1. Ecological Succession
Equilibrium in Ecosystems

2. What is Succession?
Succession is the series of predictable changes that occur in a community over time.
Succession helps an ecosystem to recover and return to a state of equilibrium after a fire, volcano or other disaster.

3. Primary Secondary and Types of Succession
There are two types of succession:
Primary
and
Secondary

4. Primary Succsession
Primary Succession occurs where no ecosystem previously existed.

5. How Can There Be an Area Where No Ecosystem Previously Existed?
New Volcanic Island
Area of Rock Uncovered
by retreating Glaciers

6. Steps in Primary Succession
A new island is formed through long series of volcanic eruptions. No life exists on this new rocky material at first.

7. Start your Timeline in Your NB
What will you draw here to represent the beginning of primary succession?
Year Zero

8. What Can Live on the New Island?
The newly created island is made of volcanic rock, but no soil.
Most large plants with roots
can’t grow without soil.
Most animals can’t survive without plants, so how can life exist on this new island?

9. The First Plants
Small plants like lichens and mosses do not have roots. These small plants have the ability to grow on rocks and slowly break- down the rocks to produce soil.

10. Add to your Timeline in Your NB
What type of plants do you think will first reappear? Draw them here.
Year Zero
Months to years later

11. Lichens and Mosses on Rocks

12. Succession continues…
The newly produced soil can now start to support small plants with some degree of roots systems.
Grasses with
small root systems
will typically start
to grow next.

13. Grass

14. Weathering of Rock Continues
As more plants grow, the roots of the plants break down the rock further to produce richer and more abundant soil.
Succession continues with larger plants now having the ability to grow.
On many islands, ferns
will now begin to grow.

15. Add to your Timeline in Your NB
Think about what you know about succession, then draw what type of plant you now think will grow in this area
Year Zero
Months to years later
Years later

16. Ferns

17. More Weathering… Over time, larger and more
complex plants will begin to grow.
Flowering plants will now be seen.
The types of producers become more varied and this sets the stage for animals to be able to survive.

18. Tropical Flowering Plants

19. Succession continues…
Larger and larger plants now grow, providing food, shelter and nesting places for a variety of animals. Many different types of trees now begin to grow.

20. Add to your Timeline in Your NB
After many years have passed, what type of plants will now be found in this area if no other disturbances occur? Draw these here.
Year Zero
Months to years
later
Years later
Many Years Later

21. Monkey Pod Tree

22. Ecosystem Reaches Equilibrium

23. The new ecosystem is now full of varied types of life, plants and animals live successfully together.

24. Disaster Strikes…

25. The island is burned to the ground
The island is burned to the ground. The trees, other plants and animals are destroyed. All that is left is the rock and soil. Equilibrium is destroyed and the process of succession must once again begin.

26. Start your Timeline in Your NB
What will you draw here to represent the beginning of secondary succession?
Year Zero

27. Secondary Succession
Secondary Succession occurs following a disturbance to an ecosystem, such as after a devastating fire.
Secondary succession occurs
naturally after hurricanes,
floods, and tornadoes.
Secondary succession also occurs after
farming, logging and mining have disturbed an ecosystem.

28. Steps of Secondary Succession
Secondary succession occurs in a place where an ecosystem has previously existed.
Secondary succession can happen faster because soil has already been produced.
If soil was not lost in the disturbance, plants can grow more quickly.

29. After the disturbance, grasses or small plants will begin to grow on existing soil

30. Ferns or small shrub-like plants can quickly fill in areas where grasses and smaller plants first grew

31. Large plants eventually overtake the island.
Monkey Pod Tree

32. The renewed ecosystem is now full of varied types of life, plants and animals live successfully together.

33. The Ecosystem Once Again Reaches Equilibrium

34. Complete your Timeline in Your NB
What will you draw here to represent the events that happen in secondary succession?
Year Zero