Ecological succession describes the changes in species composition over time in a community. Primary succession occurs in areas without soil, like new volcanic islands, and involves pioneer species creating soil from rocks over long periods of time until a climax community develops. Secondary succession follows a disturbance like a fire or flood where soil remains and the community transitions through different species compositions more quickly until a climax community is reestablished.

1. Succession
SB4c.Relate environmental
conditions to successional
changes in ecosystems.

2. Read the introduction at the top of the page,
then answer #1 under “Important Stuff”
Ecological Succession changes that
take place in a community over time.

3. Primary Succession
1. Creates new colonies of organisms
in new areas where no soil exists
(EX: islands formed by
volcanoes)
2. Takes a long time (soil must first
be made by the breaking down of
rocks)

4. Primary Succession
3. The community continues to grow
until limiting factors become too
great.
4. Eventually it become a climax
community (Climax community -
stable, mature; not much change
occurring)

5. Primary Succession

6. #2 & #3 “Important Stuff”
 Pioneer species – 1st organisms to move
into an area (examples: mosses & lichen)
 Pioneer species help create soil by
secreting acids that help to break down
rocks.

7. Primary Succession

8. Secondary Succession
1. Changes that occur to a community
after a natural disaster has destroyed
it
2. "Old" species die and new species
may move in
3. This one doesn’t take as long as
primary because the soil is already
established.

9. 4. Eventually reaches a climax
community

10. Secondary Succession

11. Secondary Succession