An ecological succession refers to the progressive succession of a group of species or community over time. In this regard, there is usually one dominant type of species or community thriving in an ecosystem and where a stable climax community is established. An ecological succession may span decades or millions of years. It may be primary, secondary, or cyclic.
A secondary succession is a type of succession that follows after a primary succession. A primary succession is an ecological succession that occurs following an opening of uninhabited, barren habitat or that occurs on an environment that is devoid of vegetation and usually lacking topsoil. It is when the area has not been occupied and eventually pioneer species thrive and have stabilized into an ecological community. A secondary succession is one in which the primary succession has been disrupted or destroyed resulting in the disturbance in the stability and the destruction (or reduction) of the ecological community in that area. An example of secondary succession is the development of new inhabitants to replace the previous community of plants and animals that has been disrupted or disturbed by an event (e.g. forest fire, flood, harvesting, epidemic disease, pest attack, etc.).