Ecological succession is the process by which the structure of an ecosystem changes over time as it transitions from a bare environment to a climax community. There are two types of succession: primary succession occurs on new land with no soil, as pioneer species like mosses and lichens slowly break down rock to form soil and allow other plants to grow; secondary succession takes place more quickly on previously inhabited land that has been disturbed in some way, like abandoned farmland or burned forests, since soil is already present. In both cases, the composition of species changes as the environment transforms through the stages of succession.

1. Ecological Succession
Ch. 5 part 3

2. Big Idea #4
Succession is the process of change in
the structure of the environment and the
composition of species in an ecosystem
as the environment changes

3. Where do forests come from?
They come about gradually through a
process called ecological succession

4. 2 types
Type 1: primary succession
Brand new land

5. Primary succession
No soil
First species to
come are called
pioneers
 Mosses and lichen
 Can grow on bare
rock
 As they grow they
break apart the rock
and form soil

6. Primary succession
After a loooong time, there will be
enough soil to support small plants like
weeds, grasses, and small shrubs
 Mosses and lichens die off

7. Primary succession
Finally enough soil accumulates to
support trees
And you get a climax community

8. 2 types
Type 2: secondary succession
Old land that has been wiped out
somehow
Examples:
Abandoned
farmland
Burned forests
Polluted streams
Flooded land

9. Secondary Succession
The same thing
happens, but
much more
quickly since
there is already
a soil base

10. Succession
Animal species change through the
course of succession as well