How does primary succession differ from secondary succession?

Primary succession is characterized by the process that takes place in lifeless regions where soil has not yet formed. This often occurs following events such as volcanic eruptions or glacial retreats, where the landscape is devoid of vegetation and organic matter. The initial colonizers in these environments are typically lichens and mosses, which can survive in harsh conditions and begin the process of soil formation. Over time, as they die and decompose, they contribute organic material, allowing for the establishment of more complex plant life.

In contrast, secondary succession occurs in areas where an ecosystem has been disturbed but where soil and some living organisms still remain, such as after a forest fire, flood, or human activities like farming. The pre-existing soil and seed banks allow for relatively quicker recovery and regrowth compared to primary succession.

Understanding the distinction between these two types of ecological succession is crucial for grasping how ecosystems recover and develop over time after disturbances. The fact that primary succession starts from bare rock or lifeless regions fundamentally differentiates it from secondary succession, which builds upon an existing ecological framework.