1. Aim: How do ecosystems change over time?

2. Ecological Succession1
The process by which an ecosystem changes over time – often from a barren piece of land to a complex ecological community (depending on climate) 1 2 3 4 5

3. Ecological Succession In a Forest
As time passes grasses grow & then get replaced by shrubs and eventually a forest will form.
Why do the grasses disappear?
The large shrubs and trees prevent light from reaching the grasses.

4. Ecological Succession in Ponds & Lakes:
As time progresses, the pond gets filled in with dead organic matter. The dead organic matter takes the place of the water in the pond or lake.
Eventually (through succession) a forest may form where the pond once was.

5. What is the final state of ecological succession
A climax community with great
biodiversity

6. Plant adaptation / succession 1:48

7. Destruction of Climax Communities
Fires, volcanic eruptions, tsunamis, deforestation, acid rain.
Their destruction often (but not always) means the birth of a NEW community via succession.

8. Are forest fires an ecosystems worst nightmare? Why or why not?

9. Fire in the Forest 2:25

10. Soil Formation:
Lichens (fungus and green algae) & weather break down rock into its minerals.
Dead Organic materials are added to the minerals

11. Maintaining Soil:
The plant roots hold on to the soil & prevent erosion (washing away of valuable material).
How could erosion cause a problem for an ecosystem?