How do communities change after disturbances such as fires or droughts?

In biology, communities change after disturbances through a process known as ecological succession. When a disturbance—such as a wildfire—removes part of a community but leaves the soil and some nutrients intact, the area undergoes secondary succession.

The recovery process typically follows these stages:

• Colonization: Pioneer species, such as insects, weedy plants, and microorganisms, are the first to arrive. These species are adapted to grow and reproduce quickly in disturbed environments.12
• Intermediate Stages: As pioneer species modify the habitat—for example, by improving soil fertility or altering shade levels—they are gradually replaced by hardier intermediate species, including shrubs and small trees.32
• Climax Community: If the area remains undisturbed, the community may eventually reach a state of equilibrium called a climax community, which is a stable structure dominated by a specific set of prominent species.34

Species diversity plays a critical role in this recovery; research shows that species-rich communities are generally more stable and recover faster from disturbances like severe drought than species-poor communities.4