Download Ecological Succession

ECOLOGICAL SUCCESSION
New Beginnings
Changing Ecosystems
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Ecosystems are constantly changing
What might cause a change in an ecosystem??
 Human
interference (e.g. overhunting, clearing land for
farming, logging, etc.)
 Natural interference (e.g. Flood, Drought, Severe storm,
wildfire, etc.)
Succession
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Succession means the act of following in order or
sequence (a series of steps or events)
Ecological Succession: The series of changes that
occur in a community over time; predictable
Simple to Complex
Primary Succession
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Occurs on surfaces where no soil exists
 Following
volcanic eruptions that create new islands
 Following glacial melting which exposes bare rock
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Occurs in steps:
 Bare
rock is exposed
Primary Succession: Pioneer Species
 Pioneer
species move in
 First
species to populate the area
 Often times this is lichen (a mutualistic rel. between fungi
and algae); moss; algae

Brought in by wind or water
 Lichens
break down rocks, which are added to the soil
 As lichens die and decay, they are added to the soil
allowing for other plant species to grow
Primary Succession
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Other vegetation appears, as the soil becomes more enriched
Eventually, grasses and shrubs begin to appear
Over time, these plants die, decompose, and continue to enrich soil
Allows for larger, more complex plants to grow and develop
Primary Succession

End Product: Climax Community
A
stable group of plants and animals in a specified
area
 All plants and animals have necessary _________ to
survive in area, and have individual _______
Secondary Succession

Succession that occurs in areas where an existing
community has been disturbed either by natural or
human interferences
 Without

removal of the soil; soil still present
Following the interference, ecosystems tend to
become restored to their original conditions.
 Original
climax community
Secondary Succession
Primary of Secondary?
Island Succession
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A volcanic eruption led to the development of a
new island containing only bare rock. YOUR
TASK…
Draw the steps of primary succession as they relate
to your island
 Pioneer
species
 Development of soil
 Plant life
 Animal life
 Climax Community