Types of Succession

Succession is the natural change of an ecosystem over time. As time passes

new species will be introduced to ecosystems. The rate of change

depends on the previous environment.

Primary Succession• There is no previous community• There are rocks, no soil. Rocks must break down into

soil. • This occurs by lichens breaking apart the rock material. • Lichens are a symbiotic relationship between a fungus

and a photosynthetic partner (usually an algae). • Takes a very long time for this succession to occur.

• Centuries

• EX: Barren land, glaciers, new volcanic islands (Hawaii)

Example of when Primary Succession occurs

New Volcanic Islands

Another exampleGlaciers

•

Succession will occur on the new land that is left after the glacier retreats.

Secondary Succession

• There was a previous community that was destroyed somehow

• The soil remains from the previous community• This means lichens do not need to break down the rocks.

• Secondary succession is faster than primary succession• Decades

• EX: forest fire, volcanic eruption

Order of Succession

• Draw a picture of what happens between primary and secondary succession…

• Let’s look at some examples!

Forest Fire in Yellowstone National Park, 1988

The red on the map is the extent of the fire

This photo was taken in Yellowstone National Park near the Old Faithful Geyser in June of 1999, eleven years after the fires.

Burned out trees remain standing, although new trees are rising to take their place.

Mount St. Helens before and after the 1980 eruption

Trees were flattened by the shear force of the blast

Mt. St. Helen 1988

Mt. St. Helen 2001

Mt. Saint Helen is not the only volcano

•The largest volcano in North America is Yellowstone.

•The red line indicates the size of the volcano caldera

•The Mesa Falls ash bed, Huckleberry Ridge ash bed and Lava Creek ash bed all were created when the Yellowstone Super Volcano erupted.

•Would we be safe if it erupted again?

Primary Succession

Rock

Lichen: Pioneer species

Small plants and shrubs

Small trees

Mature Trees

Secondary Succession

Small sun loving plants

Small shrubs and bushes

Small trees Mature Trees

What step is missing? (What has to happen first for secondary succession to happen?)

Order of Succession

• Pioneer Organisms Serel Stages Climax Community– Pioneer Organisms are the first organisms to grow in

an area after the land is exposed. – Serel Stages are the stages of growth in between the

beginning and the mature area. – Climax Community is the mature community that will

grow in an area.