1. Succession in Ecosystems

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

3. Primary succession- 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 organisms- Pioneer organisms: the first organisms to colonize a new site Ex: lichens are the first to colonize lava rocks

7. Primary Succession- Rock

8. Climax community- Climax community: a stable, mature community that undergoes little or no succession Example: a mature forest

9. Primary succession-

10. Secondary succession- 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

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

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

13. Secondary succession-

15. Pond Succession

16. Check for understanding…

17. The diagram below represents a process that occurs in nature.This diagram can be used to illustrate the (1) effects of reduced competition between different types of plant life (2) effect of human intervention on a stable ecosystem (3) ecological succession from bare rock to stable ecosystem (4) evolution of mosses to trees over 200 years

18. Which statement best describes one of the stages represented in the diagram below? (1) The mature forest will most likely be stable over a long period of time. (2) If all the weeds and grasses are destroyed, the number of carnivores will increase. (3) As the population of the shrubs increases, it will be held in check by the mature forest community. (4) The young forest community will invade and take over the mature forest community.