Ecological Succession Gradually Transforms Ecosystems
Ecological succession
Ecological succession describes the process of gradual changes in species composition and abiotic factors in an ecosystem over time.
Species and Abiotic Factors Interact to Shape Ecosystems
- Species Modify the Environment: Pioneer species influence abiotic factors such as soil formation and nutrient levels.
- Abiotic Factors Shape Species Composition: Changes in light availability, temperature, and soil conditions favor different species as succession progresses.
This continuous feedback loop between species and abiotic variables drives succession.
Primary Succession Begins on Bare Surfaces
Primary succession occurs where no soil exists, such as after volcanic eruptions or glacier retreats.
ExampleLichens and mosses colonize bare rock, breaking it down to create soil for grasses and shrubs.

More on primary succession in C4.2.13.
Secondary Succession Follows Disturbances in Established Ecosystems
Secondary succession takes place in areas where soil is present, but vegetation has been removed, like after a forest fire.
ExampleGrasses and wildflowers are followed by shrubs and trees, restoring the ecosystem over time.


