Download Ecological Succession

Ecological Succession

A series of predictable changes that occur
in a community over time.

Ecosystems change over time especially
after disturbances, as some species die
out and new species move in.

Ecological model: a model scientists use
to predict changes that will happen in an
ecosystem that occurs over a long
distance or over a long period of time.
number of different species present typically increases.
How many changes over time can you find?
Primary Succession

Succession that begins in an area with no remnants of an older
community

No life present

only rock and eventually soil

Occurs at a very slow rate

Examples:
 retreating
 emerging
 formation
glaciers
islands
of new lake
Secondary Succession

The existing community almost completely destroyed by
disturbances.

Proceeds faster than primary succession, because soil is
present.


As a result, new and surviving vegetation can regrow
rapidly, reach climax community faster
Examples:

Fire

Floods

Bulldozers
Climax Community

Last stage of succession

Succession does not always follow the same stages
for every community.

Healthy ecosystems will often reach the original
climax community.

Example: succession caused by storms and forest
fires

Some ecosystems, due to extensive human caused
disturbances, may never fully recover

Examples: succession due to clearing and
farming of tropical rainforests (deforestation)

Caused by pollution