Question

Which of the following statements regarding ecological succession is correct?

• A. It is the rapid change that takes place only in the abiotic components of an ecosystem
• B. It is the gradual and predictable change in species composition that occurs in a given area
• C. It always occurs in areas where no living organisms ever existed
• D. The number and types of different species remain constant during ecological succession

Answer 1

The correct option is B It is the gradual and predictable change in species composition that occurs in a given area

Ecological succession is a steady and gradual change in the species composition of an area with the changing environment.

It is a predictable change that is orderly, sequential and in accordance with the changing physical environment.

During succession, some species colonise an area and their populations become more numerous, whereas populations of other species decline and even disappear, this can happen either due to human activities or by natural means.

Ecological succession is of two types:

Primary succession – In this type of succession, there will be the appearance of species for the first time, such areas would have never been previously inhabited; it is barren and lacks fertile soil. For example, newly cooled lava, newly created reservoirs, etc.

Secondary succession – In this type of succession, natural communities develop in an area that was earlier occupied by living organisms that somehow were lost due to many reasons like floods, deforestation, etc.