ECOLOGICAL SUCCESSION

New Beginnings

Changing Ecosystems

Ecosystems are constantly changing What might cause a change in an

ecosystem?? Human interference (e.g. overhunting,

clearing land for farming, logging, etc.) Natural interference (e.g. Flood, Drought,

Severe storm, wildfire, etc.)

Succession Succession means the act of following in

order or sequence (a series of steps or events)

Ecological Succession: The series of changes that occur in a community over time; predictable

Simple to Complex

Primary Succession

Occurs on surfaces where no soil exists Following volcanic eruptions that create

new islands Following glacial melting which exposes

bare rock Occurs in steps:

Bare rock is exposed

Primary Succession: Pioneer Species

Pioneer species move in First species to populate the area Often times this is lichen (a mutualistic rel.

between fungi and algae); moss; algae Brought in by wind or water

Lichens break down rocks, which are added to the soil

As lichens die and decay, they are added to the soil allowing for other plant species to grow

Primary Succession Other vegetation appears, as the soil becomes more enriched Eventually, grasses and shrubs begin to appear Over time, these plants die, decompose, and continue to enrich soil Allows for larger, more complex plants to grow and develop

Primary Succession

End Product: Climax Community A stable group of plants and animals in a

specified area All plants and animals have necessary

_________ to survive in area, and have individual _______

Secondary Succession

Succession that occurs in areas where an existing community has been disturbed either by natural or human interferences Without removal of the soil; soil still present

Following the interference, ecosystems tend to become restored to their original conditions. Original climax community

Secondary Succession

Primary of Secondary?

Island Succession

A volcanic eruption led to the development of a new island containing only bare rock. YOUR TASK…

Draw the steps of primary succession as they relate to your island Pioneer species Development of soil Plant life Animal life Climax Community