What is the definition of Ecological
Succession?
• The gradual process of change and
replacement of some or all of the species in a
community
What are the two types of
succession?
• Primary Succession and Secondary
succession
What is primary succession?
• A type of succession that occurs on surface
where no ecosystem existed before
Describe the steps of primary
succession on a rock base.
• Lichens colonize rock
• Lichens begin to break down rock, soil begins
to form
• Weathering helps break down rock adding to
soil
• Some Lichens die, adding nutrients to soil
• Moss starts to grow on rocks
• Some moss dies, adding more nutrients to soil
What is secondary succession?
• A type of succession that occurs on a surface
where an ecosystem has previously existed, it
occurs after there is a disturbance to the first
ecosystem.
Name 3 examples of disturbances that
could occur before secondary
succession would begin?
•
•
•
•
•
•
Fire
Hurricane
Clear cutting for farming
Floods
Volcanoes
building
What is a pioneer species?
• The first organisms to colonize any newly
available area and begin the process of
ecological succession
After Mount St. Helen erupted the
prairie lupine colonized the habitat,
how did the lupine make the habitat
more habitable for other plants?
• It “fixed” nitrogen, adding usable nitrogen to
the soil
How have animals assisted in the
secondary succession of
Mount St. Helen?
• By bringing seeds to the ecosystem, either by
carrying them or through their waste
What type of succession is old field
succession?
• Secondary Succession
What are the steps in old field
succession?
• Pioneer grasses and weeds grow
• Taller plants grow, shade out smaller ones
which die
• Trees start growing, shade out taller plants
which die
• Even taller trees take over
• After about 100 years, land may return to
climax community
What does climax community
mean?
• A final and stable community
Which is an example of a climax
community?
B
C
A
In a coral reef ecosystem what
species was present in the climax
community that wasn’t present in
the other reefs?
• Shark
What are examples of natural
disturbances that destroyed part of
the coral reefs?
• Hurricanes and El Nino
Name one benefit of forest fires
• Clear out dead debris
• Opens up pine cones of some species of pine
trees, releasing seeds
• Stimulates bud growth on some pines
• Stimulates growth of some pines