Ecological succession is the process by which the composition or structure of a biological community evolves over time. There are two types of succession - primary succession, which occurs in environments without soil such as after a volcanic eruption, and secondary succession, which occurs in areas with existing soil such as abandoned farms. During primary succession, pioneer communities of organisms that can survive in harsh conditions are the first to colonize an area, followed by changes to more complex communities in a predictable order. Secondary succession follows a similar pattern on land that previously supported life.

1. Succession
8SCIENCE
Wed. Nov. 17/
Thurs. Nov. 18

2. How does succession relate to Ecology?
• Ecosystem level
• Ecological succession:
– When one community of organisms (living things)
changes to a different community: plants, animals and
other organisms change and are affected
– This usually happens in a PREDICTABLE order

3. Individual thinking:
• What happens to an
ecosystem when a volcano
explodes?
• THINK and write what you
think INDEPENDENTLY FOR 2-
3 minutes
• Think about:
– What would the ecosystem look
like?
– What would happen to the
plants and animals and other
organisms living around the
volcano?
• Contribute one idea from
each group

4. Two types
of succession
• Primary succession:
– Changes that happen in an
environment that does not
have soil
– E.g.: volcano after
explosion, desert
• Pioneer community: The
first organisms to move
into a new environment
– Eg.: what could grow here?
Could some organisms use
it as a place to live?

5. Animation of Primary Succession
• Click here to see Primary Succession:

6. Two types of
succession
• Secondary:
– Changes to the
environment occur in a
place with soil, or where
organisms once lived
– E.g. unused farm or fields,
abandoned lots: parking
lot
• Climax community:
– Community at the end of
succession
– All species may be the
same