1. Changes in Ecosystems: Ecological Succession

2. Describe the changes you see occurring after the volcanic eruption
Describe the changes you see occurring after the volcanic eruption. [Succession Video] Be specific. Notice what occurs first, did the land change? How small or big were the first plants? How Fast did this occur?

3. What is Ecological Succession?
Natural, gradual changes in the types of species that live in an area

4. Two Types of Ecological Succession
Can be primary or secondary

5. Primary Succession Begins in a place without any soil and No life
Examples
Sides of volcanoes
Landslides
Flooding

6. Pioneer Species
First, lichens (that do not need soil to survive) grow on rocks
Next, mosses grow to hold newly made soil
Known as PIONEER SPECIES

7. Pioneer Species
Low, growing moss plants trap moisture and prevent soil erosion
Lichens break down rock to form soil.

8. Primary Succession
Soil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller pieces
When lichens die, they decompose, adding small amounts of organic matter to the rock to make soil

10. Primary Succession
Simple plants like mosses and ferns can grow in the new soil

11. Primary Succession
The simple plants die, adding more organic material (nutrients to the soil)
The soil layer thickens, and grasses, wildflowers, and other plants begin to take over

12. Primary Succession
These plants die, and they add more nutrients to the soil
Shrubs and trees can survive now

13. Primary Succession
Insects, small birds, and mammals have begun to move into the area
What was once bare rock, now supports a variety of life

14. Secondary Succession
Begins after an event in a place that already has soil and
was once the home of living organisms
Occurs faster and has different pioneer species than primary succession
Example: after forest fires

15. What Differences do you see?

16. Decide which of the following picture are Primary or Secondary Succession

17. Secondary
Why?
Because there are small plants (no pioneer species), and soil is present

18. Primary
Why?
Lichen (pioneer species) present, no soil

19. Secondary
Why?
Because there are small plants (no pioneer species), and soil is present

20. Secondary
Why?
soil is present, previous life existed

21. Primary
Why?
Lichen (pioneer species) present, no soil

22. Primary
Why?
Volcano whipped out existing life… and pioneer species (lichen) are present

23. Climax Community
A stable group of plants and animals that is the end result of the succession process
Does not always mean big trees
Grasses in prairies
Cacti in deserts

24. Ecological Succession - Natural, gradual changes in the types of species that live in an area

25. Primary Succession – no previous life
Secondary Succession – was previously home to organisms

26. Compare Succession Chart Below (4 points)
Primary Succession
Secondary Succession
No Soil
No previous Life
(Pioneer species) Lichen and Moss
No biomass (living organisms)
Event causing Removal of existing life
Soil Present
Seeds, roots, small plants present
Has Biomass (some living organisms)