Transcript Ecological Sucession

Ecological Sucession
Defined: the gradual long term
changes
in an altered ecosystem
In the beginning…
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Succession begins when an area is made partially
or completely devoid of vegetation because of a
disturbance.
Common disturbances are fires, wind storms,
volcanic eruptions, logging, climate change,
severe flooding, disease, pest infestation, and
farming
How devoid of vegetation dictates what type of
succession will occur
Types of Succession
1st Primary Succession occurs when both the
vegetation and topsoil or removed or covered.
This typically takes longer to replace
 Pioneer species, the first to occupy the disturbed
area, are often limited to organisms that do not need
soil, ex. Lichen and moss. They help create topsoil
by breaking down rock and replenishing organic
material.
 Examples: Strip mining, Volcanic activity, Severe
wind damage (Hurricane or Tornado) or severe
flooding (Tsunami)
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Types of Succesion
2nd Secondary Succession occurs when topsoil is
left intact and/or not all vegetation is eliminated
This can take up to 150 years to finally reach a stable
ecosystem or what is also known as a climax
community.
 Pioneer species may include grass or annuals, plants
that grow and reproduce 1-2 years but then die.
 Examples of disturbances: fire, farming,
overgrazing, strong storms (Cat. 1-3 Hurricane),
logging, disease
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