Question

what is main difference between primary and secondary succession

Answer 1

Primary succession is the colonization of living organisms into an area that was not previously colonized by any living things. An example of this would be succession after a glacier recedes or after a new island forms from oceanic volcanoes.

Secondary succession is the regeneration of the living community after a major disturbance. For example, after a forest is clear-cut the trees are removed but some small plants, the soil, and soil organisms remain. The forest will slowly regenerate.