1. ECOLOGICAL SUCCESSION Obj: 11D
Describe how events and processes that occur during ecological succession can change populations and species diversity.

2. What is ecological succession?
orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax is established

3. What differences do you see in these pictures?

4. What disasters could affect the plant population?
Tornados
Hurricanes
Forest fires
Volcanoes
Floods

6. Climax Community The ideal end community in any given ecosystem

7. Primary Succession
Occurs on bare rock or hardened lava on which no soil organisms exist
Beings with arrival of lichens, a pioneer species

8. Pioneer Species Able to grow on barren rock
First organisms to grow during primary succession
Ex: lichens, mosses

10. Secondary Succession
Occurs after an event in which the ecosystem is damaged, but not destroyed.
Because soil remains, secondary succession is faster than primary succession

11. On Hwy 31 going to Kilgore…

14. How long is the time?

16. Succession also in bodies of water

17. large deep lakes shallow ponds grassland

18. How does succession affect population size?
Forest fire or volcanic eruption will decrease population and diversity
If the soil is intact, over time, the populations will recover
Ex: insects deposit eggs in the soil & these eggs can survive and hatch after a fire

20. How does succession affect population diversity?
Animals that survived may move to other regions which reduced competition for other species
Can lead to entirely new ecosystems if new herbivores move in where there were once none.
Eventually carnivores will move in to eat new herbivores.

21. How do population and species diversity change as succession progresses?
Population size and species diversity both increase during ecological succession
Over time, more species are able to survive and become established

22. Smaller producers are replaced by larger ones, such as small trees and shrubs
As insects increase, birds and other animals that eat insects arrive
Eventually a climax community will build again