Transcript Ecosystem Development

Ecosystem Development
What is an Ecosystem?
• All the living and nonliving things in an
area.
– Examples:
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Ponds
Forests
Lakes
Rivers
• Ecosystems develop and change over
periods of time.
How do Ecosystems Develop?
• Ecological Succession
– The process by which an existing community
in an ecosystem is gradually replaced by
another community
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TIME
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Pioneer organisms
• Pioneer organisms:
– The first plants to populate an area
• They change the environment so that other
organisms are able to live in the same area
• Example:
– Lichens are the pioneer organisms on bare rock and
change the rock into soil
• Each new population causes changes in the
environment, which allow other populations
to develop and replace the earlier ones.
Climax Communities
• Climax Community:
– Ecological succession finally leads to a
community of populations that does not
change any further
• A climax community
– A mature stable community that is the final stage of
ecological succession
Put these in the correct Order:
Pioneer Organisms ----------------------------------------------> Climax Communities
Where does Succession occur?
• In areas that have been cleared of existing
vegetation
• Causes:
– Wild Fires
– Over Grazing
– Deforestation
– Natural Disasters
Some Review
(incase you didn’t get it the first
time)
Organisms Role in a Ecosystem
• Each species in a community uses the
resources of the environment and obtains
food in its own particular way
– Niches
• The particular way in which species functions in an
ecosystem
• Described as:
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A role of a species in the community
By the kind of food an organism needs
By the place an organism lives and reproduces
By the time of day the organisms is active
What happens if two different
species occupy the same niche?
• Competition!
– Species will fight for the same resources
• One species will be eliminated and the other will
be dominant in that niche
Species A
# of
species
Species B
Time
Predator-Prey Relationship
• Boom and Bust Cycle
What is Carrying Capacity?
• The number of individuals who can be
supported in an ecosystem
• Once it is reached there will be
competition for resources (organisms die)
Requirements For an Ecosystem:
• In order for an ecosystem to be selfsufficient (stable) it must have…
– A constant source of energy
• Energy is not recycled
– Materials need to be recycled
• CO2, O2, N2, H2O