TERMINOLOGY OF ECOLOGY
Ecological Succession: Vegetation is hardly stable, and thus dynamic, changing over time and space. Although comparatively less evident than vegetation, animal populations, particularly lower forms, also show dynamic character to some extent. Succession is a natural process by which different groups or communities colonize the same area over a period of time in a definite sequence. The succession, which starts from a primitive substratum without any previous living matter, is known as the primary succession, whereas that starting from the previously built up substratum where living matter already existed, is known as the secondary succession. If the existing community, as a result of its reaction with the environment, causes its own replacement, then such a succession is known as autogenic succession but if the replacement of the existing community takes place due to the influence of any external force or condition, then it is called allogenic succession.
Climax: In the natural process of succession, one community continues to follow another, until a stage comes when a type of community cannot be displaced under the prevailing environmental conditions. This final, terminal community, that can maintain itself more or less indefinitely in equilibrium with the prevailing environment, is known as the climax community and the stage is said to be the climax.
Biome: A complex of several types of communities, some in climax stage and others in different stages of succession, maintained more or less similar climatic conditions is known as a biome.
Ecosystem: In a given area, the biotic assemblage of all the organisms, plant as well as animal communities, interacts with its physical environment in such a manner that there is a flow of energy leading to clearly defined trophic structure, biotic diversity and material cycles within a system, is known as an ecological system or ecosystem. An ecosystem is the whole biotic community in a given area plus its abiotic environment.
Biosphere: The earth’s living organisms interacting with their physical environment may be considered as a giant ecosystem, which is the largest and most nearly self- sufficient biological system we know, and this is designated as the biosphere or ecosphere. Thus the planet earth along with the atmosphere, hydrosphere and lithosphere which sustain life is known as biosphere.
Standing State: The amount of inorganic substances, such as P, S, C, N, H etc. present at any given time in the environment of an ecosystem, is known as the standing state or standing quality. Standing Crop: The amount of living material, present in a component population at any time, is known as the standing crop, which may be expressed in terms of numbers or weight per unit area.
Biomass: Biomass is the standing crop expressed in terms of weight (i.e. organism mass) of the living matter present.
Food Chain: In any ecosystem, various living organisms are arranged in a definite sequence according to their food habits. Plants are producers which are eaten by herbivores, which in turn are eaten by carnivores. This transfer of food energy from the source in plants through a series of organisms with repeated eating and being eaten is known as a food chain in an ecosystem.
Food Web: Under natural conditions in the same ecosystem, depending upon the variety of organisms, there generally operate a number of linear food chains at a time. These chains are interlinked with each other at several points. This interlocking pattern of a number of food
chains forms a web-like arrangement known as food-web.
Ecological Succession: Vegetation is hardly stable, and thus dynamic, changing over time and space. Although comparatively less evident than vegetation, animal populations, particularly lower forms, also show dynamic character to some extent. Succession is a natural process by which different groups or communities colonize the same area over a period of time in a definite sequence. The succession, which starts from a primitive substratum without any previous living matter, is known as the primary succession, whereas that starting from the previously built up substratum where living matter already existed, is known as the secondary succession. If the existing community, as a result of its reaction with the environment, causes its own replacement, then such a succession is known as autogenic succession but if the replacement of the existing community takes place due to the influence of any external force or condition, then it is called allogenic succession.
Climax: In the natural process of succession, one community continues to follow another, until a stage comes when a type of community cannot be displaced under the prevailing environmental conditions. This final, terminal community, that can maintain itself more or less indefinitely in equilibrium with the prevailing environment, is known as the climax community and the stage is said to be the climax.
Biome: A complex of several types of communities, some in climax stage and others in different stages of succession, maintained more or less similar climatic conditions is known as a biome.
Ecosystem: In a given area, the biotic assemblage of all the organisms, plant as well as animal communities, interacts with its physical environment in such a manner that there is a flow of energy leading to clearly defined trophic structure, biotic diversity and material cycles within a system, is known as an ecological system or ecosystem. An ecosystem is the whole biotic community in a given area plus its abiotic environment.
Biosphere: The earth’s living organisms interacting with their physical environment may be considered as a giant ecosystem, which is the largest and most nearly self- sufficient biological system we know, and this is designated as the biosphere or ecosphere. Thus the planet earth along with the atmosphere, hydrosphere and lithosphere which sustain life is known as biosphere.
Standing State: The amount of inorganic substances, such as P, S, C, N, H etc. present at any given time in the environment of an ecosystem, is known as the standing state or standing quality. Standing Crop: The amount of living material, present in a component population at any time, is known as the standing crop, which may be expressed in terms of numbers or weight per unit area.
Biomass: Biomass is the standing crop expressed in terms of weight (i.e. organism mass) of the living matter present.
Food Chain: In any ecosystem, various living organisms are arranged in a definite sequence according to their food habits. Plants are producers which are eaten by herbivores, which in turn are eaten by carnivores. This transfer of food energy from the source in plants through a series of organisms with repeated eating and being eaten is known as a food chain in an ecosystem.
Food Web: Under natural conditions in the same ecosystem, depending upon the variety of organisms, there generally operate a number of linear food chains at a time. These chains are interlinked with each other at several points. This interlocking pattern of a number of food
chains forms a web-like arrangement known as food-web.
