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?

A

B

C

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