Changes in Ecosystems:
Ecological Succession
Adapted from: www.science-classes.net
Definition:
• Natural, gradual changes in the types of
species that live in an area (in the
community)
• The “recovery” of a region after
“disturbance”.
Primary Succession
• Begins in a place without any soil
– Sides of volcanoes
– Landslides
– Flooding
• PIONEER SPECIES –
do not need much/any
soil to survive.
– Lichens
Primary Succession
• Primary Pioneer organisms help make
soil.
• Die!
Decompose!
Compost?
Primary Succession
• Simple - mosses and ferns
http://www.uncw.edu
http://uisstc.georgetow
n.edu
Primary Succession
• Simple plants ….DIE!
• Soil layer thickens grasses, wildflowers
http://www.cwrl.utexas.edu
Primary Succession
• More plants…DIE!
• Even more soil
• Shrubs, trees
http://www.rowan.edu
Primary Succession
• Consumers supported
• High biodiversity
http://p2-raw.greenpeace.org
Secondary Succession
• Begins in a place that already has soil
– Forest fires
– Old fields
• Faster
• Different species involved
http://www.geo.arizona.edu
http://www.ux1.eiu.edu
http://www.agen.ufl.edu
Climax Community
• Highest biodiversity
• A stable group of organism.
• Does not always mean big trees
– Grasses in prairies
– Cacti in deserts