Ecological succession is the gradual replacement of one community by another over time. Primary succession occurs when a community is wiped out, requiring pioneer species to establish the first ecosystem. Secondary succession follows a similar process but an existing ecosystem is present. Both forms of succession can progress from pioneer species communities to a stable climax community where few new species arrive or leave.

1. How Ecosystems ChangeChapter 6, Lesson 6 ecological succession primary succession secondary succession pioneer species pioneer community climax community

2. ecological succession – the gradual replacement of one community by another

3. primary succession – the gradual build up of a community that was wiped out

4. secondary succession – the gradual replacement of one community by another, but there is already some ecosystem/community there

5. secondary succession – the gradual replacement of one community by another, but there is already some ecosystem/community there secondary succession – the gradual replacement of one community by another

6. ecological succession – the gradual replacement of one community by another

7. pioneer species – the first species to grow in an otherwise lifeless area

8. pioneer community – when the first animals in a community arrive as a result of a pioneer species. A new ecosystem forms.

9. pioneer community – when the first animals in a community arrive as a result of a pioneer species. A new ecosystem forms.

10. climax community – an established community. Few new organisms arrive, few leave. Things are relatively safe and balanced, until another major disaster arises.