Seconary succession is one of the two types of ecological succession of plant life. As opposed to primary succession, secondary succession is a process started by an event (e.g. forest fire, harvesting, hurricane) that reduces an already established ecosystem (e.g. a forest or a wheat field) to a smaller population of species, and as such secondary succession occurs on preexisting soil where as primary succession usually occurs in a place lacking soil. A harvested forest going back from being a cleared forest to its original state, the "climax community" (a term to use cautiously), is an example of secondary succession. Each stage a community goes through on its way to the climax community in succession can be referred to as a "serial community."