Answer:
Primary succession is basically the start of a brand new ecosystem. This is when pioneer species form and grow like lichens and some grasses. Secondary succession is when the ecosystem is already started and it's continuing to grow. During this time populations of other species begin to inhabit the ecosystem like shrubs and trees and some animals. Both of these processes take years to complete. An example of an event would be a volcanic eruption, and a wild fire.
Step-by-step explanation: