What does primary succession refer to in ecological terms?

Primary succession is defined as the process of establishing a new ecological community in an area that is devoid of life and soil. This typically occurs in environments that have experienced significant disturbances, such as volcanic eruptions, glacier retreats, or landslides, which expose bare rock or create new landforms that do not have any existing soil or biological community.

During primary succession, pioneer species like lichens and mosses colonize the bare substrate. These organisms play a crucial role in soil formation as they contribute organic matter when they die and decompose. Over time, as soil depth and quality improve, more complex plant species, such as grasses and eventually shrubs and trees, can establish themselves, leading to a more diverse ecosystem. This sequence of changes represents the gradual progression from a lifeless area to a mature and stable ecological community.

Understanding primary succession helps illustrate the resilience of ecosystems and their ability to recover from severe disturbances over time, contrasting with secondary succession, which involves recovery on previously inhabited land.