Ecological Succession

1. Ecological Succession New Beginnings

2. Changing Ecosystems • Ecosystems are constantly changing • What might cause a change in an ecosystem?? • Human interference (e.g. overhunting, clearing land for farming, logging, etc.) • Natural interference (e.g. Flood, Drought, Severe storm, wildfire, etc.)

3. Succession • Succession means the act of following in order or sequence (a series of steps or events) • Ecological Succession: The series of changes that occur in a community over time; predictable • Simple to Complex

4. Primary Succession • Occurs on surfaces where no soil exists • Following volcanic eruptions that create new islands • Following glacial melting which exposes bare rock • Occurs in steps: • Bare rock is exposed

5. Primary Succession: Pioneer Species • Pioneer species move in • First species to populate the area • Often times this is lichen (a mutualistic rel. between fungi and algae); moss; algae • Brought in by wind or water • Lichens break down rocks, which are added to the soil • As lichens die and decay, they are added to the soil allowing for other plant species to grow

6. Primary Succession • Other vegetation appears, as the soil becomes more enriched • Eventually, grasses and shrubs begin to appear • Over time, these plants die, decompose, and continue to enrich soil • Allows for larger, more complex plants to grow and develop

7. Primary Succession • End Product: Climax Community • A stable group of plants and animals in a specified area • All plants and animals have necessary _________ to survive in area, and have individual _______

8. Secondary Succession • Succession that occurs in areas where an existing community has been disturbed either by natural or human interferences • Without removal of the soil; soil still present • Following the interference, ecosystems tend to become restored to their original conditions. • Original climax community

9. Secondary Succession

10. Primary of Secondary?

11. Island Succession • A volcanic eruption led to the development of a new island containing only bare rock. YOUR TASK… • Draw the steps of primary succession as they relate to your island • Pioneer species • Development of soil • Plant life • Animal life • Climax Community