1. Changes in Ecosystems: Ecological Succession
Primary & secondary clamation -
Edited from science-class.net

2. Ecological Succession
The process where plants & animals of a particular area are replaced by more complex species over time

3. Primary Succession
occurs in areas where no ecosystem or biological activity has existed previously without any soil
Volcanic eruption areas
Landslides
Retreating glaciers
Emerging islands
Formation of new lakes/rivers

4. A very lengthy process

5. Stage 1 – Pioneer species
Starts with the arrival of living organisms such as lichens that do not need soil to survive
Called PIONEER SPECIES

6. Stage1 continued
Lichen and weathering of rocks create soil.

7. Stage 2 – Mosses & Ferns
Simple plants like mosses and ferns can grow in the new soil

8. Stage 3 - Grasses
The simple plants die as the soil layer thickens, and grasses and wildflowers take over

9. Stage 4 - Shrubs & small softwood trees
Next come bushes and small softwood trees, like pines & aspens

10. Stage 5 – Large hardwood trees
Larger hardwood trees dominate the area, like oaks, maple, elm

11. Secondary Succession
pattern of change in areas where biological activity or an ecosystem has previously existed; already has soil and was once the home of living organisms
Is faster and only stages 2-5
Examples: forest fires, floods, deforestation

14. Climax Communities
Successful high density ecosystem of long-lived tolerant plant species.
Not always the end result because ongoing struggle for resources

15. Videos Primary - http://www.youtube.com/watch?v=vNHnwHaSolA
Secondary -