Question

Differentiate between.
Autotrophic and heterotrophic succession.

Answer 1

Hint:- Development of plant community in the barren area is named as succession or biotic succession. During the succession, replacement of existing communities by the new community occurs in an orderly sequence in the barren area with time because of change in environmental conditions. Biotic communities are never stable. They're changing more or less over period and space because of the presence of various climatic and environmental conditions.

Complete Answer:-The first community to inhabit a piece of land is termed a pioneer community. The composition and structure of all communities changes constantly in response to the changing environmental conditions. These changes take place in an ordered and sequential manner, parallel with the changes in the physical environment. These changes finally lead to a community that is in near equilibrium with the environment and is called a climax community. The communities or stages which come in between pioneer communities and climax communities are named as transitional or seral communities. The succession within which autotrophic organisms are dominant is named as autotrophic succession while the succession during which heterotrophic organisms are dominant is named as heterotrophic succession.
Inorganic environment favours autotrophic succession because the autotrophs start growing in minerals rich environments whereas heterotrophic succession occurs in an organic environment. After all, the heterotrophs feed on another organism. In autotrophic succession rate of gross photosynthesis is more than the rate of community respiration whereas, in heterotrophic succession, the rate of gross photosynthesis is less than the rate of community respiration. During autotrophic succession, energy flow within the ecosystem is increased because the number of autotrophs continuously increases whereas, during heterotrophic succession, heterotrophs consume energy and this energy flow is reduced.

Note:- During an ecological succession, short-lived organisms are gradually replaced by long-lived and more developed organisms. The species diversity also increases during succession. The major change that takes place during succession is the change in the vegetation. However, these vegetational changes successively affect food and shelter for various varieties of animals. Thus as the succession proceeds, the numbers and types of animals and decomposers also change.