Answer:
Plant development on a layer of rock deposits.
Step-by-step explanation:
Ecological succession is the process by which species structure of an area changes over time. The succession is started by pioneer species which populate the area for the first time. Over time new species arrive and they can either replace the old species or coexist with them. The final stage is the climax community which has a stable species composition. The ecosystem will remain in this form until and unless it is disturbed by an outside factor.
Primary succession is the first stage of succession where the pioneer species begins colonizing previously uninhabited area like plant development on rock deposits. Not every plant species can grow on rock deposits so the one which starts the process is the pioneer species and it is the first to populate the area. It is going to pave way for other species in future.