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SECONDARY SUCCESSION
I. Plant/ecological succession - one species replaces another species in an ecosystem.
Succession is a series of predictable changes over time in the kinds of plants growing in
an area.
II. Secondary succession
A. Secondary succession begins in an area where the natural community of
organisms has been disturbed or destroyed, but the soil remains. For
example: fire, abandoned farms, clear cutting of forests, and heavily
polluted streams.
B. Secondary succession is far more common. It occurs in an area where life
once existed but has then been destroyed.
C. Secondary succession occurs after a disturbance of an existing
community that removes or damages the vegetation, but does not
remove, destroy, or cover the soil.
D. Once the disturbance stops, the community will begin secondary succession,
changes in the vegetation that will lead back to a climax community.
E. For example, imagine a forest that has been destroyed by a wildfire.
Again, for a period of time, no living organisms may exist in the area.
Before long, however, certain types of plants begin to reappear.
1. Starts WITH SOIL. Root systems undisturbed in the soil, stumps and other
plant parts from previously existing plants can rapidly regenerate.
2. Faster than primary succession. Since the soil is already in place,
secondary succession can take place five to ten times faster than primary
succession. There is no need to form soil.
F. It is important to remember that the abiotic factors (such as weather,
temperature, wind, and humidity) affect the nature of the plant community.
Succession Questions/Review
1. What is succession?
2. A good example of ecological succession is when one species of plants
________________ another species of plants in an ecosystem.
3. An undersea volcano erupts and forms a new island. Over the course of time,
what type of plant would most likely be the first species to survive on the new
island?
4. If loggers clear-cut the Emergent, Canopy, and Understory layers from the rain
forest, what type of succession will occur?
5. What is the sequence of succession after a forest fire?
6. Do the pictures above show the stages of primary or secondary succession?
7. Why does secondary succession occur more rapidly than primary succession?
8. Look at the picture below. Is this primary or secondary succession? Explain
your answer.
9. Describe (IN DETAIL) Primary and Secondary Succession.
Primary Succession
Secondary Succession
10. Identify two natural disturbances and two human disturbances that can
result in secondary succession.
11. What type of succession is being described?
A huge fire raged through Yellowstone National Park. After the fire, all that remained in
that part of the forest were thousands of blackened tree trunks sticking out of the
ground like charred toothpicks. But within a few months, signs of life had returned. New
grass shoots were followed by tree seedlings. The forest was coming back!
12. ___________________ takes place on an area that is originally completely empty of
life. There is no soil. ________________________takes place on existing soil.
13. ______________________ is far more common. It occurs in an area where life once
existed but has then been destroyed.
14. What are two sources of new rock? Where does the new rock come from?
15. How do lichens and mosses help make soil?