Which of the following correctly compares the changes that take place in an ecosystem during primary succession and secondary succession

Ecological succession is the process of gradual change of a community's ecological structure. It is further divided into primary succession and secondary succession.

Explanation:

Primary succession: Following events occur during primary succession-

A barren wasteland is occupied by a single species which is also known as the pioneer species.The pioneer species starts to reproduce and grow and soon invites other organisms to build a community.Examples of pioneer species are lichens, small plants and grasses.The climax community finally formed will contain trees like oak and banyan.

Secondary succession: Following events occur in secondary succession-

Already existing habitat, which has been devastated by natural calamities or man made events, is re-established.Natural calamities include flood, rain or forest fires and man made include construction, etc.In this case, all life forms are not destroyed, as it is in the case of primary succession. Small herbs, grasses are available.Initially the pioneer species in this are insects and weeds. Also, secondary succession takes less time to reach climax community than primary succession.