Which form of succession replaces

an

existing system after a calamity?

Secondary succession

Explanation:

Ecological succession is the term used to describe any series of change in the composition of an ecosystem over a particular period of time. Ecological succession is made up of two types viz: primary succession and secondary succession.

Primary succession involves the formation of a brand new ecosystem by the colonization of a barren area of land e. g bare rock, where no life existed. Secondary succession, on the other hand, is the recolonization of an area by a new set of organisms because the previously existing organisms have been wiped out by certain disasters e. g fire outbreak, hurricanes etc. In secondary succession, there is soil, which makes it possible for new organisms to sprout quickly after the calamity.

Example of secondary succession is when a fire outbreak burns the organisms in a community, allowing the root of grasses to sprout after.