Succession happens all time, it is the process in which a ecosystem gradually changes over time, a new species grows to gradually replace other species. New, stronger organisms will evolve to better suit the ecosystem and other organisms will be replaced.
There are two different types of succession: primary succession and secondary succession.
Primary succession occurs in an area that is barren, with no vegetation. Primary succession is the process that turns this area into a thriving ecosystem. Primary succession is the development of animal and plant life, and it requires the weathering of rocks over time. It can happen in an ecosystem after there has been serious disturbances, bad enough to wipe out any living organisms, like lava flow or severe wildfires. Primary succession occurs over time making the environment a suitable habitat for many organisms. Moss, lichen and other pioneer species, as well as water and wind, work to begin to create soil. Once soil is created and living conditions become more normal other organisms able to better survive the conditions replace the pioneer organisms.
Secondary succession takes place in an area that has been effected by a disaster, like a forest fire or a hurricane. Secondary succession works to rebuild the once existing ecosystem, or habitat. Differing from primary succession, secondary takes place in an area that already has soil and some living organisms, there for this process is much shorter then primary succession.
