primary succession is one of two types of biological and ecological succession of plant life, occurring in an environment. Usually lacking soil, such as a lava flow.

Succession

secondary succession is a process started by an event.(forest fire, harvesting, and hurricane) that reduces an already established ecosystem (a forest or a wheat field) to a smaller population of species, and as such secondary succession occurs on preexisting soil whereas primary succession usually occurs in a place lacking soil

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