Transcript Ecology

Ecology
Food Chains and Food Webs
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BI 6.a-Students know biodiversity is the sum
total of different kinds of organisms and is
affected by alterations of habitats.
BI 6.e-Students know a vital part of an
ecosystem is the stability of its producers and
decomposers.
BI.6.f-Students know at each link in a food
web some energy is stored in newly made
structures but much energy is dissipated into
the environment as heat. The dissipation
may be represented in an energy pyramid.
Standards:
BI 6.a-Biodiversity is total number of
different livings things in an area.
Biodiversity is affected by changing
habitats.
 BI 6.e-Producers and decomposers
maintain the stability (balance) of
ecosystems. How?
 BI.6.f-At each link in a food web some
energy is stored, but most energy is lost
as heat.
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Ecology Standard Explanations
SWBAT:
 Explain the role of biodiversity in
maintaining the balance of an ecosystem.
 Demonstrate how energy is transferred
and lost in an ecosystem.
 Explain the various roles of organisms in
maintaining the stability of an ecosystem.
 Understand the interaction between living
and nonliving factors in an ecosystem.
Objectives:
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Every ecosystem includes both living
(biotic) and nonliving (abiotic) factors.
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Life in an ecosystem requires a source of
energy.
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The biodiversity of an ecosystem
maintains the stability of an ecosystem,
and altering habitats decreases this
biodiversity.
Review-Key Concepts So Far
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Key Concept: Food chains and food webs
model the flow of energy in an ecosystem.
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Food chains-A sequence that links species
by their feeding relationships.
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Follows the connections between one
producer and a single chain of consumers.
What are food chains?
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Owl
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Mouse
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Grasshopper
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Grass
What are food chains?
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Herbivores-eat only plants (grasshopper)
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Omnivores-eat both plants and animals
(kangaroo mouse)
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Carnivores-eat only other animals (owl)
What are the different types of
consumers?
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Detritivores-organisms that eat only dead
or decaying organic matter (detritus).
(Millipedes)
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Decomposers-Detritivores that break
down organic matter into simpler
compounds. They return vital nutrients
back to the ecosystem. (Fungi)
What are the different types of
consumers?
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Herbivores
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Omnivores
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Carnivores
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Detritivores
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Decomposers
What are the different types of
consumers?
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Trophic levels-are the levels of
nourishment in a food chain.
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Energy flows up the food chain from the
lowest trophic level to the highest.
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Producer-Herbivore-Carnivore
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Primary consumer, Secondary Consumer,
Tertiary Consumer
What are trophic levels?
Food web-is a model that shows the
complex network of feeding relationships
and the flow of energy within an
ecosystem.
 At each link some energy is stored by an
organism and some is lost.
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The stability of an ecosystem depends on
the producers.
What are food webs?
What are food webs?
Energy pyramid-A diagram that compares
energy used by producers, primary
consumers, other trophic
levels.(kilocalories)
 Shows how energy is distributed among
trophic levels
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Start with large base (producers) and
each level gets smaller because energy is
lost (10%) as heat
What happens to the energy in
a food web?
Energy Pyramid
Energy Pyramid
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SunlightProducersHerbivores
Carnivores
Producers-use energy to make food
Herbivores-use energy to grow and for
cellular respiration. Most of the energy is
lost as heat.
Carnivores-Most of the energy is lost as
heat
Each level in food chain contains less
energy
What happens to the energy in
the pyramid?
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What is the difference between food webs
and food chains?
Why does the stability of ecosystems
depend on producers?
What is the role of decomposers in
ecosystems?
What are trophic levels?
What happens to energy at each trophic
level?
Summary Questions: