Question

Starting from a bare rock or a site of volcanic eruption trace the organisms that participate in the process of succession.

Answer 1

Succession on a bare rock :

• The lichens are the pioneer species and invade the bare rocks. They secrete acids which dissolve the rocks, help in their weathering and formation of soil.
• Mosses grow in with the lichens to form a mat over the substratum. Bryophytes or annual grasses succeed the lichens. They are able to hold small amount of soil.
  
• Bigger trees appear in the later stages and are succeeded by other species untill a climax community forms an equilibrium with the environment. It leads to the formation of forest ecosystem.