The following will be covered in the lesson: Predict how an ecosystem will change as a result of major changes in an abiotic and/or biotic factor.

SUCCESSION Series of predictable changes that occur in a community over time.

Over time aquatic ecosystems fill in with sediment and dead plant material creating a land ecosystem.

A colony of beavers dam a stream, creating an open pond in the forest, and the surrounding trees die. Plants that like damp conditions thrive around the margins of pond. As these plants complete their life cycle and die, they add to the accumulating organic matter which is making the pond shallower. pond begins to dry out and pond-edge plants (cattails and sedges) take over inside of dried pond. Around the ponds edges the plants are being replaced by shrubs. Finally, the shrubs are replaced by trees...

PRIMARY SUCCESSION Regular pattern of species replacement where nothing has lived before.

PIONEER SPECIES The first species to populate an area where succession is starting. Able to live in harsh conditions. Can grow in poor soil.

VOLCANO When the volcano finishes erupting pioneer species will slowly begin taking root on the newly created mountain. This would be primary succession since nothing has grown there before.

SECONDARY SUCCESSION Series of changes in an area where the ecosystem has been disturbed, but where soil & organisms still exist. Occurs after disturbances such as fires and floods.

Clear Creek Fire, Salmon-Challis N.F./ 2000

This forest in Yellowstone is going through secondary succession after wildfires burned thousands of acres.