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- Population 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 melt and expose rock

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

7. Lichen Fungi and algae act as one organism. The algae produces energy through photosynthesis. The fungi obtains water and minerals and protects the algae cells.

8. Primary Succession- Rock

9. Climax community- a stable, mature community that undergoes little or no succession

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

11. Primary succession-

12. 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

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

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

15. Secondary succession-

17. Pond Succession