Jimmy Carter1976-1980

Ronald Reagan1980-1988

George Bush Sr.1988-1992

Bill Clinton1992-2000

Barack Obama2008-2016

What does “succession” mean?

George Bush Jr2000-2008

Primary Succession• Defined: Establishment and development of an

ecosystem in an uninhabited environment

Primary Succession• Defined: Establishment and development of an

ecosystem in an uninhabited environment

• Volcanic lava creates new land

New barren land

Primary Succession• Defined: Establishment and development of an

ecosystem in an uninhabited environment

• Volcanic lava creates new land

• Glaciers retreating exposing new land

Rocky land

Frozen glacierNew barren land

Primary Succession• Defined: Establishment and development of an

ecosystem in an uninhabited environment

• Volcanic lava creates new land

• Glaciers retreating exposing new land

Peruvian Andes Mountains

Primary Succession• Defined: Establishment and development of an

ecosystem in an uninhabited environment

• Volcanic lava creates new land

• Glaciers retreating exposing new land

Columbia Glacier in Alaska

Bare Rock

• Lava cools and hardens into rock

Pioneer Species• Defined: First organisms to inhabit new land

• Moss and lichen grow on bare rock

Rocky land

wind

. . . . . .

Pioneer Species• Defined: First organisms to inhabit new land

• Moss and lichen grow on bare rock

Rocky land

. . . . . .

Rocky land

Pioneer Species• Defined: First organisms to inhabit new land

• Moss and lichen grow on bare rock

. . . . . .

Rocky land

soil

Pioneer Species• Defined: First organisms to inhabit new land

• Moss and lichen grow on bare rock

• Dead matter accumulates with rock pieces– Thin soil layer begins to accumulate

Thin layer of soilAllows more growth

Rocky land

soil

The Process Continues• Seeds enter the area and grow

seed

wind

Rocky land

soilsoil

The Process Continues• Seeds enter the area and grow• Small flowers & shrubs accumulate more organic

matter• With new plants, small animals inhabit the area

Rocky land

soil soil

Even More Time Passes• Small trees take root in the accumulated organic

matter

• More animals use the trees as a habitat

Climax Community• Large trees take root

– Overcrowd and out-compete the original smaller trees

• New animals inhabit new forests

Rocky land soil

Secondary Succession

• Changes that take place after a disturbance occurs in an established ecosystem– Forest fires, floods, tree falls…

• Faster scale (soil preexists)

Review

1) What are the first organisms to live within a newly created patch of land called?

2) Give examples of the answer to question #1.

3) What are the final species to live within a newly created patch of land called?

4) How are new areas of land created?

5) Give a few examples how the process of secondary succession can start.

6) How does primary and secondary succession differ? How are they similar?