Download Ecological Succession

Ecological Succession
http://www.youtube.com/watch?v=
V49IovRSJDs&list=PL7A7502811
06CD067&index=60&feature=plpp
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Ecological Succession
• Ecosystems are constantly changing in
response to natural and human
disturbances.
• As an ecosystem changes, older
inhabitants gradually die out and new
organisms move in, causing further
changes in the community.
• The organisms change the ecosystem
over time.
Ecological Succession
• Ecological Succession = the series of
predictable changes that occur in a
community over time
• Succession can occur because of slow
changes in the physical environment or
sudden disturbances, like a natural
disaster or human activity.
Primary Succession
• Primary Succession – establishment
of plant communities on newly formed
habitats previously lacking plants
–Due to a disturbance that leaves no
soil behind: volcanic eruptions or
glaciers receding
–Begins with bare rock
–Rock  lichen  moss  grass 
shrub  oak/hickory forest
What are lichen you say?
What Are Lichen?
• It is not just one organism, but two
organisms living in a symbiotic
relationship (fungi and algae)
• Lichen is a PIONEER SPECIES, which
means it is the first species to populate
an area.
• Lichen can grow on bare rock. They
help break up the rock as they grow.
When they die, they help form the soil
so that plants can begin to grow.
Primary Succession
• Can take 1000 years
Secondary Succession
• Secondary Succession –
return of vegetation to its
former state following a
disturbance (fires, floods,
mudslides, tornadoes, etc.)
Grass  shrub  oak/hickory forest
Secondary Succession
• Faster than
primary
succession
• May only take a
few hundred
years
Secondary Succession
• Begins with soil on which the
previous ecosystem has been
removed (by fire, agriculture,
flooding, etc.)
• First species are small plants
(grasses) instead of lichen, because
soil is already present and doesn’t
have to be formed before things can
grow.
Climax Community
• A stable group of plants and
animals that is the end result of
the succession process
– Deciduous Forest = many large deciduous
trees, a few coniferous trees, and lots
of biodiversity
• Does not always mean big trees
– Grasses in prairies
– Cacti in deserts
Article Analysis
• What did you learn or find interesting from
the article?
• How does it relate to Succession?
• Did it discuss Primary or Secondary
Succession?