1. Succession in Ecosystems

2. Succession- a series of changes in a community in which new populations of organisms gradually replace existing ones

3. Primary succession- colonization of new sites by communities of organisms – takes place on bare rock

4. Primary succession- New bare rock comes from 2 sources: 1. volcanic lava flow cools and forms rock

5. Primary succession- New bare rock comes from 2 sources: 2. Glaciers retreat and expose rock

6. Pioneer Species the first organisms to colonize a new site Ex: lichens are the first to colonize lava rocks

7. Primary Succession- Rock

8. Climax community- the final stable plant community which may reach a point of stability that can last for hundreds or thousands of years.

9. Climax community- Ex: In most of Virginia, the climax community would be a deciduous oak–hickory forest

10. Primary succession-

11. Secondary succession- sequence of community changes that takes place when a community is disrupted by natural disaster or human actions – takes place on existing soil

12. Secondary succession- Ex: A fire levels portions of a forest

13. Secondary succession- Ex: A farmer plows his field

14. Secondary succession-

16. Pond Succession