What Is Ecological Succession?
Ecological succession is the natural, gradual process through which biological communities change and develop over time. When a disturbance occurs—such as fire, volcanic eruption, or human activity—organisms recolonize and rebuild the ecosystem in predictable stages.
Succession helps ecosystems return to stability and biodiversity.
Two Types of Ecological Succession
- Primary Succession
Occurs in lifeless areas with no soil.
Examples: volcanic rock, glacier retreats. - Secondary Succession
Happens after disturbances where soil still exists.
Examples: forest fires, floods, human clearing.
Stages of Succession
- Bare Surface or Disturbed Land
Little to no life present. - Pioneer Species
First organisms to colonize.- mosses
- lichens
- hardy grasses
- Intermediate Species
Soil improves; more organisms appear.- shrubs
- small trees
- insects and small animals
- Climax Community
A stable, mature ecosystem forms.- large trees
- high biodiversity
- stable food webs
Succession is not always linear—disturbances can restart stages.
Why Succession Matters
- rebuilds ecosystems
- increases biodiversity
