in the primary succession, the first stage starts from nothing. pioneer plants are those that can grow without soil, such as lichens. Lichens begin breaking down a rock. it starts in a very plain and dry environment. these could come from volcanos. in the secondary succession they start from soil remains.
in the second stage of the primary succession, mosses usually star growing on the rocks with no soil. this is all natural.
in the third stage of the primary succession, grasses, herbs, scrubs and tree seeding (basically are starting to grow
in the fourth step of primary succession, is when the grasses grow and displace the pioneer species.
the fifth stage of primary succession, is when more nutrient in soil allows for shrub growth.
in the final stage, the soil increases in depth, and allows growth for trees.