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