Ecological succession

Ecological succession is the process of how species compositions change in an ecological community over time.

The two main categories of ecological succession are primary succession and secondary succession. Primary succession occurs after the initial colonization of a newly created habitat with no living organisms. Secondary succession occurs after a disturbance such as fire, habitat destruction, or a natural disaster destroys a pre-existing community.

Both consistent patterns and variability are observed in ecological succession. Theories of ecological succession identify different factors that help explain why plant communities change the way they do.

Succession was among the first theories advanced in ecology. Ecological succession was first documented in the Indiana Dunes of Northwest Indiana by Henry Chandler Cowles during the late 19th century and remains a main ecological topic of study. Over time, the understanding of succession has changed to include a more complex cyclical model that argues organisms do not have fixed roles or relationships. Ecologists and conservationists have since used the theory of succession to aid in developing ecological restoration strategies.

In 1916, Frederic Clements published a descriptive theory of succession and advanced it as a general ecological concept.The process of succession occurs over multiple stages.

A seral community is an intermediate stage found in an ecosystem advancing towards its climax community. In many cases more than one seral stage evolves until climax conditions are attained. A prisere is a collection of seres making up the development of an area from non-vegetated surfaces to a climax community. Depending on the substratum and climate, different seres are found.

According to classical ecological theory, succession stops when the sere has arrived at an equilibrium or steady state with the physical and biotic environment. Barring major disturbances, it will persist indefinitely. This end point of succession is called climax.

The final or stable community in a sere is the climax community or climatic vegetation. It is self-perpetuating and in equilibrium with the physical habitat. There is no net annual accumulation of organic matter in a climax community. The annual production and use of energy is balanced in such a community.