How are primary and secondary succession similar and how are they different?

Answer:

Primary and secondary succession occur after both human and natural events that cause drastic change in the makeup of an area. Primary succession occurs in areas where there is no soil and secondary succession occurs in areas where there is soil. Secondary succession can follow primary succession once pioneer species have contributed to the development of soil during primary succession. Secondary succession, however, can also happen without primary succession if an event caused extensive loss of plant and animal life without destroying the soil. One example of this is wildfires. Soil is not destroyed in these cases and therefore secondary succession can occur.