Succession

Succession

• Fire, floods, volcanoes, hurricanes, and other natural disasters can change communities in a short period of time.

• Even without a disaster, communities change.

• Succession– The natural processes by which one community of

organisms slowly replaces another in a certain area.– 2 Types

• Primary• Secondary

Primary Succession

• Primary Succession– The series of changes that occur in an area where no

ecosystem previously existed.

• Steps– Land created by volcanic eruption or retreat of glacier– No soil present– Pioneer Species

• The first organisms to live in an area.• Usually lichens or mosses that grow on rocks• Break up the rocks to form soil.

– Soil development– Seeds of plants land in new soil and begin to grow

• Several hundred-thousand years

Primary Succession

Primary Succession

Secondary Succession

• Secondary succession– The series of changes that occur after a disturbance in

an existing ecosystem.– Ex. Fires, hurricanes, tornadoes, farming, logging, or

mining.– Occurs in a place where an ecosystem has

previously existed– Occurs more rapidly than primary succession

• Around 100 years

Secondary Succession

Secondary Succession

Succession Summary

Succession

Creates new ecosystem

Restores previous

ecosystem

Example:New land created

by volcanic eruption

Example:An area

destroyed by fire

Primary Secondary

Summary Questions

• How are primary and secondary succession different?

• What is a pioneer species?

• Give two examples of natural disturbances and two examples of human disturbances that can result in secondary succession.

• Grass poking through the cracks in a sidewalk is an example of succession. Is this primary or secondary succession? Explain.