Question

in which case does secondary succession occur? where soil is present where soil is not present where only rocks are found

Explanation:

Secondary succession occurs in areas where soil is present. For example, after a forest fire, if the soil remains intact, new plants can grow from the seeds in the soil. In contrast, primary succession occurs where there is no soil (e.g., on newly formed volcanic islands or bare rock areas). So, the presence of soil is a key factor for secondary succession.

Answer:

where soil is present