Ecology Lecture Notes

Process of Ecological Succession (PPT)


Process of Succession

Stages of Ecological Succession
(Formation of an Ecosystem)

What is Ecological Succession?

Definition: Ecological succession is the gradual and sequential replacement of one community by the other in an area over a period of time. According to E.P. Odum (1971), the ecological succession is an orderly process of community change in a unit area. It is the process of change in species composition in an ecosystem over time. In simpler terms, it is the process of Ecosystem Development in nature.

Population Vs Community

Population: The group of individuals of a particular species occupying in a unit area. Example: population of Aedes aegypti (yellow fever mosquito) in an area.

Community: A community can be defined as a combination of different populations in an ecosystem. For example a pond ecosystem may consist of populations of Spirogyra (algae) Diatoms, Frogs, Fishes and Insects.

The community in an ecosystem is NOT stable. It passes through many developmental stages in definite sequence over a period of time. These developmental stages in most of the cases will be from simple to complex and it is collectively called as community dynamics.

Process of Ecosystem Succession

The ecological succession is a complex process and it may take thousands of years. Frederic Clements in 1916 for the first time proposed the sequential phases of an ecological succession. The process of succession is completed through a series of sequential steps as given below:

(1).      Nudation
(2).      Invasion
(3).      Competition and Co-action
(4).      Reaction
(5).      Stabilization (climax)

Continue reading