Ecological succession is the gradual change in the structure of a community or ecosystem. There are two types namely: primary succession and secondary succession. In primary succession, the change starts with no presence of life i.e. on a barren piece of land or rock. The pioneer species are organisms that have the ability to survive on bare rocks e.g lichens.
In the image attached, the succession starts with a BARE ROCK, and the first pioneer species are lichens before gradually moving into a climax community. Hence, this is an example of primary succession. Note that, in secondary succession, there is presence of SOIL.
