Ecological succession is the gradual process by which ecosystems change and develop over time. There are two types: primary succession, which occurs on new habitats that have never been colonized, and secondary succession, which occurs on previously colonized habitats that have been disturbed. Primary succession from bare rock follows steps from pioneer lichens and mosses breaking down rock to develop soil, to larger plants like ferns and shrubs, and eventually forests over hundreds of years. Secondary succession is faster as soil and seeds are already present, such as after a forest fire or deforestation.

1. Ecological
Succession
UNIT FIVE, LESSON 5.7
BY MARGIELENE D. JUDAN

2. LESSON OUTLINE
Ecological Succession
Primary and Secondary Succession
Succession from Bare Rock
Succession from Disturbed Vegetation

3. Have you ever visited an open field? What
did you observe? What organisms are
commonly could living there?

4. If you have the chance to come back and
visit the same place again after 15 years, do
you think everything will be the same as
before?

5. The next slide is a video animation that will
give you an overview of our lesson today.

7. Ecological succession is the gradual
process by which ecosystems change and
develop over time.
Nothing remains the same and habitats are
constantly changing.

10. Two Types of Ecological Succession
1. Primary - the series of community changes which
occur on an entirely new habitat which has never been
colonized before.
2. Secondary - the series of community changes which
take place on a previously colonized, but disturbed or
damaged habitat.

13. Primary succession is a very long
process, usually 100s to 1000s of years.

14. In primary succession, there is no trace
of a previous community.

15. Nonliving to living community
Starts with no soil

16. Primary succession examples:
1. Succession from a newly quarried rock
2. A new island formed by volcanic activity
3. Succession of sand dunes

17. Primary succession example:
Lawahii was formed by the eruption of an
undersea volcano in the middle of the Pacific
Ocean west of Hawaii and east of Japan. After
hundreds of years plants sprouted on Lawahii.
The gradual growth of vegetation in Lawahii is
an example of primary succession. The pattern
of primary succession is from no soil and being
covered in ash and rock to the growth of
pioneer species such as lichens and moss to
developing weeds, shrubs and trees.
Lawihii born after
volcanic eruption;
notice that it has no
living forms in it

18. While in secondary succession, it happens in an
area that has been previously disturbed or
destroyed.
Living ecosystem > destroyed by calamity > regrowth of the ecosystem

19. It occurs where soil is present.

20. It happens
more rapidly
than primary
succession
because
some soil
and seeds
are left in the
area.

21. Secondary succession examples:
1. Succession of abandoned forest
2. Succession of a burned forest
3. Succession after deforestation

22. Secondary succession example:
Several centuries after the island of Lawahii formed, a fire boke
out killing all of the vegetation and animals that thrived on this
ecosystem. Plants gradually begun to grow once again on this
island. Plants growing once again on Lawahii after a disturbance
such as a fire are examples of secondary succession. The pattern
of secondary succession is from as ecosystem being disturbed by
man or elemental forces to growing annual plants which are
then followed by perennial plants to the growth of shrubs and
eventually the growth of trees. Secondary succession is much
more rapid than primary succession since the vital elements
such as soil, nutrients and seeds are already present at the
location at least to some extent.

23. Succession from a bare rock
The video we watched earlier is an example of a primary
succession from a bare rock

24. Copy and memorize these steps.

25. Succession from a bare rock
1. Bare rock, no organisms - Glacier leaves behind bare
rock; Volcano produces
bare rock with no organisms.
2. Pioneer species begins breaking down rock. Pioneer
species: 1st organism to live in an area. Pioneer
species, usually lichens, grows on rock. Lichens
secrete acids that begin breaking rock into small
particles, which mix with lichen remains to begin
making soil.

26. Succession from a bare rock
3. More complex plants, usually mosses, begin growing when
soil is deep enough, after many years; eventually replace
(succeed) lichens.
Tiny organisms such as insects move in, add their remains to
soil.
4. Larger, more complex plants: As soil gets thicker ferns
succeed mosses.
Grasses and wildflowers may succeed ferns.
When enough soil has developed, shrubs and small trees
move into the area.
5. Forests: Soil may be deep enough after hundreds or
thousands of years for
pine or hardwood forests.

27. Succession from a disturbed vegetation
Kaingin is a slash-and-burn system of farming that can destroy a
previous ecosystem

28. Copy and memorize these steps.

29. All things undergo
succession (they
change). This image is
an example of aquatic
to land community.

30. Aquatic to Land Community Succession

31. Though succession brings about many
positive effects, including the birth of a
new ecosystem, it can also bring about
negative changes.
Because of human exploitation of
resources, our forests have roughly
decreased over the century.

32. Some negative effects
1. Kaingin, deforestation and illegal logging destroys
forests and harms wildlife to extinction.
2. Removing forests promotes soil erosion, making
areas more vulnerable to floods and landslides.
3. To much exploitation exhausts resources (such as
fossil fuels). We should learn and apply the 3Rs
(reduce, reuse, recycle).
4. Land, water and air pollution

33. Sources:
Science Links 7
http://ecologicalsuccessionisabellac.weebly.com/examples-of-
primary-and-secondary-succession-in-lawahii.html
https://quizlet.com/75266290/5-steps-of-primary-succession-
from-bare-rock-to-forests-flash-cards/