Primary succession
Occurs in areas where no soil or little soil is present, such as on bare rock, volcanic lava, or dunes. It starts from scratch, so to speak, with pioneer species like lichens and mosses that can tolerate harsh conditions. Over time, these organisms break down the rocks and begin to create soil. Primary succession is a slow and gradual process, often taking hundreds or even thousands of years to establish a stable, mature ecosystem.
Secondary succession
This happens in areas where the soil is already present but has been disturbed or altered. This can result from events like wildfires, logging, or human activities. Since there's already existing soil, the process is faster than primary succession. Weeds and other opportunistic plants are typically the first to colonize the area, followed by a succession of plant and animal species that gradually restore the ecosystem to its pre-disturbance state.