What type of ecological succession begins in an area where no biotic community previously existed?

Primary succession is the type of ecological succession that occurs in an area where no biotic community previously existed, such as after a volcanic eruption, glacial retreat, or any event that exposes bare rock or substrate. This process starts from scratch, meaning that it involves the establishment of life in a previously lifeless environment.

In primary succession, pioneer species like lichens and mosses are usually the first organisms to colonize the barren landscape. These organisms help to create soil by breaking down the rock and adding organic material through their life processes and eventual decay. Over time, as soils develop and improve, more complex plants, such as grasses and shrubs, can establish themselves, leading to a more diverse and mature ecosystem.

In contrast, secondary succession occurs in areas where a biotic community has previously existed but has been disturbed or destroyed, such as after a fire or a flood. Climatic succession pertains to changes caused by climate variations, and successional change is a broader term that includes different types of succession without specifying the conditions under which they occur. Thus, the focus of primary succession specifically illustrates how life can begin anew in an environment devoid of previous biological activity.