Download Lesson 4 PPT - sciencewithskinner

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.
pond begins to dry out and
pond-edge plants (cattails
and sedges) take over inside
of dried pond.
Plants that like damp
conditions thrive around
the margins of pond.
Around the ponds edges
the plants are being
replaced by shrubs.
As these plants complete
their life cycle and die, they
add to the accumulating
organic matter which is
making the pond shallower.
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.
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.
VOLCANO
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.