Secondary succession is the process by which ecosystems recover after a disturbance, such as a fire, flood, or human activity. Unlike primary succession, which starts from bare rock or soil, secondary succession begins in areas where soil and some organisms still exist. This allows for a quicker recovery, as seeds and roots may remain in the ground, ready to sprout. During secondary succession, pioneer species like grasses and weeds often appear first, followed by shrubs and eventually trees. Over time, these plants create a more complex ecosystem, restoring habitats for various animals and insects. This process can take years to decades, depending on the severity of the disturbance.