1) during the primary succession, the ecosystem appears in the place where nothing grew before (there was no soil)
2) secondary succession occurs by the displacement of one ecosystem by another, or at the place of disappearance of the ecosystem as a result of any incidents (a new ecosystem arises at a place where there is already fertile soil)
3) an example of primary succession – overgrowth of volcanic slopes after an eruption; an example of a secondary – overgrowth of burnt places after a forest fire
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.