What is succession

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What is succession?
Wednesday 15th March 2006

• Learning Objectives
• To understand
• The concepts of succession and climatic climax.
• Arresting factors leading to secondary succession
  and plagioclimax.

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Glossary of Keywords
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A model of succession
Climatic climax community
Normal conditions resumed
Removal of human impact
Secondary succession
Secondary succession
Prisere Succession

• Sub-climax
• Edaphic (soil)
• biotic

Plagioclimax
Natural disturbance, e.g. volcano
Human interference, e.g. burning
Bare, inorganic surface
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Plant Succession

• Plant communities that are in succession but not
  at the climax vegetation stage are called seral
  communities or seral stages and the whole
  succession is called a sere. There are two main
  types of sere
• Priseres or primary succession on new inorganic
  surfaces where there has been no pre-existing
  soil formation or vegetation.
• Subseres or secondary succession on sites where
  there has been some previous soil formation and
  vegetation but the climax vegetation or a
  succession has been interrupted by arresting
  factors.

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Primary Succession
Priseres
Xerosere (dry environment)
Hydrosere (wet environment)
Lithosere (bare rock)
Psammosere (sand dunes)
Hydrosere (fresh water)
Halosere (salt water)
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Sometimes the plant succession is interrupted and
the climatic climax vegetation is not achieved.
This is a result of arresting factors such as
Arresting Factors
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Secondary Succession

• People interfere with primary succession. The
  break in succession, if maintained, is a
  plagio-climax. However, if the break in
  succession is natural it is a sub-climax. If
  succession restarts after a sub-climax or
  plagio-climax, it is secondary succession.
• Make notes on secondary succession, using page
  102 of the AS textbook.

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Homework

• Case studies
• Use the information sheets provided and your AS
  Textbook to produce some notes on the worksheet.
• Due next Wednesday.