecosystem on the basis of amount of food consumed by the trophic levels.

Pyramid of biomass: The pyramidal structure which shows the relationship between various trophic level of an ecosystem on the basis of their biomass.

Pyramid of number: The graphical representation which shows the relationship between various trophic level of an ecosystem in terms of their number.

Pyramid of energy: The graphical representation which shows the relationship between various trophic level of an ecosystem in terms of energy.

Primary consumers: The consumers which consume green plants directly.

Secondary consumers: The consumers which feed on the primary consumers.

Tertiary consumers: The consumers which feed on the secondary consumers.

Biosphere: Largest unit of biological system in which many ecosystem can operate together.

Abiotic components: The non-living environment of an ecosystem.

Biotic component: The group of living organism of the ecosystem.

Nitrogen assimilation: The process of conversion of nitrogen compound into complex organic molecule like protein that become a part of living organism.

Biological fixation: The process of conversion of atmospheric nitrogen into usable compounds of nitrogen like nitrites with the help of soil bacteria and other microbes is called biological fixation.

Trophic level: The step representing organisms in a food chain at which the transfer of food and energy takes place.