Ecological Succession

1
Ecological Succession

• http//www.youtube.com/watch?vxExdEXOaA9Afeature
  related

2
Our goals

• describe the process of ecological succession,
  with reference to terms such as pioneer species
  and climax community

3
Burns Bog

• How did the bog begin?
• What could naturally happen to the bog over time?

4
Burns Bog is not alone. Ecosystems are always
changing

• This is because of natural and human
  disturbances.
• The changes in a community composition over time
  is called _____________________________

5

• What are some natural and human disturbances that
  disturb an ecosystem and cause succession?
• Natural
• Human

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Primary Succession

• Occurs on areas
• ___________________________________.
• Ex. Land after a volcanic eruption, rock
• Organisms that colonize such areas are called
• ____________________________________.

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• First species to inhabit land where no soil
  exists are called ______________
  _______________(ex. lichen on a rock)
• As they grow, lichens produce acids that break
  down rocks
• Over many years, a thin layer of soil develops
  from broken-down rock and dead lichen.

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• Now, species of moss are able to establish
• They further change the soil, and enable other
  plant species to establish

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• Each species changes the environment in some way
• -sometimes making it easier for other species to
  establish
• (_______________________)
• -sometimes making it impossible for earlier
  species to continue to live there
• (________________________)
• Sometimes, different plants can colonize an area
  at the same time
• (________________________)

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Diagram Credit Shades of Green
(http//library.thinkquest.org/17456/main1.html)
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• Succession can lead to a collection of organisms
  called a ______________________________described
  by the most obvious species they contain.
• The process is complex and the resulting
  community cannot always be predicted and is not
  always the same

12
Secondary Succession

• Occurs after a disturbance, when community
  interactions tend to restore the ecosystem back
  to its original condition

Diagram Credit Shades of Green
(http//library.thinkquest.org/17456/main1.html)
13
What does an undisturbed climax community look
like?

• Old growth forests have a combination of
  _________ and ______________
• trees that are both _________ and
  _____________.