English: Primary succession is the process characterized by soil and organisms becoming established in an area lacking topsoil and vegetation. The process occurs in the following steps: I. The bare rock is exposed by glaciers or volcanic eruptions. II. Lichens and moss begin to grow on the rock. III. As the lichens and moss die, they decompose, which creates the first organic soil. The rock will slowly decay, and the soil depth will increase as the organisms in the following steps die and decompose. IV. The lichens and grass grow together. V. The grasses and small herbaceous plants thrive. VI. Shrubs and bushes appear in the deeper soil, which contains more water. VII. Smaller trees develop. VIII. Larger trees and shade tolerant plants dominate the landscape. The larger plant species contribute to a faster soil growth rate because of their leaves falling to the surface floor where they decompose. Not all plant species will survive in unison. As large plants grow, they compete for sunlight and nutrients creating unfavorable environments for shade intolerant organisms. Reference image: http://www.dna2life.com/environment/2-instances-primary-secondary-succession