What is the process of succession that begins in a place without any soil?

In a place without any soil, the process of succession begins with the arrival of pioneer species such as lichens and mosses that can grow on bare rock. These pioneer species help break down the rock and create small amounts of organic matter, which eventually leads to the formation of soil. Over time, more complex plant species can then establish themselves in the newly formed soil, initiating succession towards a more diverse and stable ecosystem.