Primary Succession
Primary succession always starts with a barren landscape that no plant life has ever been. The first plants to appear are annual plants that only last about a year. Next, perennial plants and grasses begin to grow and stay around year after year. After that, shrubs grow into the environment. Next the shrubs are over shadowed by smaller trees. Finally, large trees are growing and the land is no longer barren but a healthy environment for animals and plants.
Secondary Succession
Secondary succession starts with an area that was cleared by man, flood, fire, etc. This type of succession is usually faster than primary because plants have lived on the land before so the soil has some nutrients in it.
Primary and secondary succession are similar in the way that they both have plants slowly grow into a barren environment. However, primary succession happens when plants grow into an environment that has never had plants there before and secondary succession is when plants regrow in the environment after a flood, trees being cut down, hurricane, and anything that clears the land.