Succession

1
Succession

• Predictable change in the composition of a biotic
  community over time
• Successional or seral community undergoing
  successional change
• Climax community successional change has ended

2
Succession Types

• Primary succession invasion of life onto abiotic
  enviroment
• ex. lichens mosses on rocks start making soil
  airborne seeds germinate in sand/ash
• Secondary succession changes after biotic
  community is established or after a disturbance
• ex. fire meadow old field thicket -- forest

3
Succession Processes

• Succession occurs because of
• Facilitation growth of one species increases the
  growth of another
• ex. Lichens/mosses create soil benefits other
  plants legumes fix nitrogen, fertilizing soil
  benefits other plants
• Competition growth of one species hinders the
  growth of another
• ex. Tall-growing trees shading out shrubs

4
Succession Plant traits

• Early succession
• Shade intolerant
• Fast growing
• Many seeds
• Seed dispersal is key
• Fugitive of pioneer species

• Late succession
• Shade tolerant
• Slow growing
• Fewer seeds
• Less dispersal
• Climax species

5
Succession and Disturbance

• Disturbance resets succession to an earlier stage
• Fire
• Weather damage (wind, ice, hail)
• Flooding
• Animal damage (trampling, browsing, defoliation)
• Frequent severe disturbance prairie / savanna
• Infrequent small disturbance forest gaps

6
Succession habitat management

• Most human activities tend to act as
  disturbances, moving succession back to earlier
  stages (or stopping it!)
• e.g., agriculture (and development)

7
Things to remember

• Definition of succession
• Primary and secondary
• Mechanisms of succession
• Facilitation competition
• Effects of disturbance on succession species
  diversity
• Factors influencing future vegetation of a site

8
Project

• Write an ESSAY discussing how to measure Primary
  Secondary Succession in lower Plaquemine's?
• In your essay you must give examples that
  Succession it is occurring.
• And include what you think will happen over the
  next 5 years.