Succession occurring after flood is:

The correct answer is Option (3) → Secondary succession

Option (1) Hydrarch succession — Incorrect. Hydrarch succession starts in water (a pond or lake) and slowly turns it into land.

Option (2) Primary succession — Incorrect. Primary succession starts where no living organisms and no soil were ever present, such as bare rock or newly cooled lava. A flooded land still has soil.

Option (3) Secondary succession — Correct. A flood destroys the plant community but leaves soil or sediment behind, so life returns by secondary succession, which is faster than primary succession.

Option (4) Mesarch succession — Incorrect. Mesarch succession takes place in areas of moderate moisture; it is named by the starting habitat, not by a disturbance such as a flood.

Note: This question is from the topic “Ecological Succession” in Chapter 14, Ecosystem, of the pre-rationalised NCERT book. This portion is not in the present NCERT book, where the chapter is now Chapter 12, Ecosystem. The extract below is from the pre-rationalised edition.

NCERT Extract (Pre-rationalised edition, Chapter 14, Ecosystem):
Ecological Succession – “… Secondary succession begins in areas where natural biotic communities have been destroyed such as in abandoned farm lands, burned or cut forests, lands that have been flooded. Since some soil or sediment is present, succession is faster than primary succession.”